COVID-19 vaccines represent a great scientific and public health achievement in the face of overwhelming pressures from a global pandemic, preventing millions of hospitalizations and deaths due to COVID-19 vaccines in the United States. Over 675 million doses of COVID-19 vaccines have been administered in the United States, and over 80% of the U.S. population has had at least 1 dose of a COVID-19 vaccine. Over the course of the COVID-19 pandemic in the United States, over one million people died from COVID-19, and over six million were hospitalized. It has been estimated that COVID-19 vaccines prevented more than 18 million additional hospitalizations and more than 3 million additional deaths due to COVID-19 in the United States. From the beginning of the COVID-19 pandemic in 2020 through June 2023, ACIP had 35 COVID-19 focused meetings and 24 votes for COVID-19 vaccine recommendations. ACIP had the critical task of rapidly and thoroughly reviewing emerging and evolving data on COVID-19 epidemiology and vaccines, as well as making comprehensive population-based recommendations for vaccine policy and considerations for implementation through a transparent and evidence-based framework. Safe and effective COVID-19 vaccines, recommended through transparent policy discussions with ACIP, remain the best tool we have to prevent serious illness, hospitalization and death from COVID-19.

COVID-19 vaccines protect against severe COVID-19-associated outcomes, including hospitalization and death. As SARS-CoV-2 has evolved, and waning vaccine effectiveness has been noted, vaccine formulations and policies have been updated to provide continued protection against severe illness and death from COVID-19. Since September 2022, bivalent mRNA COVID-19 vaccines have been recommended in the United States, but the variants these vaccines protect against are no longer circulating widely. On September 11, 2023, the Food and Drug Administration (FDA) approved the updated (2023-2024 Formula) COVID-19 mRNA vaccines by Moderna and Pfizer-BioNTech for persons aged ≥12 years and authorized these vaccines for persons aged 6 months-11 years under Emergency Use Authorization (EUA). On October 3, 2023, FDA authorized the updated COVID-19 vaccine by Novavax for use in persons aged ≥12 years under EUA. The updated COVID-19 vaccines include a monovalent XBB.1.5 component, which is meant to broaden vaccine-induced immunity and provide protection against currently circulating SARS-CoV-2 XBB-sublineage variants including against severe COVID-19-associated illness and death. On September 12, 2023, the Advisory Committee on Immunization Practices recommended vaccination with updated COVID-19 vaccines for all persons aged ≥6 months. These recommendations will be reviewed as new evidence becomes available or new vaccines are approved and might be updated.

To reduce the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) and its associated impacts on health and society, COVID-19 vaccines are essential. The U.S. government is working to produce and deliver safe and effective COVID-19 vaccines for the entire U.S. population. The Advisory Committee on Immunization Practices (ACIP)1 has broadly outlined its approach for developing recommendations for the use of each COVID-19 vaccine authorized or approved by the Food and Drug Administration (FDA) for Emergency Use Authorization or licensure.1 ACIP’s recommendation process includes an explicit and transparent evidence-based method for assessing a vaccine’s safety and efficacy as well as consideration of other factors, including implementation.2 Because the initial supply of vaccine will likely be limited, ACIP will also recommend which groups should receive the earliest allocations of vaccine. The ACIP COVID-19 Vaccines Work Group and consultants with expertise in ethics and health equity considered external expert committee reports and published literature and deliberated the ethical issues associated with COVID-19 vaccine allocation decisions. The purpose of this report is to describe the four ethical principles that will assist ACIP in formulating recommendations for the allocation of COVID-19 vaccine while supply is limited, in addition to scientific data and implementation feasibility: (1) maximize benefits and minimize harms; (2) promote justice; (3) mitigate health inequities; and (4) promote transparency. These principles can also aid state, tribal, local, and territorial public health authorities as they develop vaccine implementation strategies within their own communities based on ACIP recommendations.

Four COVID-19 vaccines are currently approved for primary series vaccination in the United States under a Biologics License Application or authorized under an emergency use authorization (EUA) by the Food and Drug Administration (FDA), and recommended for primary series vaccination by the Advisory Committee on Immunization Practices (ACIP): 1) the 2- or 3-dose monovalent mRNA BNT162b2 (Pfizer-BioNTech, Comirnaty) COVID-19 vaccine; 2) the 2- or 3-dose monovalent mRNA mRNA-1273 (Moderna, Spikevax) COVID-19 vaccine; 3) the single-dose adenovirus vector-based Ad26.COV.S (Janssen [Johnson & Johnson]) COVID-19 vaccine; and 4) the 2-dose adjuvanted, protein subunit-based NVX-CoV2373 (Novavax) COVID-19 vaccine. The number of doses recommended is based on recipient age and immunocompromise status (1). For additional protection, FDA has amended EUAs to allow for COVID-19 booster doses in eligible persons (1). Because COVID-19 vaccines have demonstrated decreased effectiveness during the period when the Omicron variant (B.1.1.529) of SARS-CoV-2 predominated, bivalent booster doses (i.e., vaccine with equal components from the ancestral and Omicron strains) were considered for the express purpose of improving protection conferred by COVID-19 vaccine booster doses (2). During September-October 2022, FDA authorized bivalent mRNA vaccines for use as a booster dose in persons aged ≥5 years who completed any FDA-approved or FDA-authorized primary series and removed EUAs for monovalent COVID-19 booster doses (1). Pfizer-BioNTech and Moderna bivalent booster vaccines each contain equal amounts of spike mRNA from the ancestral and Omicron BA.4/BA.5 strains. After the EUA amendments, ACIP and CDC recommended that all persons aged ≥5 years receive 1 bivalent mRNA booster dose ≥2 months after completion of any FDA-approved or FDA-authorized monovalent primary series or monovalent booster doses.

The NVX-CoV2373 (Novavax) COVID-19 vaccine is a recombinant spike (rS) protein nanoparticle vaccine with Matrix-M adjuvant to protect against infection with SARS-CoV-2, the virus that causes COVID-19. On July 13, 2022, the Food and Drug Administration (FDA) issued Emergency Use Authorization (EUA) for the Novavax vaccine for primary COVID-19 immunization of unvaccinated adults aged ≥18 years, administered as 2 doses (5 μg rS and 50 μg Matrix-M adjuvant in each dose) 3 weeks apart (1). On July 19, 2022, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for use of the Novavax vaccine in persons aged ≥18 years for the prevention of COVID-19.* In the per-protocol(†) efficacy analysis, vaccine efficacy (VE) against reverse transcription-polymerase chain reaction (RT-PCR)-confirmed symptomatic COVID-19 was 89.6% (95% CI = 82.4%-93.8%). The Alpha variant (B.1.1.7) of SARS-CoV-2 was the predominant circulating variant during the period of case accrual for VE assessments. Cases of myocarditis or pericarditis were reported in temporal association with vaccination, suggesting a possible causal relationship. The ACIP recommendation for the use of the Novavax COVID-19 vaccine is interim and will be updated as additional information becomes available. The adjuvanted, protein subunit-based Novavax COVID-19 vaccine provides an additional option for unvaccinated adults, increasing flexibility for the public and for vaccine providers. Vaccination is important for protection against COVID-19.

On June 17, 2022, the Food and Drug Administration (FDA) issued Emergency Use Authorization (EUA) amendments for the mRNA-1273 (Moderna) COVID-19 vaccine for use in children aged 6 months-5 years, administered as 2 doses (25 µg [0.25 mL] each), 4 weeks apart, and BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine for use in children aged 6 months-4 years, administered as 3 doses (3 µg [0.2 mL] each), at intervals of 3 weeks between doses 1 and 2 and ≥8 weeks between doses 2 and 3. On June 18, 2022, the Advisory Committee on Immunization Practices (ACIP) issued separate interim recommendations for use of the Moderna COVID-19 vaccine in children aged 6 months-5 years and the Pfizer-BioNTech COVID-19 vaccine in children aged 6 months-4 years for the prevention of COVID-19.* Both the Moderna and Pfizer-BioNTech COVID-19 vaccines met the criteria for immunobridging, which is the comparison of neutralizing antibody levels postvaccination in young children with those in young adults in whom efficacy had been demonstrated. Descriptive efficacy analyses were also conducted for both Moderna and Pfizer-BioNTech COVID-19 vaccines during the period when the Omicron variant of SARS-CoV-2 (the virus that causes COVID-19) predominated. No specific safety concerns were identified among recipients of either vaccine. ACIP recommendations for the use of the Moderna COVID-19 vaccine and the Pfizer-BioNTech COVID-19 vaccine in children aged 6 months-5 years and 6 months-4 years, respectively, are interim and will be updated as additional information becomes available. Vaccination is important for protecting children aged 6 months-5 years against COVID-19.

Certain laboratorians and health care personnel can be exposed to orthopoxviruses through occupational activities. Because orthopoxvirus infections resulting from occupational exposures can be serious, the Advisory Committee on Immunization Practices (ACIP) has continued to recommend preexposure vaccination for these persons since 1980 (1), when smallpox was eradicated (2). In 2015, ACIP made recommendations for the use of ACAM2000, the only orthopoxvirus vaccine available in the United States at that time (3). During 2020-2021, ACIP considered evidence for use of JYNNEOS, a replication-deficient Vaccinia virus vaccine, as an alternative to ACAM2000. In November 2021, ACIP unanimously voted in favor of JYNNEOS as an alternative to ACAM2000 for primary vaccination and booster doses. With these recommendations for use of JYNNEOS, two vaccines (ACAM2000 and JYNNEOS) are now available and recommended for preexposure prophylaxis against orthopoxvirus infection among persons at risk for such exposures.

The mRNA-1273 (Moderna) COVID-19 vaccine is a lipid nanoparticle-encapsulated, nucleoside-modified mRNA vaccine encoding the stabilized prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. During December 2020, the vaccine was granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA), and the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for use among persons aged 18 years (1), which was adopted by CDC. During December 19, 2020-January 30, 2022, approximately 204 million doses of Moderna COVID-19 vaccine were administered in the United States (2) as a primary series of 2 intramuscular doses (100 g [0.5 mL] each) 4 weeks apart. On January 31, 2022, FDA approved a Biologics License Application (BLA) for use of the Moderna COVID-19 vaccine (Spikevax, ModernaTX, Inc.) in persons aged 18 years (3). On February 4, 2022, the ACIP COVID-19 Vaccines Work Group conclusions regarding recommendations for the use of the Moderna COVID-19 vaccine were presented to ACIP at a public meeting. The Work Group's deliberations were based on the Evidence to Recommendation (EtR) Framework,* which incorporates the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach() to rank evidence quality. In addition to initial clinical trial data, ACIP considered new information gathered in the 12 months since issuance of the interim recommendations, including additional follow-up time in the clinical trial, real-world vaccine effectiveness studies, and postauthorization vaccine safety monitoring. ACIP also considered comparisons of mRNA vaccine effectiveness and safety in real-world settings when first doses were administered 8 weeks apart instead of the original intervals used in clinical trials (3 weeks for BNT162b2 [Pfizer-BioNTech] COVID-19 vaccine and 4 weeks for Moderna COVID-19 vaccine). Based on this evidence, CDC has provided guidance that an 8-week interval might be optimal for some adolescents and adults. The additional information gathered since the issuance of the interim recommendations increased certainty that the benefits of preventing symptomatic and asymptomatic SARS-CoV-2 infection, hospitalization, and death outweigh vaccine-associated risks of the Moderna COVID-19 vaccine. On February 4, 2022, ACIP modified its interim recommendation to a standard recommendation() for use of the fully licensed Moderna COVID-19 vaccine in persons aged 18 years.

On December 19, 2019, the Food and Drug Administration (FDA) approved rVSVΔG-ZEBOV-GP Ebola vaccine (ERVEBO, Merck) for the prevention of Ebola virus disease (EVD) caused by infection with Ebola virus, species Zaire ebolavirus, in adults aged ≥18 years. In February 2020, the Advisory Committee on Immunization Practices (ACIP) recommended preexposure vaccination with ERVEBO for adults aged ≥18 years in the United States who are at highest risk for potential occupational exposure to Ebola virus because they are responding to an outbreak of EVD, work as health care personnel at federally designated Ebola treatment centers in the United States, or work as laboratorians or other staff members at biosafety level 4 facilities in the United States (1).

On February 27, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the adenovirus-vectored COVID-19 vaccine (Janssen Biotech, Inc., a Janssen Pharmaceutical company, Johnson & Johnson), and on February 28, 2021, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for its use as a single-dose primary vaccination in persons aged ≥18 years (1,2). On April 13, 2021, CDC and FDA recommended a pause in the use of Janssen COVID-19 vaccine after reports of thrombosis with thrombocytopenia syndrome (TTS), a rare condition characterized by low platelets and thrombosis, including at unusual sites such as the cerebral venous sinus (cerebral venous sinus thrombosis [CVST]), after receipt of the vaccine.* ACIP rapidly convened two emergency meetings to review reported cases of TTS, and 10 days after the pause commenced, ACIP reaffirmed its interim recommendation for use of the Janssen COVID-19 vaccine in persons aged ≥18 years, but included a warning regarding rare clotting events after vaccination, primarily among women aged 18-49 years (3). In July, after review of an updated benefit-risk assessment accounting for risks of Guillain-Barré syndrome (GBS) and TTS, ACIP concluded that benefits of vaccination with Janssen COVID-19 vaccine outweighed risks. Through ongoing safety surveillance and review of reports from the Vaccine Adverse Event Reporting System (VAERS), additional cases of TTS after receipt of Janssen COVID-19 vaccine, including deaths, were identified. On December 16, 2021, ACIP held an emergency meeting to review updated data on TTS and an updated benefit-risk assessment. At that meeting, ACIP made a recommendation for preferential use of mRNA COVID-19 vaccines over the Janssen COVID-19 vaccine, including both primary and booster doses administered to prevent COVID-19, for all persons aged ≥18 years. The Janssen COVID-19 vaccine may be considered in some situations, including for persons with a contraindication to receipt of mRNA COVID-19 vaccines.

Three COVID-19 vaccines are currently approved under a Biologics License Application (BLA) or authorized under an Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) and recommended for primary vaccination by the Advisory Committee on Immunization Practices (ACIP) in the United States: the 2-dose mRNA-based Pfizer-BioNTech/Comirnaty and Moderna COVID-19 vaccines and the single-dose adenovirus vector-based Janssen (Johnson & Johnson) COVID-19 vaccine (1,2) (Box 1). In August 2021, FDA amended the EUAs for the two mRNA COVID-19 vaccines to allow for an additional primary dose in certain immunocompromised recipients of an initial mRNA COVID-19 vaccination series (1). During September-October 2021, FDA amended the EUAs to allow for a COVID-19 vaccine booster dose following a primary mRNA COVID-19 vaccination series in certain recipients aged ≥18 years who are at increased risk for serious complications of COVID-19 or exposure to SARS-CoV-2 (the virus that causes COVID-19), as well as in recipients aged ≥18 years of Janssen COVID-19 vaccine (1) (Table). For the purposes of these recommendations, an additional primary (hereafter additional) dose refers to a dose of vaccine administered to persons who likely did not mount a protective immune response after initial vaccination. A booster dose refers to a dose of vaccine administered to enhance or restore protection by the primary vaccination, which might have waned over time. Health care professionals play a critical role in COVID-19 vaccination efforts, including for primary, additional, and booster vaccination, particularly to protect patients who are at increased risk for severe illness and death.

The Pfizer-BioNTech COVID-19 (BNT162b2) vaccine is a lipid nanoparticle-formulated, nucleoside-modified mRNA vaccine encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. On August 23, 2021, the Food and Drug Administration (FDA) approved a Biologics License Application (BLA) for use of the Pfizer-BioNTech COVID-19 vaccine, marketed as Comirnaty (Pfizer, Inc.), in persons aged ≥16 years (1). The Pfizer-BioNTech COVID-19 vaccine is also recommended for adolescents aged 12-15 years under an Emergency Use Authorization (EUA) (1). All persons aged ≥12 years are recommended to receive 2 doses (30 μg, 0.3 mL each), administered 3 weeks apart (2,3). As of November 2, 2021, approximately 248 million doses of the Pfizer-BioNTech COVID-19 vaccine had been administered to persons aged ≥12 years in the United States.* On October 29, 2021, FDA issued an EUA amendment for a new formulation of Pfizer-BioNTech COVID-19 vaccine for use in children aged 5-11 years, administered as 2 doses (10 μg, 0.2 mL each), 3 weeks apart (Table) (1). On November 2, 2021, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation(†) for use of the Pfizer-BioNTech COVID-19 vaccine in children aged 5-11 years for the prevention of COVID-19. To guide its deliberations regarding recommendations for the vaccine, ACIP used the Evidence to Recommendation (EtR) Framework(§) and incorporated a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.(¶) The ACIP recommendation for the use of the Pfizer-BioNTech COVID-19 vaccine in children aged 5-11 years under an EUA is interim and will be updated as additional information becomes available. The Pfizer-BioNTech COVID-19 vaccine has high efficacy (>90%) against COVID-19 in children aged 5-11 years, and ACIP determined benefits outweigh risks for vaccination. Vaccination is important to protect children against COVID-19 and reduce community transmission of SARS-CoV-2.

The Pfizer-BioNTech COVID-19 (BNT162b2) vaccine is a lipid nanoparticle-formulated, nucleoside-modified mRNA vaccine encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. Vaccination with the Pfizer-BioNTech COVID-19 vaccine consists of 2 intramuscular doses (30 μg, 0.3 mL each) administered 3 weeks apart. On December 11, 2020, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for use of the Pfizer-BioNTech COVID-19 vaccine (Pfizer, Inc; Philadelphia, Pennsylvania) in persons aged ≥16 years (1); on December 12, 2020, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for use of the vaccine in the same age group (2). As of May 12, 2021, approximately 141.6 million doses of the Pfizer-BioNTech COVID-19 vaccine had been administered to persons aged ≥16 years.* On May 10, 2021, FDA expanded the EUA for the Pfizer-BioNTech COVID-19 vaccine to include adolescents aged 12-15 years (1). On May 12, 2021, ACIP issued an interim recommendation(†) for use of the Pfizer-BioNTech COVID-19 vaccine in adolescents aged 12-15 years for the prevention of COVID-19. To guide its deliberations regarding the vaccine, ACIP used the Evidence to Recommendation (EtR) Framework,(§) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.(¶) The ACIP recommendation for the use of the Pfizer-BioNTech COVID-19 vaccine in persons aged ≥12 years under an EUA is interim and will be updated as additional information becomes available.

On February 27, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Janssen COVID-19 (Ad.26.COV2.S) vaccine (Janssen Biotech, Inc., a Janssen Pharmaceutical company, Johnson & Johnson; New Brunswick, New Jersey), and on February 28, 2021, the Advisory Committee on Immunization Practices (ACIP) issued interim recommendations for its use in persons aged ≥18 years (1,2). On April 13, 2021, CDC and FDA recommended a pause in the use of the Janssen COVID-19 vaccine after reports of six U.S. cases of cerebral venous sinus thrombosis (CVST) with thrombocytopenia, a rare thromboembolic syndrome, among Janssen COVID-19 vaccine recipients (3). Two emergency ACIP meetings were rapidly convened to review reported cases of thrombosis with thrombocytopenia syndrome (TTS) and to consider updated recommendations for use of the Janssen COVID-19 vaccine in the United States. On April 23, 2021, after a discussion of the benefits and risks of resuming vaccination, ACIP reaffirmed its interim recommendation for use of the Janssen COVID-19 vaccine in all persons aged ≥18 years under the FDA's EUA, which now includes a warning that rare clotting events might occur after vaccination, primarily among women aged 18-49 years. Patient and provider education about the risk for TTS with the Janssen COVID-19 vaccine, especially among women aged <50 years, as well as the availability of alternative COVID-19 vaccines, is required to guide vaccine decision-making and ensure early recognition and clinical management of TTS.

On February 27, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Janssen COVID-19 (Ad.26.COV2.S) vaccine (Janssen Biotech, Inc, a Janssen Pharmaceutical company, Johnson & Johnson; New Brunswick, New Jersey). The Janssen COVID-19 vaccine is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector vaccine, encoding the stabilized prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19 (1). Vaccination with the Janssen COVID-19 vaccine consists of a single dose (5 × 1010 virus particles per 0.5-mL dose) administered intramuscularly. On February 28, 2021, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation* for use of the Janssen COVID-19 vaccine in persons aged ≥18 years for the prevention of COVID-19. This vaccine is the third COVID-19 vaccine authorized under an EUA for the prevention of COVID-19 in the United States (2). To guide its deliberations regarding the vaccine, ACIP used the Evidence to Recommendations (EtR) framework,† following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.§ The ACIP recommendation for the use of the Janssen COVID-19 vaccine under an EUA is interim and will be updated as additional information becomes available.

This report summarizes the recommendations of the Advisory Committee on Immunization Practices (ACIP) for use of the rVSVΔG-ZEBOV-GP Ebola vaccine (Ervebo) in the United States. The vaccine contains rice-derived recombinant human serum albumin and live attenuated recombinant vesicular stomatitis virus (VSV) in which the gene encoding the glycoprotein of VSV was replaced with the gene encoding the glycoprotein of Ebola virus species Zaire ebolavirus. Persons with a history of severe allergic reaction (e.g., anaphylaxis) to rice protein should not receive Ervebo. This is the first and only vaccine currently licensed by the Food and Drug Administration for the prevention of Ebola virus disease (EVD). These guidelines will be updated based on availability of new data or as new vaccines are licensed to protect against EVD.ACIP recommends preexposure vaccination with Ervebo for adults aged ≥18 years in the U.S. population who are at highest risk for potential occupational exposure to Ebola virus species Zaire ebolavirus because they are responding to an outbreak of EVD, work as health care personnel at federally designated Ebola treatment centers in the United States, or work as laboratorians or other staff at biosafety level 4 facilities in the United States. Recommendations for use of Ervebo in additional populations at risk for exposure and other settings will be considered and discussed by ACIP in the future.

The first vaccines for prevention of coronavirus disease 2019 (COVID-19) in the United States were authorized for emergency use by the Food and Drug Administration (FDA) (1) and recommended by the Advisory Committee on Immunization Practices (ACIP) in December 2020.* However, demand for COVID-19 vaccines is expected to exceed supply during the first months of the national COVID-19 vaccination program. ACIP advises CDC on population groups and circumstances for vaccine use.(†) On December 1, ACIP recommended that 1) health care personnel(§) and 2) residents of long-term care facilities(¶) be offered COVID-19 vaccination first, in Phase 1a of the vaccination program (2). On December 20, 2020, ACIP recommended that in Phase 1b, vaccine should be offered to persons aged ≥75 years and frontline essential workers (non-health care workers), and that in Phase 1c, persons aged 65-74 years, persons aged 16-64 years with high-risk medical conditions, and essential workers not recommended for vaccination in Phase 1b should be offered vaccine.** These recommendations for phased allocation provide guidance for federal, state, and local jurisdictions while vaccine supply is limited. In its deliberations, ACIP considered scientific evidence regarding COVID-19 epidemiology, ethical principles, and vaccination program implementation considerations. ACIP's recommendations for COVID-19 vaccine allocation are interim and might be updated based on changes in conditions of FDA Emergency Use Authorization, FDA authorization for new COVID-19 vaccines, changes in vaccine supply, or changes in COVID-19 epidemiology.

On December 18, 2020, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Moderna COVID-19 (mRNA-1273) vaccine (ModernaTX, Inc; Cambridge, Massachusetts), a lipid nanoparticle-encapsulated, nucleoside-modified mRNA vaccine encoding the stabilized prefusion spike glycoprotein of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (1). This vaccine is the second COVID-19 vaccine authorized under an EUA for the prevention of COVID-19 in the United States (2). Vaccination with the Moderna COVID-19 vaccine consists of 2 doses (100 μg, 0.5 mL each) administered intramuscularly, 1 month (4 weeks) apart. On December 19, 2020, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation* for use of the Moderna COVID-19 vaccine in persons aged ≥18 years for the prevention of COVID-19. To guide its deliberations regarding the vaccine, ACIP employed the Evidence to Recommendation (EtR) Framework,(†) using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.(§) Use of all COVID-19 vaccines authorized under an EUA, including the Moderna COVID-19 vaccine, should be implemented in conjunction with ACIP's interim recommendations for allocating initial supplies of COVID-19 vaccines (3). The ACIP recommendation for the use of the Moderna COVID-19 vaccine under EUA is interim and will be updated as additional information becomes available.

On December 11, 2020, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Pfizer-BioNTech COVID-19 (BNT162b2) vaccine (Pfizer, Inc; Philadelphia, Pennsylvania), a lipid nanoparticle-formulated, nucleoside-modified mRNA vaccine encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (1). Vaccination with the Pfizer-BioNTech COVID-19 vaccine consists of 2 doses (30 μg, 0.3 mL each) administered intramuscularly, 3 weeks apart. On December 12, 2020, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation* for use of the Pfizer-BioNTech COVID-19 vaccine in persons aged ≥16 years for the prevention of COVID-19. To guide its deliberations regarding the vaccine, ACIP employed the Evidence to Recommendation (EtR) Framework,(†) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.(§) The recommendation for the Pfizer-BioNTech COVID-19 vaccine should be implemented in conjunction with ACIP's interim recommendation for allocating initial supplies of COVID-19 vaccines (2). The ACIP recommendation for the use of the Pfizer-BioNTech COVID-19 vaccine under EUA is interim and will be updated as additional information becomes available.

The emergence of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), has led to a global pandemic that has disrupted all sectors of society. Less than 1 year after the SARS-CoV-2 genome was first sequenced, an application* for Emergency Use Authorization for a candidate vaccine has been filed with the Food and Drug Administration (FDA). However, even if one or more vaccine candidates receive authorization for emergency use, demand for COVID-19 vaccine is expected to exceed supply during the first months of the national vaccination program. The Advisory Committee on Immunization Practices (ACIP) advises CDC on population groups and circumstances for vaccine use.(†) ACIP convened on December 1, 2020, in advance of the completion of FDA's review of the Emergency Use Authorization application, to provide interim guidance to federal, state, and local jurisdictions on allocation of initial doses of COVID-19 vaccine. ACIP recommended that, when a COVID-19 vaccine is authorized by FDA and recommended by ACIP, both 1) health care personnel(§) and 2) residents of long-term care facilities (LTCFs)(¶) be offered vaccination in the initial phase of the COVID-19 vaccination program (Phase 1a**).(††) In its deliberations, ACIP considered scientific evidence of SARS-CoV-2 epidemiology, vaccination program implementation, and ethical principles.(§§) The interim recommendation might be updated over the coming weeks based on additional safety and efficacy data from phase III clinical trials and conditions of FDA Emergency Use Authorization.

To reduce the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) and its associated impacts on health and society, COVID-19 vaccines are essential. The U.S. government is working to produce and deliver safe and effective COVID-19 vaccines for the entire U.S. population. The Advisory Committee on Immunization Practices (ACIP)* has broadly outlined its approach for developing recommendations for the use of each COVID-19 vaccine authorized or approved by the Food and Drug Administration (FDA) for Emergency Use Authorization or licensure (1). ACIP's recommendation process includes an explicit and transparent evidence-based method for assessing a vaccine's safety and efficacy as well as consideration of other factors, including implementation (2). Because the initial supply of vaccine will likely be limited, ACIP will also recommend which groups should receive the earliest allocations of vaccine. The ACIP COVID-19 Vaccines Work Group and consultants with expertise in ethics and health equity considered external expert committee reports and published literature and deliberated the ethical issues associated with COVID-19 vaccine allocation decisions. The purpose of this report is to describe the four ethical principles that will assist ACIP in formulating recommendations for the allocation of COVID-19 vaccine while supply is limited, in addition to scientific data and implementation feasibility: 1) maximize benefits and minimize harms; 2) promote justice; 3) mitigate health inequities; and 4) promote transparency. These principles can also aid state, tribal, local, and territorial public health authorities as they develop vaccine implementation strategies within their own communities based on ACIP recommendations.

During 2014-2016, CDC, working with U.S. and international partners, mounted a concerted response to end the unprecedented epidemic of Ebola virus disease (Ebola) in West Africa. CDC's response, which was the largest in the agency's history, was directed simultaneously at controlling the epidemic in West Africa and strengthening preparedness for Ebola in the United States. Although experience in responding to approximately 20 Ebola outbreaks since 1976 had provided CDC and other international responders an understanding of the disease and how to stop its spread, the epidemic in West Africa presented new and formidable challenges. The initial response was slow and complicated for several reasons, including wide geographic spread of cases, poor public health and societal infrastructure, sociodemographic factors, local unfamiliarity with Ebola, and distrust of government and health care workers. In the United States, widespread public alarm erupted after Ebola cases were diagnosed in Dallas, Texas, and New York City, New York. CDC, in collaboration with its U.S. and international counterparts, applied proven public health strategies as well as innovative new approaches to help control the Ebola epidemic in West Africa and strengthen public health readiness in the United States. Lessons learned include the recognition that West African and other countries need effective systems to detect and stop infectious disease threats, the need for stronger international surge capacity for times when countries are overwhelmed by an outbreak, and the importance of improving infection prevention and control in health care settings. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

In response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC prepared for the potential introduction of Ebola into the United States. The immediate goals were to rapidly identify and isolate any cases of Ebola, prevent transmission, and promote timely treatment of affected patients. CDC's technical expertise and the collaboration of multiple partners in state, local, and municipal public health departments; health care facilities; emergency medical services; and U.S. government agencies were essential to the domestic preparedness and response to the Ebola epidemic and relied on longstanding partnerships. CDC established a comprehensive response that included two new strategies: 1) active monitoring of travelers arriving from countries affected by Ebola and other persons at risk for Ebola and 2) a tiered system of hospital facility preparedness that enabled prioritization of training. CDC rapidly deployed a diagnostic assay for Ebola virus (EBOV) to public health laboratories. Guidance was developed to assist in evaluation of patients possibly infected with EBOV, for appropriate infection control, to support emergency responders, and for handling of infectious waste. CDC rapid response teams were formed to provide assistance within 24 hours to a health care facility managing a patient with Ebola. As a result of the collaborations to rapidly identify, isolate, and manage Ebola patients and the extensive preparations to prevent spread of EBOV, the United States is now better prepared to address the next global infectious disease threat.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Public health focus is now on Zika virus, a mosquito-borne flavivirus that emerged in the Americas in 2015 with new intensity and alarming potential sequelae, after circulating in Africa and Southeast Asia for decades with rare reports of outbreaks and no recognized serious adverse outcomes. Paralleling the rapid spread of chikungunya in the Americas in 2013,1 Zika virus has affected many of the same areas since its arrival in Brazil in early 2015.2 By February 26, 2016, local transmission had been reported from 31 countries and territories in the Americas, with concomitant outbreaks in Cape Verde and the Pacific Islands.3 In the United States, as of March 2, 2016, 153 cases, all travel associated, have been reported to ArboNet from 28 states and the District of Columbia; among the 108 cases reported to ArboNet from US territories, all but 1 have been locally acquired, with most cases reported from Puerto Rico (http://www.cdc.gov/zika/geo/united-states.html). Further spread throughout tropical areas in the Americas is likely. For most individuals, the Zika virus infection is associated with mild and self-limited clinical symptoms, but it is increasingly being linked to prenatal impacts, most notably congenital microcephaly.4–6 Better understanding of this arboviral disease, including the epidemiology, clinical outcomes, nonmosquito modes of transmission, immune response, pathophysiology, and clinical course, is critically needed. The systematic review by Paixão et al.7 of 52 studies on Zika virus in this issue of AJPH yields valuable information in these areas that can help guide prevention and control efforts.

Since Ebola virus was first identified in 1976, no previous Ebola outbreak has been as large or persistent as the current epidemic, and none has spread beyond East and Central Africa. To date, more than 1000 people, including numerous health care workers, have been killed by Ebola virus disease (EVD) in 2014, and the number of cases in the current outbreak now exceeds the number from all previous outbreaks combined. Indirect effects include disruption of standard medical care, including for common and deadly conditions such as malaria, and substantial economic losses, insecurity, and social disruption in countries that were already struggling to recover from decades of war.

In the USA, infectious diseases continue to exact a substantial toll on health and health-care resources. Endemic diseases such as chronic hepatitis, HIV, and other sexually transmitted infections affect millions of individuals and widen health disparities. Additional concerns include health-care-associated and foodborne infections-both of which have been targets of broad prevention efforts, with success in some areas, yet major challenges remain. Although substantial progress in reduction of the burden of vaccine-preventable diseases has been made, continued cases and outbreaks of these diseases persist, driven by various contributing factors. Worldwide, emerging and reemerging infections continue to challenge prevention and control strategies while the growing problem of antimicrobial resistance needs urgent action. An important priority for control of infectious disease is to ensure that scientific and technological advances in molecular diagnostics and bioinformatics are well integrated into public health. Broad and diverse partnerships across governments, health care, academia, and industry, and with the public, are essential to effectively reduce the burden of infectious diseases.

The outbreak of invasive fungal infections among patients who received injections of contaminated methylprednisolone acetate prepared by the New England Compounding Center (in Framingham, Massachusetts) is a disturbing tragedy, already the largest health care–associated fungal outbreak reported in the United States, with 693 cases and 45 deaths reported as of January 28, 2013.1 Effectively responding to this catastrophic event required rapid actions by clinical and public health practitioners who worked to ensure discontinued use of the suspect medication, notify at-risk patients and their physicians, and decipher the many unknowns about the outbreak to provide the best guidance for minimizing harm. | In the United States, public health is a distributed system, with critical responsibilities at local, state, and federal levels. The fungal infections outbreak underscores the pivotal detection and response roles of state health departments, working with local clinical and public health colleagues. In this outbreak, the Tennessee Department of Health (TDOH) sounded the alarm based on a telephone call from an alert clinician treating a patient with an unusual form of meningitis.2 The clinician had not only asked about a broad range of possible patient exposures, but also recognized the potential public health implications and knew to contact the health department. This well-established linkage reflects long-term efforts of the TDOH to establish partnerships and work collaboratively with clinicians, hospitals, and other health care facilities to implement measures to reduce health care–associated infections.

BACKGROUND: In April 2009, a novel influenza A virus emerged in the United States. By the end of July, influenza A (H1N1) 2009 monovalent (2009 H1N1) vaccine had been developed, licensed, and recommended by the Advisory Committee on Immunization Practices. Initial target groups for vaccination were identified and the first vaccine was publicly available in early October 2009. OBJECTIVE: This study examines socio-demographic differences in opinions about 2009 pandemic influenza A (H1N1) (pH1N1) and seasonal influenza disease and vaccines and the association with receipt of influenza vaccinations during the 2009-2010 influenza season. Changes in opinions over the course of the pH1N1 pandemic were also examined. METHODS: Data from the 2009 National H1N1 Flu Survey (NHFS) were analyzed. The NHFS was a CDC-sponsored telephone survey initiated in response to the 2009 pH1N1 pandemic to obtain weekly within-season estimates of vaccination coverage, opinions, and other information. RESULTS: Opinions about influenza vaccine and disease varied significantly by race/ethnicity, income, and education level. In multivariable logistic regression analysis, adjusted 2009 H1N1 vaccination coverage was most strongly associated with opinions about the effectiveness of the vaccine and personal risk of disease, varying from 7 to 11% among adults who believed the vaccine to have low effectiveness and themselves at low risk of influenza, to 50-53% among those who thought vaccine effectiveness to be high and themselves at high risk of influenza. CONCLUSION: Improving communication about personal risk and the effectiveness of influenza vaccines may improve vaccination coverage. The findings of difference in opinions could be used to target communication.

BACKGROUND: Hepatitis A outbreaks are well documented among men who have sex with men (MSM). This analysis examines characteristics associated with hepatitis A virus (HAV) infection among a large group of young adult MSM from five USA cities. METHODS: The Young Men's Survey was a cross-sectional prevalence study of HIV infection and related behavioural risk factors among MSM aged 15-29 years during 1994-2000. Serum specimens from HIV-negative participants were retrospectively tested for antibodies to HAV (anti-HAV). Data were stratified by ethnicity and analysed with logistic regression. RESULTS: Overall anti-HAV prevalence was 18.4% among the 2708 participants, and varied by ethnicity from 6.9 to 45.3% and was highest among Hispanic and Asian men (P < 0.001). Prevalence increased with age across all racial/ethnic groups. Among white men, anti-HAV positivity was associated with having 20 or more lifetime male sex partners for those aged 15-22 years (adjusted odds ratio (AOR)=2.1, 95% confidence interval (CI)=1.0-4.1) and ever having had unprotected anal sex for those aged 23-29 years (AOR=2.4, 95% CI=1.2-4.5). CONCLUSIONS: Factors associated with a history of HAV infection among MSM in non-outbreak settings are probably similar to those among non-MSM. MSM are still at risk for HAV infection as a result of outbreaks occurring in MSM communities. Additional studies of hepatitis A vaccination coverage are needed to determine if strategies to vaccinate MSM are adequate.

OBJECTIVES: We described seroprevalence of antibody to hepatitis A virus (anti-HAV) in the United States during 1999-2006 and compared it with seroprevalence before the availability of vaccine. METHODS: We analyzed data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (NHANES) to obtain estimates of anti-HAV seroprevalence for the U.S. household population. We grouped region of residence based on the 1999 Advisory Committee on Immunization Practices recommendations into 17 states with any recommendation (vaccinating) and 33 states without any recommendation (non-vaccinating). RESULTS: During 1999-2006, the overall seroprevalence of anti-HAV was 34.9% (95% confidence interval [CI] 33.1, 36.7). During 1999-2006, U.S.-born children living in vaccinating states (33.8%, 95% CI 26.2, 42.2) had a higher seroprevalence than children in non-vaccinating states (11.0%, 95% CI 9.4, 12.8; p < 0.001). Seroprevalence among children increased from 8.0% (95% CI 6.3, 10.1) during 1988-1994 to 20.2% (95% CI 16.0, 24.8) during 1999-2006 (p < 0.001). For U.S.-born children aged 6-19 years, the strongest factor associated with seroprevalence was residence in vaccinating states. Among U.S.-born adults aged > 19 years, the overall age-adjusted seroprevalence of anti-HAV was 29.9% (95% CI 28.3, 31.5) during 1999-2006, which was not significantly different from the seroprevalence during 1988-1994 (32.2%, 95% CI 30.1, 34.4). CONCLUSIONS: Increases in seroprevalence among children in vaccinating states suggest a positive effect of the 1999 vaccination recommendations.