BACKGROUND: In the United States, 2 doses of measles-mumps-rubella (MMR)-containing vaccines are recommended routinely during childhood; a third dose may be given under certain circumstances. We present observed seroprotection rates and estimate long-term dynamics of measles, mumps, and rubella neutralizing antibody (nAb) levels among 2- and 3-dose MMR (MMR2 and MMR3, respectively) vaccinees. METHODS: Persons who received MMR2 at age 4-12 years or MMR3 at age 18-31 years were enrolled in 1994-1995 and 2009-2010, respectively. Per cohort, sera were collected before vaccination (baseline) and at various intervals ranging from 1 month to 10 years postvaccination to assess nAb levels. Annual changes in nAb levels per virus and cohort were estimated through 10 years postvaccination using generalized estimating equations. Models were stratified by baseline nAb levels. RESULTS: Among MMR2 participants (n = 621), 93.7%, 73.4%, and 83.9% had protective nAb levels against measles, mumps, and rubella, respectively, at the 10-year visit; among MMR3 participants (n = 665), 90.5%, 69.1%, and 100% had protective nAb levels, respectively, at the 9-11-year visit. Estimated nAb levels declined annually across both cohorts, all viruses, and baseline nAb strata, though patterns and magnitude varied. More than one-quarter of participants had mumps nAb levels below the presumed seroprotection threshold at the terminal visits. CONCLUSIONS: These findings indicate that even when MMR antibodies wane, protection against disease is largely retained. Waning of mumps antibodies was greater than for measles and rubella in both 2- and 3-dose vaccinees, likely because a greater proportion failed to mount a robust initial response.

Long-term effects of COVID-19 on multiple organ systems have been reported. Indigenous persons experienced disproportionate morbidity and mortality from COVID-19; however, Post-COVID-19 Conditions (PCC) have not been well described in this population. We conducted a longitudinal cohort study among Indigenous persons living in the Navajo Nation or White Mountain Apache Tribal lands in the Southwest United States who tested positive for SARS-CoV-2 between February 1, 2021 and August 31, 2022. Participants were enrolled during their acute illness and followed for three months. PCC was defined as the presence of any self-reported symptom and/or any sequelae or new condition recorded in the electronic health record at the 3-month visit. Risk factors for PCC were evaluated using Poisson regression with robust standard errors. The analysis included 258 adults and 84 children. Most participants (98.4% of adults, 90.5% of children) experienced a mild, symptomatic acute illness. Over half of adults (57.8%) and a third (39.3%) of children experienced six or more symptoms during the acute illness. Three months post-acute COVID-19, 39.8% of adults and 15.9% of children had symptoms consistent with PCC. Commonly reported symptoms were fatigue/tiredness, cough, headache, runny nose, and myalgia. Among adults enrolled during Omicron predominance, older age and hospitalization for COVID-19 were significantly associated with an increased risk of PCC, and COVID-19 vaccination was significantly associated with a decreased risk of PCC in univariable analysis. In a multivariable analysis, COVID-19 vaccination (risk ratio: 0.56; 95% confidence interval: 0.34, 0.90) remained significantly associated with a decreased risk of PCC. In this cohort of Indigenous persons in the Southwest US, PCC at three months post-acute COVID-19 illness were common, including among individuals with mild acute illness. While the absence of a control group is a limitation, these findings highlight the potential ongoing healthcare needs related to PCC in Indigenous populations.

CONTEXT: Congenital cytomegalovirus (cCMV) infection is the most common infectious cause of birth defects and the leading non-genetic cause of sensorineural hearing loss in the United States. Prior national cCMV infection prevalence estimates were based on one multi-site screening study conducted between 2007 and 2012 and were not adjusted for sociodemographic characteristics, such as maternal race and ethnicity or age. OBJECTIVE: This study sought to estimate national and state-specific prevalence of cCMV infection in the United States, adjusted for maternal race and ethnicity and maternal age group, by pooling estimates from published studies. DESIGN: We searched PubMed for U.S. cCMV newborn screening studies conducted between 2003 and 2023. From included studies, we abstracted maternal race and ethnicity- and age group-stratified cCMV prevalence to estimate strata-specific pooled prevalence. We obtained strata-specific weights from live birth data. MAIN OUTCOME MEASURE: Estimated adjusted national and state-specific prevalence estimates from 2018 to 2022. RESULTS: Four studies (conducted 2004-2005, 2008, 2007-2012, and 2016-2021) were included for data abstraction. Overall, infants born to non-Hispanic Black (9.3 [8.2-10.5] per 1000) or non-Hispanic American Indian and Alaska Native (8.5 [2.1-33.2] per 1000) mothers had the highest cCMV prevalence. The estimated race and ethnicity-adjusted prevalence was 4.6-4.7 per 1000 live births nationally and ranged from 3.9 to 6.5 per 1000 across states from 2018 to 2022. Southern states and Alaska consistently had the highest cCMV prevalence. The estimated maternal age group-adjusted prevalence was 4.3-4.4 per 1000 live births nationally and ranged from 3.8 to 5.1 per 1000 across states from 2018 to 2022. CONCLUSIONS: States with larger proportions of racial and ethnic minorities had higher estimated prevalence of cCMV infection compared to states with larger proportions of White persons. These estimates may be useful for informing cCMV surveillance at the jurisdiction level and developing tailored, culturally relevant education and prevention strategies for persons at higher risk.

Measles, a highly contagious respiratory virus with the potential to cause severe complications, hospitalization, and death, was declared eliminated from the United States in 2000; however, with ongoing global transmission, infections in the United States still occur. On March 7, 2024, the Chicago Department of Public Health (CDPH) confirmed a case of measles in a male aged 1 year residing in a temporary shelter for migrants in Chicago. Given the congregate nature of the setting, high transmissibility of measles, and low measles vaccination coverage among shelter residents, measles virus had the potential to spread rapidly among approximately 2,100 presumed exposed shelter residents. CDPH immediately instituted outbreak investigation and response activities in collaboration with state and local health departments, health care facilities, city agencies, and shelters. On March 8, CDPH implemented active case-finding and coordinated a mass vaccination campaign at the affected shelter (shelter A), including vaccinating 882 residents and verifying previous vaccination for 784 residents over 3 days. These activities resulted in 93% measles vaccination coverage (defined as receipt of ≥1 recorded measles vaccine dose) by March 11. By May 13, a total of 57 confirmed measles cases associated with residing in or having contact with persons from shelter A had been reported. Most cases (41; 72%) were among persons who did not have documentation of measles vaccination and were considered unvaccinated. In addition, 16 cases of measles occurred among persons who had received ≥1 measles vaccine dose ≥21 days before first known exposure. This outbreak underscores the need to ensure high vaccination coverage among communities residing in congregate settings.

BACKGROUND: Despite the disproportionate morbidity and mortality expeHealth Equity and Health Disparitiesrienced by American Indian and Alaska Native (AI/AN) persons during the coronavirus disease 2019 (COVID-19) pandemic, few studies have reported vaccine effectiveness (VE) estimates among these communities. METHODS: We conducted a test-negative case-control analysis among AI/AN persons aged ≥12 years presenting for care from January 1, 2021, through November 30, 2021, to evaluate the effectiveness of mRNA COVID-19 vaccines against COVID-19-associated outpatient visits and hospitalizations. Cases and controls were patients with ≥1 symptom consistent with COVID-19-like illness; cases were defined as those test-positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and controls were defined as those test-negative for SARS-CoV-2. We used unconditional multivariable logistic regression to estimate VE, defined as 1 minus the adjusted odds ratio for vaccination among cases vs controls. RESULTS: The analysis included 207 cases and 267 test-negative controls. Forty-four percent of cases and 78% of controls received 2 doses of either BNT162b2 or mRNA-1273 vaccine. VE point estimates for 2 doses of mRNA vaccine were higher for hospitalized participants (94.6%; 95% CI, 88.0-97.6) than outpatient participants (86.5%; 95% CI, 63.0-95.0), but confidence intervals overlapped. CONCLUSIONS: Among AI/AN persons, mRNA COVID-19 vaccines were highly effective in preventing COVID-associated outpatient visits and hospitalizations. Maintaining high vaccine coverage, including booster doses, will reduce the burden of disease in this population.

BACKGROUND: During the 2009 influenza A(H1N1)pdm09 pandemic, 77 countries received donated monovalent A(H1N1)pdm09 vaccine through the WHO Pandemic Influenza A(H1N1) Vaccine Deployment Initiative. However, 47% did not receive their first shipment until after the first wave of virus circulation, and 8% did not receive their first shipment until after the WHO declared the end of the pandemic. Arguably, these shipments were too late into the pandemic to have a substantial effect on virus transmission or disease burden during the first waves of the pandemic. OBJECTIVES: In order to evaluate the potential benefits of earlier vaccine availability, we estimated the number of illnesses and deaths that could be averted during a 2009-like influenza pandemic under five different vaccine-availability timing scenarios. METHODS: We adapted a model originally developed to estimate annual influenza morbidity and mortality burden averted through US seasonal vaccination and ran it for five vaccine availability timing scenarios in nine low- and middle-income countries that received donated vaccine. RESULTS: Among nine study countries, we estimated that the number of averted cases was 61-216,197 for actual vaccine receipt, increasing to 2,914-283,916 had vaccine been available simultaneously with the United States. CONCLUSIONS: Earlier delivery of vaccines can reduce influenza case counts during a simulated 2009-like pandemic in some low- and middle-income countries. For others, increasing the number of cases and deaths prevented through vaccination may be dependent on factors other than timely initiation of vaccine administration, such as distribution and administration capacity.

The revised Standards for Adult Immunization Practice ("Standards"), published in 2014, recommend routine vaccination assessment, strong provider recommendation, vaccine administration or referral, and documentation of vaccines administered into immunization information systems (IIS). We assessed clinician and pharmacist implementation of the Standards in the United States from 2016 to 2018. Participating clinicians (family and internal medicine physicians, obstetricians-gynecologists, specialty physicians, physician assistants, and nurse practitioners) and pharmacists responded using an internet panel survey. Weighted proportion of clinicians and pharmacists reporting full implementation of each component of the Standards were calculated. Adjusted prevalence ratio (APR) estimates of practice characteristics associated with self-reported implementation of the Standards are also presented. Across all medical specialties, the percentages of clinicians and pharmacists implementing the vaccine assessment and recommendation components of the Standards were >80.0%. However, due to low IIS documentation, full implementation of the Standards was low overall, ranging from 30.4% for specialty medicine to 45.8% in family medicine clinicians. The presence of an immunization champion (APR, 1.40 [95% confidence interval {CI}, 1.26 to 1.54]), use of standing orders (APR, 1.41 [95% CI, 1.27 to 1.57]), and use of a patient reminder-recall system (APR, 1.39 [95% CI, 1.26 to 1.54]) were positively associated with adherence to the Standards by clinicians. Similar results were observed for pharmacists. Nonetheless, vaccination improvement strategies, i.e., having standing orders in place, empowering an immunization champion, and using patient recall-reminder systems were underutilized in clinical settings; full implementation of the Standards was inconsistent across all health care provider practices.

BACKGROUND: Annual vaccination against seasonal influenza is widely recognized as the primary intervention method in preventing morbidity and mortality from influenza, but coverage among adults is suboptimal in the United States. Safety and effectiveness perceptions regarding vaccines are consistently cited as factors that influence adults' decisions to accept or reject vaccination. Therefore, we conducted this analysis in order to understand sociodemographic, attitude, and knowledge factors associated with these perceptions for influenza vaccine among adults in three different age groups. METHODS: Probability-based Internet panel surveys using nationally representative samples of adults aged >/=19 years in the United States were conducted during February-March of 2017 and 2018. We asked respondents if they believed the influenza vaccine was safe and effective. We calculated prevalence ratios using chi-square and pairwise t-tests to determine associations between safety and effectiveness beliefs and sociodemographic variables for adults aged 19-49, 50-64, and >/=65 years. RESULTS: Survey completion rates were 58.2% (2017) and 57.2% (2018); we analyzed 4597 combined responses. Overall, most adults reported the influenza vaccine was safe (86.3%) and effective (73.0%). However, fewer younger adults reported positive perceptions compared with older age groups. Respondents who believed the vaccine was safe also reported it was effective. CONCLUSIONS: Generally, adults perceived the influenza vaccine as safe and effective. Considering this, any improvements to these perceptions would likely be minor and have a limited effect on coverage. Future research to understand why, despite positive perceptions, adults are still choosing to forego the vaccine may be informative.

BACKGROUND: Infectious disease forecasting aims to predict characteristics of both seasonal epidemics and future pandemics. Accurate and timely infectious disease forecasts could aid public health responses by informing key preparation and mitigation efforts. MAIN BODY: For forecasts to be fully integrated into public health decision-making, federal, state, and local officials must understand how forecasts were made, how to interpret forecasts, and how well the forecasts have performed in the past. Since the 2013-14 influenza season, the Influenza Division at the Centers for Disease Control and Prevention (CDC) has hosted collaborative challenges to forecast the timing, intensity, and short-term trajectory of influenza-like illness in the United States. Additional efforts to advance forecasting science have included influenza initiatives focused on state-level and hospitalization forecasts, as well as other infectious diseases. Using CDC influenza forecasting challenges as an example, this paper provides an overview of infectious disease forecasting; applications of forecasting to public health; and current work to develop best practices for forecast methodology, applications, and communication. CONCLUSIONS: These efforts, along with other infectious disease forecasting initiatives, can foster the continued advancement of forecasting science.

BACKGROUND: Pneumococcus is a leading cause of pneumonia and meningitis. Zambia introduced a 10-valent pneumococcal conjugate vaccine (PCV10) in July 2013 using a 3-dose primary series at ages 6, 10, and 14 weeks with no booster. We evaluated the impact of PCV10 on meningitis and pneumonia hospitalizations. METHODS: Using hospitalization data from first-level care hospitals, available at the Ministry of Health, and from the largest pediatric referral hospital in Lusaka, we identified children aged <5 years who were hospitalized with pneumonia or meningitis from January 2010-December 2016. We used time-series analyses to measure the effect of PCV10 on monthly case counts by outcome and age group (<1 year, 1-4 years), accounting for seasonality. We defined the pre- and post-PCV10 periods as January 2010-June 2013 and July 2014-December 2016, respectively. RESULTS: At first-level care hospitals, pneumonia and meningitis hospitalizations among children aged <5 years accounted for 108 884 and 1742 admissions in the 42 months pre-PCV10, respectively, and 44 715 and 646 admissions in the 30 months post-PCV10, respectively. Pneumonia hospitalizations declined by 37.8% (95% confidence interval [CI] 21.4-50.3%) and 28.8% (95% CI 17.7-38.7%) among children aged <1 year and 1-4 years, respectively, while meningitis hospitalizations declined by 72.1% (95% CI 63.2-79.0%) and 61.6% (95% CI 50.4-70.8%), respectively, in these age groups. In contrast, at the referral hospital, pneumonia hospitalizations remained stable and a smaller but significant decline in meningitis was observed among children aged 1-4 years (39.3%, 95% CI 16.2-57.5%). CONCLUSIONS: PCV10 introduction was associated with declines in meningitis and pneumonia hospitalizations in Zambia, especially in first-level care hospitals.

BACKGROUND: The Advisory Committee for Immunization Practices recommends that all pregnant women receive the seasonal influenza vaccine and the tetanus toxoid, diphtheria toxoid, and acellular pertussis (Tdap) vaccine during every pregnancy. However, vaccination coverage rates are suboptimal among pregnant women in the United States, leaving these women and their unborn children at risk of vaccine-preventable diseases and their complications. OBJECTIVES: We sought to understand the current landscape of published literature regarding maternal immunization, including barriers to and predictors of vaccine acceptance, and identify gaps in the research in order to inform strategies for future programmatic improvement. METHODS: We conducted a literature search using MEDLINE (OVID), PsychINFO, and CINAHL (Ebsco) databases. The search included published, English-language manuscripts that identified patient, provider, or system-level barriers to, predictors of, or interventions that improved uptake of maternal vaccines among pregnant women in the US. Studies were reviewed using an inductive thematic analysis approach. RESULTS: We included 75 studies in our review. Pregnant women identified 25 different barriers to accepting recommended maternal immunizations; barriers related to vaccine safety perceptions were the most common. Healthcare providers identified 24 different barriers to vaccinating their pregnant patients. The most commonly cited barriers among healthcare providers were financial concerns. Eighteen different predictors of vaccine acceptance were identified. Receipt of a healthcare provider's recommendation was the factor most frequently reported as a reason for vaccination among pregnant women. CONCLUSIONS: We were able to identify gaps in the literature regarding maternal immunization and make recommendations for future research. Efforts to address the challenges of maternal immunization in the United States should include increasing the focus on Tdap, implementing more high-level assessments of safety perceptions and associated concerns, and determining most effective interventions.

BACKGROUND: The Standards for Adult Immunization Practice (Standards), revised in 2014, emphasize that adult-care providers assess vaccination status of adult patients at every visit, recommend vaccination, administer needed vaccines or refer to a vaccinating provider, and document vaccinations administered in state/local immunization information systems (IIS). Providers report numerous systems- and provider-level barriers to vaccinating adults, such as billing, payment issues, lower prioritization of vaccines due to competing demands, and lack of information about the use and utility of IIS. Barriers to vaccination result in missed opportunities to vaccinate adults and contribute to low vaccination coverage. Clinicians' (physicians, physician assistants, nurse practitioners) and pharmacists' reported barriers to assessment, recommendation, administration, referral, and documentation, provider vaccination practices, and perceptions regarding their adult patients' attitudes toward vaccines were evaluated. METHODS: Data from non-probability-based Internet panel surveys of U.S. clinicians (n=1714) and pharmacists (n=261) conducted in February-March 2017 were analyzed using SUDAAN. Weighted proportion of reported barriers to assessment, recommendation, administration, referral, and documentation in IIS were calculated. RESULTS: High percentages (70.0%-97.4%) of clinicians and pharmacists reported they routinely assessed, recommended, administered, and/or referred adults for vaccination. Among those who administered vaccines, 31.6% clinicians' and 38.4% pharmacists' submitted records to IIS. Reported barriers included: (a) assessment barriers: vaccination of adults is not within their scope of practice, inadequate reimbursement for vaccinations; (b) administration barriers: lack of staff to manage/administer vaccines, absence of necessary vaccine storage and handling equipment and provisions; and (c) documentation barriers: unaware if state/city has IIS that includes adults or not sure how their electronic system would link to IIS. CONCLUSION: Although many clinicians and pharmacists reported implementing most of the individual components of the Standards, with the exception of IIS use, there are discrepancies in providers' reported actual practices and their beliefs/perceptions, and barriers to vaccinating adults remain.

INTRODUCTION: Despite the proven effectiveness of immunization in preventing morbidity and mortality, adult vaccines remain underutilized. The objective of this study was to describe clinicians' and pharmacists' self-reported implementation of the Standards for Adult Immunization Practice ("the Standards"; i.e., routine assessment, recommendation, and administration/referral for needed vaccines, and documentation of administered vaccines, including in immunization information systems). METHODS: Two Internet panel surveys (one among clinicians and one among pharmacists) were conducted during February-March 2017 and asked respondents about their practice's implementation of the Standards. T-tests assessed associations between clinician medical specialty, vaccine type, and each component of the Standards (March-August 2017). RESULTS: Implementation of the Standards varied substantially by vaccine and provider type. For example, >80.0% of providers, including obstetrician/gynecologists and subspecialists, assessed for and recommended influenza vaccine. However, 24.3% of obstetrician/gynecologists and 48.9% of subspecialists did not stock influenza vaccine for administration. Although zoster vaccine was recommended by >89.0% of primary care providers, <58.0% stocked the vaccine; by contrast, 91.6% of pharmacists stocked zoster vaccine. Vaccine needs assessments, recommendations, and stocking/referrals also varied by provider type for pneumococcal; tetanus, diphtheria, acellular pertussis; tetanus diphtheria; human papillomavirus; and hepatitis B vaccines. CONCLUSIONS: This report highlights gaps in access to vaccines recommended for adults across the spectrum of provider specialties. Greater implementation of the Standards by all providers could improve adult vaccination rates in the U.S. by reducing missed opportunities to recommend vaccinations and either vaccinate or refer patients to vaccine providers.