BACKGROUND: To generate COVID-19 vaccine safety data in Nigeria, passive reporting was supplemented with cohort event monitoring (CEM), an active surveillance system. We described reactogenicity within 7 days and adverse events up to 3 months after each AstraZeneca or Moderna COVID-19 vaccine dose while assessing the feasibility of implementing CEM in a low- to middle-income country (LMIC) during a mass vaccination campaign. METHODS: Participants were aged ≥18 years with access to mobile phones who received the first dose of an authorized COVID-19 vaccine from participating health facilities in 6 states of Nigeria during September and October 2021. Data collectors interviewed participants via phone on days 0, 3, 7, and thereafter every 7 days for 3 months. The same schedule was restarted if a participant received a second vaccine dose. Proportions of participant-reported adverse events following COVID-19 vaccine receipt were calculated. Investigation and causality assessment were conducted on deaths using the World Health Organization causality guidelines. RESULTS: We enrolled 12,317 participants (AstraZeneca 6990; Moderna 5327); 6167/6990 (88.2 %) AstraZeneca and 4879/5327 (91.6 %) Moderna recipients completed a follow-up interview days 0-7 after the first dose; among them, 2685/6167 (43.5 %) AstraZeneca and 3533/4879 (72.4 %) Moderna recipients reported local reactions and 2456/6167 (39.8 %) AstraZeneca and 2087/4879 (42.8 %) Moderna recipients reported systemic reactions. Overall, 3891/6990 (55.7 %) AstraZeneca and 3978/5327 (72.8 %) Moderna recipients received a second dose of COVID-19 vaccine, among whom 897/3891 (23 %) AstraZeneca and 1979/3978 (49.7 %) Moderna recipients reported local reactions and 727/3891 (18.7 %) AstraZeneca and 1680/3978 (42.2 %) Moderna recipients reported systemic reactions. Among all enrolled, 11 died; there was no evidence to suggest any deaths were vaccine-related. CONCLUSIONS: No unexpected patterns of adverse events were detected, providing additional data on the safety of these COVID-19 vaccines in Nigerian adults. We demonstrated that implementing CEM was feasible and may be valuable for safety monitoring of vaccines introduced in LMICs.

BACKGROUND: Hepatitis B virus (HBV) and neonatal tetanus infections remain endemic in Nigeria despite the availability of safe, effective vaccines. We aimed to determine health facilities' capacity for hepatitis B vaccine birth dose (HepB-BD) and maternal tetanus-diphtheria (Td) vaccination and to assess knowledge, attitudes, and practices of HepB-BD and maternal Td vaccine administration among health facility staff in Nigeria. MATERIALS AND METHODS: This was a cross-sectional study assessing public primary and secondary health facilities in Adamawa and Enugu States. A multistage sampling approach was used to select 40 facilities and 79 health-care workers (HCWs) from each state. A structured facility assessment tool and standardized questionnaire evaluated facility characteristics and HCW knowledge, attitudes, and practices related to HepB-BD and maternal Td vaccination. Frequencies and proportions were reported as descriptive statistics. RESULTS: The survey of 80 facilities revealed that 73.8% implemented HepB-BD and maternal Td vaccination policies. HepB-BD was administered within 24 h of birth at 61.3% of facilities and at all times at 57.5%. However, administration seldom occurred in labor and delivery (35%) or maternity wards (16.3%). Nearly half of the facilities (46.3%) had HCWs believing there were contraindications to HepB-BD vaccination. Among 158 HCWs, 26.5% believed tetanus could be transmitted through unprotected sex, prevented by vaccination at birth (46.1%), or by avoiding sharing food and utensils. 65% of HCWs knew HBV infection had the worst outcome for newborns. CONCLUSIONS: The limited implementation of national policies on HepB-BD and maternal Td vaccination, coupled with knowledge gaps among HCWs, pose significant challenges to timely vaccination, necessitating interventions to address these gaps.

BACKGROUND: In 2022, the U.S. Centers for Disease Control and Prevention collaborated with implementing partners, African Field Epidemiology Network and Sydani Group, to support COVID-19 vaccination efforts in Nigeria. To characterize the costs of COVID-19 vaccination, this study evaluated financial costs per dose for activities implemented to support the intensification campaign for COVID-19 vaccination. METHODS: This retrospective evaluation collected secondary data from existing expenditure and programmatic records on resource utilization to roll out COVID-19 vaccination during 2022. The study included incremental financial costs of the activities implemented to support an intensification campaign for COVID-19 vaccination across nine states and six administrative levels in Nigeria from the perspective of the external donor (U.S. Government). Costs for vaccines and injection supplies, transport of vaccines, and any economic costs, including government in-kind contributions, were not included. All costs were converted from Nigerian Naira to 2022 U.S. Dollars (US$). RESULTS: The estimated financial delivery cost of the COVID-19 vaccination intensification campaign was US$0.84 per dose (total expenditure of US$6.29 million to administer 7,461,971 doses). Most of the financial resources were used for fieldwork activities (86%), followed by monitoring and supervision activities (8%), coordination activities (5%), and training-related activities (1%). Labor (58%) and travel (37%) were the resource inputs that accounted for the majority of the cost, while shares of other resource inputs were marginal (1% for each). Most labor costs (79%) were spent on payments for mass vaccination campaign teams, including pay-for-performance incentives. By administrative level, the largest share of costs (46%) was for pay-for-performance incentives at the community, health facility, or campus levels combined, followed by local government area level (24%), community level only (15%), state level (9%), national level (3%), campus level only (1%), and health facility level only (< 1%). CONCLUSIONS: Findings from the evaluation can help to inform resources needed for vaccination activities to respond to future outbreaks and pandemics in resource-limited settings, particularly to reach new target populations not regularly included in routine childhood immunization delivery.

BACKGROUND: Nigeria has the largest number of children infected with hepatitis B virus (HBV) globally and has not yet achieved maternal and neonatal tetanus elimination. In Nigeria, maternal tetanus diphtheria (Td) vaccination is part of antenatal care and hepatitis B birth dose (HepB-BD) vaccination for newborns has been offered since 2004. We implemented interventions targeting healthcare workers (HCWs), community volunteers, and pregnant women attending antenatal care with the goal of improving timely (within 24 hours) HepB-BD vaccination among newborns and Td vaccination coverage among pregnant women. METHODS: We selected 80 public health facilities in Adamawa and Enugu states, with half intervention facilities and half control. Interventions included HCW and community volunteer trainings, engagement of pregnant women, and supportive supervision at facilities. Timely HepB-BD coverage and at least two doses of Td (Td2+) coverage were assessed at baseline before project implementation (January-June 2021) and at endline, one year after implementation (January-June 2022). We held focus group discussions at intervention facilities to discuss intervention strengths, challenges, and improvement opportunities. RESULTS: Compared to baseline, endline median vaccination coverage increased for timely HepB-BD from 2.6% to 61.8% and for Td2+ from 20.4% to 26.9% in intervention facilities (p < 0.05). In comparison, at endline in control facilities median vaccination coverage for timely HepB-BD was 7.9% (p < 0.0001) and Td2+ coverage was 22.2% (p = 0.14). Focus group discussions revealed that HCWs felt empowered to administer vaccination due to increased knowledge on hepatitis B and tetanus, pregnant women had increased knowledge that led to improved health seeking behaviors including Td vaccination, and transportation support was needed to reach those in far communities. CONCLUSION: Targeted interventions significantly increased timely HepB-BD and Td vaccination rates in intervention facilities. Continued support of these successful interventions could help Nigeria reach hepatitis B and maternal and neonatal tetanus elimination goals.

In 2011, a dedicated consortium of experts commenced work on the development of the novel oral poliovirus vaccine type 2 (nOPV2). After careful and rigorous analysis of data to enable early, targeted use of the vaccine, World Health Organization´s (WHO´s) Strategic Advisory Group of Experts on Immunization (SAGE) reviewed data from accelerated clinical development of nOPV2 and endorsed entering assessment under WHO´s Emergency Use Listing (EUL) procedure. In November 2020, nOPV2 received an interim recommendation for use under EUL to enable rapid field availability and potential wider rollout of the vaccine. In December 2020, Nigeria initiated preparation to meet all criteria for initial use of nOPV2 in the country and the documentation process to verify meeting them. The process entailed addressing the status of meeting 25 readiness criteria in nine categories for nOPV2 use in Nigeria for response efforts to ongoing cVDPV2 outbreaks. During January-February 2021, Nigeria submitted the required documentation for all required indicators for nOPV2 initial use. In February 2021, the country obtained approval from the GPEI nOPV2 Readiness Verification Team to introduce nOPV2 and in March 2021, rolled out the novel vaccine in mass vaccination campaigns for outbreak response in Bayelsa, Delta, Niger, Sokoto and Zamfara states, and one area council in the Federal Capital Territory (FCT). The lessons learned from this rollout experience in Nigeria are being applied as the country streamlines and strengthens the nOPV2 rollout process across the remaining states.

INTRODUCTION: in 2016, a switch from trivalent oral poliovirus vaccine (OPV) (containing serotypes 1,2,3) to bivalent OPV (types 1,3) was implemented globally. We assessed the seroprevalence of poliovirus antibody levels in selected Nigerian states, before and after the switch, documented poliovirus type2 outbreak responses conducted and ascertained factors associated with immunity gaps based on seroprevalence rates. METHODS: we conducted a secondary analysis of stored serum samples from the 2018 Nigeria National HIV/AIDS Indicator and Impact Survey. Serum from 1,185 children aged 0-119 months residing in one southern and four northern states were tested for serotype-specific PV neutralizing antibodies; seropositivity was a reciprocal titer ≥8. We conducted regression analysis to determine sociodemographic risk factors associated with low seroprevalence using SAS 9.4. RESULTS: children aged 24-119 months (pre-switch cohort) had seroprevalence against PV1, PV2, and PV3, of 97.3% (95% CI:96.4-98.2), 93.8% (95% CI:92.2-95.5), and 91.3% (95% CI:89.2-93.4), while children aged <24 months (post-switch) had seroprevalence of 86.0% (95% CI:81.2-90.8), 55.6% (95% CI: 47.7-63.4), and 77.2% (95% CI:71.0-83.4) respectively. Regression analysis showed age <24 months was associated with lower seroprevalence against all PV serotypes, (p<0.0001); females had lower seroprevalence against PV1 (p=0.0184) and PV2 (p=0.0354); northern states lower seroprevalence against PV1 (p=0.0039), while well-water source lower seroprevalence against PV3 (p=0.0288). CONCLUSION: this study showed high seroprevalence rates against PV 1, 2, and 3 in pre-switch children (aged 24-119 months). However, post-switch children (<24 months) had low immunity against PV2 despite outbreak responses. Strategies to increase routine immunization coverage and high-quality polio campaigns can increase immunity against polio virus.

Nigeria is estimated to have the largest number of children worldwide, living with chronic hepatitis B virus (HBV) infection, the leading cause of liver cancer. Up to 90% of children infected at birth develop chronic HBV infection. A birth dose of the hepatitis B vaccine (HepB-BD) followed by at least two additional vaccine doses is recommended for prevention. This study assessed barriers and facilitators of HepB-BD administration and uptake, using structured interviews with healthcare providers and pregnant women in Adamawa and Enugu States, Nigeria. The Consolidated Framework for Implementation Sciences Research (CFIR) guided data collection and analysis. We interviewed 87 key informants (40 healthcare providers and 47 pregnant women) and created a codebook for data analysis. Codes were developed by reviewing the literature and reading a subsample of queries line-by-line. The overarching themes identified as barriers among healthcare providers were: the lack of hepatitis B knowledge, limited availability of HepB-BD to vaccination days only, misconceptions about HepB-BD vaccination, challenges in health facility staffing capacity, costs associated with vaccine transportation, and concerns related to vaccine wastage. Facilitators of timely HepB-BD vaccination included: vaccine availability, storage, and hospital births occurring during immunization days. Overarching themes identified as barriers among pregnant women were lack of hepatitis B knowledge, limited understanding of HepB-BD importance, and limited access to vaccines for births occurring outside of a health facility. Facilitators were high vaccine acceptance and willingness for their infants to receive HepB-BD if recommended by providers. Findings indicate the need for enhanced HepB-BD vaccination training for HCWs, educating pregnant women on HBV and the importance of timely HepB-BD, updating policies to enable HepB-BD administration within 24 hours of birth, expanding HepB-BD availability in public and private hospital maternity wards for all facility births, and outreach activities to reach home births.

Nigeria had a confirmed case of COVID-19 on February 28, 2020. On March 17, 2020, the Nigerian Government inaugurated the Presidential Task Force (PTF) on COVID-19 to coordinate the country's multisectoral intergovernmental response. The PTF developed the National COVID-19 Multisectoral Pandemic Response Plan as the blueprint for implementing the response plans. The PTF provided funding, coordination, and governance for the public health response and executed resource mobilization and social welfare support, establishing the framework for containment measures and economic reopening. Despite the challenges of a weak healthcare infrastructure, staff shortages, logistic issues, commodity shortages, currency devaluation, and varying state government cooperation, high-level multisectoral PTF coordination contributed to minimizing the effects of the pandemic through early implementation of mitigation efforts, supported by a strong collaborative partnership with bilateral, multilateral, and private-sector organizations. We describe the lessons learned from the PTF COVID-19 for future multisectoral public health response.

Nigeria began administering COVID-19 vaccines on 5 March 2021 and is working towards the WHO's African regional goal to fully vaccinate 70% of their eligible population by December 2022. Nigeria's COVID-19 vaccination information system includes a surveillance system for COVID-19 adverse events following immunisation (AEFI), but as of April 2021, AEFI data were being collected and managed by multiple groups and lacked routine analysis and use for action. To fill this gap in COVID-19 vaccine safety monitoring, between April 2021 and June 2022, the US Centers for Disease Control and Prevention, in collaboration with other implementing partners led by the Institute of Human Virology Nigeria, supported the Government of Nigeria to triangulate existing COVID-19 AEFI data. This paper describes the process of implementing published draft guidelines for data triangulation for COVID-19 AEFI data in Nigeria. Here, we focus on the process of implementing data triangulation rather than analysing the results and impacts of triangulation. Work began by mapping the flow of COVID-19 AEFI data, engaging stakeholders and building a data management system to intake and store all shared data. These datasets were used to create an online dashboard with key indicators selected based on existing WHO guidelines and national guidance. The dashboard went through an iterative review before dissemination to stakeholders. This case study highlights a successful example of implementing data triangulation for rapid use of AEFI data for decision-making and emphasises the importance of stakeholder engagement and strong data governance structures to make data triangulation successful.

The number of wild poliovirus (WPV) cases in Nigeria decreased from 1,122 in 2006 to six WPV type 1 (WPV1) in 2014 (1). During August 2014-July 2016, no WPV cases were detected; during August-September 2016, four cases were reported in Borno State. An insurgency in northeastern Nigeria had resulted in 468,800 children aged <5 years deprived of health services in Borno by 2016. Military activities in mid-2016 freed isolated families to travel to camps, where the four WPV1 cases were detected. Oral poliovirus vaccine (OPV) campaigns were intensified during August 2016-December 2017; since October 2016, no WPV has been detected (2). Vaccination activities in insurgent-held areas are conducted by security forces; however, 60,000 unvaccinated children remain in unreached settlements. Since 2018, circulating vaccine-derived poliovirus type 2 (cVDPV2) has emerged and spread from Nigeria to Niger and Cameroon; outbreak responses to date have not interrupted transmission. This report describes progress in Nigeria polio eradication activities during January 2018-May 2019 and updates the previous report (2). Interruption of cVDPV2 transmission in Nigeria will need increased efforts to improve campaign quality and include insurgent-held areas. Progress in surveillance and immunization activities will continue to be reviewed, potentially allowing certification of interruption of WPV transmission in Africa in 2020.