Feasibility of Cohort Event Monitoring and Assessment of Reactogenicity and Adverse Events Among a Cohort of AstraZeneca and Moderna COVID-19 Vaccine Recipients in Nigeria, 2021.

Details

• Alternative Title:
  Vaccine, 2025, v. 52: Feasibility of Cohort Event Monitoring and Assessment of Reactogenicity and Adverse Events Among a Cohort of AstraZeneca and Moderna COVID-19 Vaccine Recipients in Nigeria, 2021.
• Journal Article:
  Vaccine
• Personal Author:
  Bolu, Omotayo ; Alo, Oluwafemi D. ; Iwara, Emem ; Longley, Ashley T. ; Hadley, Ikwe ; Ogar, Comfort K. ; Ezekwe, Chukwuka ; Elemuwa, Uchenna ; Adedokun, Oluwasanmi ; Ramadhani, Habib O. ; Ohakanu, Stephen ; Ortiz, Nancy ; Antonza, Gladys ; Abubakar, Asmau ; Asekun, Adeyelu ; Fraden, Bitrus ; Chen, Robert ; Nordenberg, Dale ; Adebajo, Sylvia ; Adeyeye, Moji Christianah ; Stafford, Kristen A.
• Corporate Authors:
  Nigeria COVID-19 Vaccine Cohort Event Monitoring Implementation Group
• Description:
  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.
  
  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.
  
  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.
  
  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.
• Content Notes:
  Author manuscript
• Subjects:
  • Humans
  • Female
  • COVID-19
  • COVID-19 Vaccines
  • Male
  • Adult
  • Middle Aged
  • Feasibility Studies
  • ChAdOx1 nCoV-19
  • Young Adult
  More +
• Keywords:
  • Adverse events following immunization
  • Nigeria
  • Reactogenicity
  • Cohort event monitoring
  • Serious adverse events
  • AstraZeneca COVID-19 vaccine
  • Moderna COVID-19 vaccine
  • Vaccine safety
  • Post-introduction surveillance
  • Feasibility
• Source:
  Vaccine, 2025, v. 52
• DOI:
  https://doi.org/10.1016/j.vaccine.2025.126907
• ISSN:
  0264-410X ; 1873-2518
• Pubmed ID:
  40073670
• Pubmed Central ID:
  PMC11975468
• Document Type:
  Text
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/ ; GH002108/CC/CDC HHSUnited States/
• Genre:
  Journal Article
• Place as Subject:
  Nigeria
• Pages in Document:
  126907 (23 pdf pages)
• Volume:
  52
• Download URL:
  https://stacks.cdc.gov/view/cdc/261605/cdc_261605_DS1.pdf
• File Type:
  [PDF - 523.50 KB]
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:e15b502e80d092200c8fa8da25256258b35691356fb09ce1eb2fae65df749d819b25ab909e5ce5ae557cceb3cc2879560d47b9b7c6c5425084a5dd4887f2d6dd