COVID-19 Vaccine Effectiveness Studies against Symptomatic and Severe Outcomes during the Omicron Period in Four Countries in the Eastern Mediterranean Region
Manuela Runge,
Zahra Karimian,
Mehrnaz Kheirandish,
Giulio Borghi,
Natalie Wodniak,
Kamal Fahmy,
Carsten Mantel,
Thomas Cherian,
Zeinab Nabil Ahmed Said,
Farid Najafi,
Fatima Thneibat,
Zia Ul-Haq,
Sheraz Fazid,
Iman Ibrahim Salama,
Fatemeh Khosravi Shadmani,
Ahmad Alrawashdeh,
Shadrokh Sirous,
Saverio Bellizzi,
Amira Ahmed,
Michael Lukwiya,
Arash Rashidian,
on behalf of the Consortium of Authors
Affiliations
Manuela Runge
MMGH Consulting, 8049 Zurich, Switzerland
Zahra Karimian
Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt
Mehrnaz Kheirandish
Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt
Giulio Borghi
MMGH Consulting, 8049 Zurich, Switzerland
Natalie Wodniak
MMGH Consulting, 8049 Zurich, Switzerland
Kamal Fahmy
Division of Communicable Diseases, WHO Regional Office for the Eastern Mediterranean, Cairo 11516, Egypt
Carsten Mantel
MMGH Consulting, 8049 Zurich, Switzerland
Thomas Cherian
MMGH Consulting, 8049 Zurich, Switzerland
Zeinab Nabil Ahmed Said
Department of Medical Microbiology and Immunology, Faculty of Medicine (for Girls), Al-Azhar University, Cairo 11651, Egypt
Farid Najafi
Research Center for Environmental Determinants of Health (RCEDH), Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6713954658, Iran
Fatima Thneibat
Jordan Ministry of Health, Amman 11118, Jordan
Zia Ul-Haq
Institute of Public Health and Social Sciences, Khyber Medical University, Peshawar 25100, Pakistan
Sheraz Fazid
Institute of Public Health and Social Sciences, Khyber Medical University, Peshawar 25100, Pakistan
Iman Ibrahim Salama
Department of Community Medicine Research, National Research Centre, Cairo 12622, Egypt
Fatemeh Khosravi Shadmani
Research Center for Environmental Determinants of Health (RCEDH), Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6713954658, Iran
Ahmad Alrawashdeh
Department of Allied Medical Sciences, Jordan University of Science and Technology, Amman 3030, Jordan
Shadrokh Sirous
WHO Country Office for Iran, Tehran 8453193445, Iran
Saverio Bellizzi
WHO Country Office for Jordan, Amman 11181, Jordan
Amira Ahmed
WHO Country Office for Egypt, Cairo 11516, Egypt
Michael Lukwiya
WHO Country Office for Pakistan, Islamabad P.O. Box 1013 44000, Pakistan
Arash Rashidian
Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt
Vaccine effectiveness (VE) studies provide real-world evidence to monitor vaccine performance and inform policy. The WHO Regional Office for the Eastern Mediterranean supported a regional study to assess the VE of COVID-19 vaccines against different clinical outcomes in four countries between June 2021 and August 2023. Health worker cohort studies were conducted in 2707 health workers in Egypt and Pakistan, of whom 171 experienced symptomatic laboratory-confirmed SARS-CoV-2 infection. Test-negative design case–control studies were conducted in Iran and Jordan in 4017 severe acute respiratory infection (SARI) patients (2347 controls and 1670 cases) during the Omicron variant dominant period. VE estimates were calculated for each study and pooled by study design for several vaccine types (BBIBP-CorV, AZD1222, BNT162b2, and mRNA-1273, among others). Among health workers, VE against symptomatic infection of a complete primary series could only be computed compared to partial vaccination, suggesting a benefit of providing an additional dose of mRNA vaccines (VE: 88.9%, 95%CI: 15.3–98.6%), while results were inconclusive for other vaccine products. Among SARI patients, VE against hospitalization of a complete primary series with any vaccine compared to non-vaccinated was 20.9% (95%CI: 4.5–34.5%). Effectiveness estimates for individual vaccines, booster doses, and secondary outcomes (intensive care unit admission and death) were inconclusive. Future VE studies will need to address challenges in both design and analysis when conducted late during a pandemic and will be able to utilize the strengthened capacities in countries.
