Effectiveness and safety of inactivated SARS-CoV2 vaccine (BBIBP-CorV) among healthcare workers: A seven-month follow-up study at fifteen hospitals

OBJECTIVE Health care workers_ the first line army in the current pandemic_ are the most vulnerable group for COVID-19 infection. Vaccination of health care workers is strongly recommended to salvage our army. However, more research is needed to determine the safest and most effective vaccine. In our study, we assessed the safety and effectiveness of the first approved vaccine in Egypt_ the Sinopharm vaccine. DESIGN, SETTING: An ambispective cohort study was conducted in fifteen triage and isolation hospitals, from the 1st of March till the end of September 2021. Participants are either fully vaccinated or unvaccinated. OUTCOMES AND MEASURES: Efficacy outcome to assess vaccine effectiveness, severity outcome to assess incidence rate of hospitalized cases (severe to critically ill) or the COVID-19 related mortality, in addition to the safety of the vaccine. INTERPRETATION: From the selected hospitals, we included 1228 of 1364 interviewed healthcare workers. Vaccine effectiveness was 67% to protect against symptomatic PCR confirmed cases and 46% for total COVID-19 infection after adjusting hazard ratio. Incidence rate ratios of vaccinated to unvaccinated group were 0.39 (95%CI, 0.24–0.65) for PCR confirmed symptomatic case, 0.63 (95%CI, 0.46–0.86) for total COVID-19 infection, 0.45 (95% CI, 0.15–1.31) for hospitalization, 0.71 (95% CI, 0.07– 6.39) for mechanical ventilation and only one COVID-19 death among unvaccinated group. Most adverse events are mild and well-tolerated. Pregnant and lactating vaccinated mothers did not report any sentinel adverse events. CONCLUSION Sinopharm was effective in protecting health care workers from the highly transmissible COVID-19 infection when the predominant Delta variant was ambient.