Safety Profile of Sinopharm COVID-19 Vaccine and Breakthrough Infections in Pakistan

Background: To determine the safety profile of Sinopharm COVID-19 vaccine and identify breakthrough infections. Method: The study design was analytical cross sectional. An online questionnaire was filled by 1033 respondents between 16th and 22nd April 2021. Adults who had received both doses of Sinopharm COVID-19 vaccine more than a week ago or only a single dose with serious side effect were included in the study. The frequency and severity of vaccination related side effects were assessed and breakthrough infection identified. Results: The mean age of participants was 36.7 ± 12.91(18 – 92) years. Ninety one percent of participants (n=946) were health care professionals. One fifth (n=225/1033, 21.8%) had suffered from COVID-19 infection prior to vaccination, confirmed using the nasal RT-PCR test. None of the participants reported serious (grade III) or life threatening (grade IV) adverse reactions after either of the two doses. The most common side effects after the first dose were pain at injection site (20.3%), fatigue (20.3%), headache (13.9%), myalgia (12.5%) and fever (9.3%) whereas after the second dose were fatigue (16.8%), pain at injection site (15.8%), myalgia (14%) and fever (6.7%). The side effects were more common in participants who had previous history of COVID-19 infection. Of 225 previously infected participants, 97(43.1%) (p value=0.020) and 90 (40%) (p value=0.001) participants had side effects after 1st and 2nd dose respectively. 16 participants (1.55%) developed PCR positive COVID-19 infection two weeks after the second dose while 3(0.29%) participants had a re-infection. There was one case of probable severe COVID-19 infection, 2 weeks after the second dose and recovered completely with treatment. Conclusion: Our study shows that Sinopharm COVID-19 vaccine is generally safe with no serious side effects. The side effects were however, more common in inviduals who already had COVID-19 infection. The COVID-19 breakthrough infection and reinfection could occur after the vaccination.