COVID-19 infection after vaccination

Although vaccination is the most effective and specific approach for prevention of infectious diseases, but in a small percentage of vaccinated person's breakthrough infections can occur. This study aimed to determine the effectiveness of different common coronavirus vaccines in this area.

109 COVID-19 vaccinated patients were enrolled, with different types of vaccines (Sinopharm, AstraZeneca, Sputnic, Bharath, CovIran Barkat and Pasto-CoV) and time of administration in 2021 in Babol, Iran. Patients after 14 days of administration of the final dose of corona vaccines with positive COVID-19 RT-PCR test entered to study. Patients' data such as RT-PCR, type of vaccine, age, sex and outcome were collected using electronic medical records.

47 patients were not fully vaccinated, 62 had two vaccine doses and 51 were fully vaccinated and considered to a breakthrough infection. Although, most of the patients with SARS-CoV-2 infection were either mild (n=18 [16.56%]), or moderate (n=86 [78.9%]), 5 (4.6%) patients had severe or critical illness, of whom 3 admitted in intensive care unit, 3 intubated, and 4 died. The average age of the participants with COVID-19 infections was 61.23 ± 19.91 years.

Based on our results, the COVID-19 breakthrough occurring with two doses of current vaccines were mild and moderate.