A Retrospective Study on the Gam-COVID-Vac (Sputnik V) COVID-19 Vaccine Short-Term Efficacy and Side Effects in Iranian Healthcare Providers

Background: The Gam-COVID-Vac (Sputnik V) COVID-19 vaccine is one of the approved vaccines which has been used in Iran. Objectives: In the present retrospective study, we evaluated the short-term efficacy and side effects of the Sputnik V vaccine against COVID-19 in Iranian healthcare providers. Methods: Healthcare workers referred to Firoozgar Hospital affiliated with the Iran University of Medical Sciences, Tehran, Iran, between March 2021 and December 2021 were assessed. Humoral immunity was evaluated against S-RBD IgG of SARS-CoV2 after Sputnik V vaccination at three phases, including days 60 (phase I), 120 (phase II), and 210 (phase III) by an anti-S RBD IgG ELISA kit. Vaccine recipients were divided into two groups based on the history of SARS-CoV2 infection. The vaccine side effects were obtained from each participant after the first and second doses. Results: A total of 65 vaccine recipients (41.5% male (27/65)) with a mean age of 35 ± 8.5 years were enrolled, of whom 41.5% had a history of COVID-19 infection. The SARS-CoV-2 IgG levels were significantly higher in vaccine recipients compared to those without a history of COVID-19 infection a month (4 vs. 6.6), three months (4.5 vs. 7.2), and six months (3.8 vs. 5.9) after vaccination (P = 0.001). Our study had 18 patients (27.7%) with vaccination breakthroughs. Conclusions: Sputnik V seems to induce high antibody levels after the second dose; however, protective antibodies declined six months after the second dose. A booster dose is highly recommended for at-risk individuals.