ABSTRACT
Background: Countries around the world are now racing to vaccinate people against SARS-CoV-2, the virus that causes COVID-19. The Government of India also rolled out its vaccination drive from 16th January ‘2021. Aims: To estimate the antibody response of the COVID-19 vaccine in the form of SARS-COV-2 IgG antibodies in vaccinated healthcare workers. Methods: Prospective follow-up was study conducted on healthcare workers (HCWs) of a Medical college in Dehradun, Uttarakhand. Healthcare workers who have been vaccinated for COVID-19 were tested for SARS-CoV-2-IgG antibodies at regular intervals i.e at 4 weeks after the 1st dose and then again at 4 weeks after the 2nd dose. The third sample was taken 6 months after the 2nd dose. Results: A total of 302 HCWs were enrolled in the study who gave their samples for IgG antibody estimation after the Covishield vaccine. After 4 weeks of completion of both doses, 96% HCWs formed SARS-COV-2 IgG antibodies, whereas 4% didn’t. Then after 6 months of follow-up, 14% HCWs have become negative for antibodies and better immunity is seen in people who also got infected with COVID-19 during this time. Conclusion: This study concludes that the immunity gained after vaccination is waning off in around 6 months and there is a need for a booster dose, especially for people at high risk. The infection control practices still play a crucial role in the prevention of this deadly disease.