Effectiveness of the vaccine (Covaxin®) on different age groups of people: A pilot study

Abstract

BackgroundCovaxin® is a COVID-19 vaccine created and produced by Bharat Biotech in India. The vaccine is based on the strain of SARS-CoV-2 that was first identified in India and has undergone Phase III clinical trials. Covaxin® has been authorized for emergency use in India and has been distributed as part of India's vaccination campaign. The vaccine has been shown to be effective in preventing COVID-19 infection and hospitalization, but additional studies are needed to determine its efficacy as well as safety in the long term. MethodsThe antibody titer against Covaxin® was detected through indirect ELISA immunoassay. Optimization was performed on 500 samples to get an idea and work further on a larger number of samples. ResultsThe vaccine had the best immune response in individuals between the ages of 21 and 30 and the least response in those between 61 and 70. This was attributed to the phenomenon of immunosenescence, which explains the weakening of the immune system with age. Additionally, the study found that the equine anti-CoV-19 serum had a higher binding affinity with Covaxin®, highlighting the effectiveness of horse Ig against COVID-19 antigens. ConclusionsThe study concluded that Covaxin® was effective in generating an immune response in individuals after 2 doses of vaccination; however, the generated immune response decreased with the time of vaccine administration and the age of the vaccinated. The study also showed that the ELISA technique used in this research is an efficient and sensitive method to evaluate vaccine efficiency and can be applied to a larger number of samples for further comparative analysis.