Comparative analysis of antibody production by mRNA 1273, AZD 1222 and BBIBP-CorV on elderly people suffering from different co-morbidity in Bangladesh

Background: As the pandemic spread so quickly all over the world, the scientist did not get the right time to cover all age group populations for a vaccine trial. The elderly population is usually vulnerable for COVID-19 which was proven by different research work and focus was to save this group of people was the prime concern for every country of the world. Though vaccines that got emergency use authorization have proven their efficacy which one is better for elderly people suffering from different co-morbid conditions is still not established. In this study, we want to evaluate the antibody production by mRNA 1273, AZD 1222, and BBIBP-CorV in elderly people with different comorbidity. Method: We include 40 people in each group who have at least one comorbid condition and the total sample size was 120. The sample was taken from them before vaccination and 14 days after the second dose. Adverse event following immunization was recorded if any. Antibody measurement was done by ELISA method by using DiaSino SARS-CoV-2 S1 RBD IgG Quant. Result: Among 120 participants with an equal number of participants in each of the vaccine groups all of them were aged between 60-72 years, of whom 65% were males and 35 % were females. Anti S1 RBD IgG was detected among all the participants from each vaccine group after 14 days of taking their 2nd dose. A non-parametric multiple comparison test (Kruskal-Wallis test) of Anti S1 RBD IgG levels among three vaccine groups revealed significant differences (P-value <0.05) between groups. The IgG level was almost twice in the mRNA-1273 group compared to AZD1222 and BBIBP-CorV group. Conclusion: From this small sample size, we predicate that mRNA 1273 produces much higher anti-S1 RBD IgG than the other two vaccines. Every vaccine is safe and effective whose is approved by WHO. Calculative use of the vaccine may produce an outcome for the future as we are still way behind in the proper amount of vaccine production.