Sinopharm's Covid booster dose has been shown to generate weaker immune responses against the new highly transmissible Omicron variant, which is known to evade vaccine efficacy. The hyper-mutated Omicron variant of concern has spread to approximately 90 countries, raising serious concerns about vaccine efficacy and the risk of re-infection. Researchers from Shanghai Jiao Tong University and a Shanghai-based lab specialising in respiratory infectious diseases conducted a study in which they compared the activity of Sinopharm's booster vaccine against an older coronavirus strain from Wuhan. The yet-to-be peer-reviewed study found that the neutralising antibody activity of a Sinopharm BBIBP-CorV booster against Omicron was reduced by 20.1-fold when compared to its activity against a Wuhan strain. The study included 292 healthcare workers who were given a third homologous boosting vaccination eight to nine months after the priming two-dose inactivated vaccination. The researchers wanted to see if the newly discovered Omicron variant could avoid serum antibody neutralisation caused by the booster vaccination. According to the findings, a third booster dose of BBIBP-CorV results in a significant rebound in neutralising immune response against SARS-CoV-2. On day 28, after the third booster dose, the neutralisation titer was 6.1 times higher than on day 28 after the second dose. Study reveals, Omicron replicates in airways 70 times faster than delta Four hospitals designated for Omicron in Delhi ICMR says - No scientific evidence that Covid tablets will be useful now