The antibody levels start decreasing six weeks after complete inoculation with Pfizer and AstraZeneca COVID-19 vaccines, and can decrease by over 50% over 10 weeks, suggests a study published in The Lancet.

Investigators from University College London (UCL), UK noted that if the antibody levels continue to decline at this rate, the protective effects of the vaccines may also start to dwindle, especially against the new variants. The UCL Virus Watch study noted that antibody levels were considerably higher after two doses of the Pfizer vaccine compared to the AstraZeneca vaccine. Additionally, the levels of antibodies were higher in vaccinated individuals compared to those who had a previous SARS-CoV-2 infection… (ET Healthworld – PTI, July 28, 2021)