4th National Sero Survey of India: Vaccine Generated Antibodies Enhancement


  •   Zameer Shervani

  •   Deepali Bhardwaj

  •   Roma Nikhat

  •   Aiman Ibbrahim

  •   Intazam Khan

  •   Umair Yaqub Qazi

  •   Ankira Agarwal

  •   Adil Ahmed Khan

  •   Sadia Hasan

  •   Abdullah Sherwani


The results of the fourth COVID-19 national serosurvey (June-July 2021) of India have been analysed. Much needed data of vaccine generated antibodies have been reported world first as recorded in Indian population on the ground in real. More than two-thirds of (67.6%) Indian population developed antibodies against the infection. This includes natural immunity build up due to infection and vaccine generated antibodies. Eleven states: Madhya Pradesh, Rajasthan, Bihar, Gujrat, Chhattisgarh, Uttarakhand, Uttar Pradesh, Andhra Pradesh, Karnataka, Tamil Nadu, and Odisha had sero positivity of >67.6%which was the national average. Ten other states registered < 67.6% seroprevalence were: Punjab, Telangana, Jammu and Kashmir, Himachal Pradesh, Jharkhand, West Bengal, Haryana, Maharashtra, Assam, and Kerala. Single dose vaccination of 24% population added 19% seroprevalence in the population whereas 13% full vaccination increased 28% individuals registered antibodies. The highest (90%) seroprevalence was registered among the individuals who have taken both vaccine doses followed by HCWs (85%). Seroprevalence in 85-90% population might be the threshold for herd immunity which delayed or possibly stopped the third COVID-19 wave in India.

Keywords: COVID-19 seroprevalence, fourth serosurvey, herd immunity, SARS-CoV-2 spread, serosurvey of India


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