About 60.1% population, including 55% children in the age group of 6-9 years, has had a silent prior exposure to SARS-CoV-2 as per the sero-positivity rate found during the fourth round of the sero-prevalence study led by the ICMR-National Institute of Nutrition (ICMR-NIN) in the districts of Jangoan, Nalgonda and Kamareddy recently.
In an official communique on Friday, the ICMR-NIN informed that the survey has been taken up in association with the State Health department. It covered all age groups, like in the previous three phases, in addition to children in the age group of 6-7 years, for the first time in this fourth phase.
About 61% adolescents had COVID antibodies and among healthcare workers, the sero-positivity was as high as 82.4%, and this is being attributed to early vaccination to frontline workers. The ICMR strategy has been to do repeat cross-sectional sero-studies in the same geographic locations so that the infection transmission trends could be documented and studied.
The first round of the sero-survey, conducted in May 2020, and the second and third rounds, conducted in August and December 2020, in the same districts showed a sero-prevalence of 0.33%, 12.5% and 24.1% respectively. The sero-prevalence at the national level went up from 24% in December 2020 to 67% in June 2021. However, in Telangana, it went up from 24.1% to 60.1% during the same time.
Interestingly, the study also found that among those who were not vaccinated at all, the sero-positivity was low at 51.3%, while among those who received one dose of vaccination, it was 78.5 and it was 94% among those who got both the shots. “Near 100% sero-positvity among those vaccinated clearly indicates that vaccines are effective. This should remove any vaccine hesitancy and encourage people to get vaccinated as early as possible,” said head of Public Health Division, ICMR-NIN and nodal officer for the Telangana study Dr. A. Laxmaiah,
“Over 40% of population is still susceptible to the virus, although over 60% people have anti-bodies. This is not the time to lower our guard. All non-pharmacological COVID measures like wearing masks, hand sanitisation, and physical distancing should be continued,” cautioned ICMR-NIN director Dr. Hemalatha.
