New Delhi: Amid fears that a possible third wave could affect children and teens more, a mid-term analysis of a serological survey conducted on children and adults in Delhi and three states has found seroprevalence among children of 2-17 years of age to be 55.7 per cent, thereby assuring the country that this group isn’t disproportionately vulnerable to contracting Covid, at least “the prevailing variant”, should there be a third wave.
The study was approved by the Institutional Ethics Committee of AIIMS, New Delhi, and all other participating institutions, including AIIMS Bhubaneswar, AIIMS Gorakhpur, Translational Health Science and Technology Institute, Faridabad, and the Agartala Government Medical College.
A serological survey analyses the number of people who have developed antibodies to the virus, offering a rough estimate on how much of the population has been exposed to Covid-19.
The AIIMS survey found the seroprevalence in children comparable to the adult population, with 63.5 per cent of respondents in the latter group found to have developed Covid antibodies.
“SARS-CoV-2 sero-positivity rate among children was high and were comparable to the adult population. Hence, it is unlikely that any future third wave by prevailing Covid-19 variant would disproportionately affect children two years or older (sic),” the report read.
The study said data collected is diverse and largely representative. “We, for the first time, provide seroprevalence estimate for children aged 2-17 years. Data from both urban slum area, rural area and some tribal population at one site, further increases the generalizability. By including a large number of clusters (25) within each of the study site makes our findings more representative.”
This result was based on interim data, part of a larger nation-wide multi-centric population-based sero-epidemiological study, which will be conducted on 10,000 people across five states in India.
The data collection was carried out between 15 March and 10 June 2021, and there were 4,509 participants, of which 700 were 18 years and below, and the rest adults.
The results are from Delhi, Gorakhpur, Agartala and Bhubaneswar, covering both urban and rural areas.
The study also found that seroprevalence was lower in rural areas when compared to urban areas. The difference between seroprevalence among children and adults was also higher in the rural areas — 73.9 per cent among urban children and 74.8 per cent among urban adults, in comparison to 52.9 per cent seroprevalence among children and 60 per cent among adults in rural areas.
The study results found higher seropositivity among female children, though the report said this could be due to a sampling issue. “This finding was in contrast to the meta-analysis where it was shown that the prevalence is higher in men. This may be a chance finding due to small number of data available at the time of midterm analysis,” the report said.
The study also found that children between 10 and 17 years of age had a seropositivity of 60.30 per cent, but 50.9 per cent of these positive cases were asymptomatic. For age groups of 2-4 and 5-9 years, the seropositivity stood at 42.4 per cent and 43.8 per cent, respectively. Higher seropositivity in 10-17 age group, the study said, could be because children in this age group enjoy higher mobility.
The study also reported significantly higher seropositivity among the age group of 10-17 than a previous survey. “The second nationwide sero-prevalence study done in August-September 2020 had reported 9.0% seropositive among 3,021 children aged 10-17 years while in our study it is 60.30%.”