AIIMS-WHO joint study suggests "positive" seroprevalence; similar among children & adults

On Friday, AIIMS Delhi Director Dr Randeep Guleria said that the outcome of the joint survey by the World Health Organisation- AIIMS, which found out COVID-19 seroprevalence was 55.7 per cent and 63.5 per cent in the age group below 18 and above respectively, is "positive". He did mention there was a need for larger nationwide sample size for more comprehensive results.

"The outcome of the survey is positive. It is very reassuring that if it is happening here, it will also happen in other parts of the country," Dr Guleria told ANI.

The study has underlined that there was no statistically significant difference in prevalence between adult and children. More importantly, the seroprevalence among children and adults in the same regions were similar.

What is seroprevalence?

The seropositivity rate is the rate of having a positive serum reaction especially in a test for the presence of antibodies. It is not confined to the COVID-19 virus, but all types of infection. In scientific terms, the SARS-CoV-2 seropositivity rate among children was high compared to the adult population in the survey.

In India's context, the result was on the basis of data collected from 4,500 participants that were taken from four states for mid-term analysis, and more results are likely to come in the next two to three months.

Speaking about this, Dr Guleria said, "This study also looked at sero surveillance among children who did not know they were infected. In less than 18 years of age group, it was found that more than 50 per cent of children and in some areas, more than 80 per cent of children from both urban and rural areas had antibodies. This means they were already infected and developed antibodies."

Commenting on the study findings that overall 62.3 per cent, which is more than half of the rural population surveyed, showed evidence of past infection, the AIIMS Delhi Director ascertained that it is unlikely that a large number of children will get infected with COVID-19. 

Possible COVID-19 third wave unlikely to affect children much?

However, AIIMS Director highlighted the following two issues have been pointed out in this regard,

• firstly, a large number of children get a mild infection and recuperated as well, and
• secondly, significant children in India have already got the infection therefore the chances of them getting the infection is low

"Based on this data or data available globally, it is unlikely that children will get a severe infection or a large number of children will get infected," Dr Guleria stated.

According to Dr Guleria, if antibodies can be found it means "there is some degree of protection and some people have cell-mediated immunity". He informed that once a person is infected with COVID then within subsequent four to six months, the antibody will tend to come down while the person's cell-mediated immunity would continue to process for months and years ahead.