The infectious nature of the severe acute respiratory coronavirus 2 (SARS-CoV-2) has caused three powerful waves of the pandemic to spread through the populations of different countries.
As the Coronavirus 2019 (COVID-19) pandemic has disproportionately affected the elderly, there is a belief that children can carry the virus from school to their grandparents, who have a higher mortality rate from acquiring this virus. For this reasoning and for prevention purposes, schools were advised to close.
Now, a group of researchers from India have explored this concept due to the lack of solid evidence and have undertaken a community and population-based serosurveillance study for the coronavirus infection under the World Health Organisation (WHO) Unity umbrella. In this study, participants older than two years old were compared to older adults in terms of seropositivity.
A pre-print version of the paper is available on the medRxiv* server, while the article undergoes peer review.
This research was conducted in five areas within India: New Delhi; Bhubaneswar, Odisha; Gorakhpur, Uttar Pradesh; Puducherry; Agartala, Tripura, and consisted of both the urban and rural areas within these sites.
The geographical location of the study sites in India
The study encompassed approximately 1,000 participants in each of the urban and rural sites, with an attempt to achieve 40 participants within 10 houses in each cluster – this overall enabled the enrolment of 10,000 participants in all five sites.
The data which was reported consisted of an age range of 2 to 17-years-old individuals, collected within different periods for the various sites from between 15th March to 1st June. The participants’ serum antibody reactivity to SARS-CoV-2 was the primary variable which was measured using enzyme-linked immunosorbent assay (ELISA) in order to assess the total antibody level in the serum.
Susceptibility within age groups
The study's findings consisted of children having a slightly lower seropositivity rate than adults, with the seropositivity rate for children being 55.7% compared to the adults who had 63.5%. This supports previous literature and the conclusion that children are less affected by the virus than adults, however, this lack of significance also could suggest the susceptibility in the two age groups to be similar.
The researchers explore the limitations of measuring susceptibility to infection, discussing that with schools remaining closed, the only exposure to the infection that the children have is through adults who leave the house for a job and grocery purposes or other essential journeys.
Additionally, the scientists mention the lack of clarity on whether children are able to produce the same level of antibodies as adults. If their production level is lower, then it might be challenging to identify and detect this through existing laboratory tests.
This theory would affect the result of this hypothesis as it would affect whether children are less, equal, or more susceptible to the virus than the adults, and the lack of sensitivity of current laboratory tests may cause the antibody levels of the children to not be detected effectively.
Other limitations and strengths which have also been explored by the researchers of this pre-print paper include, the sampling technique and representation of the population.
Due to the five sites comprised in this study and 25 different clusters, various geographical locations within India have been covered and this assists the study and its associated results with being representative of the population.
However, cluster sampling was used as a sampling method, and this included choosing a site in New Delhi that consisted of a high population of low socio-economic individuals within the sample, which may cause the results of this site to be less representative of the city as a whole.
This study aimed to explore the concept of susceptibility in different age groups (2-17-years-old), with the theory that children are less susceptible to the SARS-CoV-2 virus compared to their older counterparts.
The research undertaken by the scientists, which overlooked results from five different sites in India, has found that the seropositivity rate was still high in children and can be comparable to the rates in adults.
The researchers conclude that children have a high SARS-CoV-2 seropositivity rate that is comparable to adults. So it is unlikely that any future third wave would disproportionately affect children aged two or older by prevailing SARS-CoV-2 variants.
medrxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.