Based on Indian as well as global data, the risk of severe disease and death is rare in adolescents and children younger than 12 years. Adults have almost 15 times higher risk of death and severe disease compared with children below 18 years. Even susceptibility to infection is low in younger children.
At least six States in India reopened schools in mid-August, while schools in Tamil Nadu and Rajasthan reopened on September 1. However, contrary to scientific evidence and ICMR recommendations, except Bihar where classes for primary and middle-school students were reopened on priority, all other States did the reverse — first reopened classes for secondary school students.
“States prioritising schools for higher classes and not reopening primary schools reflects many things. One, scientific and epidemiological evidence is not what is used for decision making. Two, policy makers go by the assumption that older children are more likely to follow COVID-appropriate behaviour. Finally, the decision is also influenced by fear and apprehension among parents that younger children may be at higher risk,” says Dr. Chandrakant Lahariya, physician-epidemiologist.
“Based on Indian as well as global data, the risk of severe disease and death is rare in adolescents and children younger than 12 years. Adults have almost 15 times higher risk of death and severe disease compared with children below 18 years,” Dr. N.K. Arora, a senior member of National COVID-19 Task Force had earlier told The Hindu. While children can get asymptomatic infection or have very mild disease, the risk of severe disease or death is rare.
Even susceptibility to infection is low in younger children. According to epidemiologist Dr. Giridhara Babu at Bengaluru’s Public Health Foundation of India, 15 contact-tracing studies indicate that children and adolescents have lower susceptibility to SARS-CoV-2 infection than adults. “If you examine the data carefully, lower susceptibility is mostly confined to children younger than 10-14 years,” he says.
In an email, Dr. Lahariya says: “The available global data on age distribution of COVID-19 indicates that all children are naturally at low risk from COVID-19. The age distribution of moderate to severe illness and mortality follows a ‘J’ shaped curve, where at the base of the ‘J’ are 10-year-old children who are at the lowest risk among all age groups.”
He adds: “Children aged 6-14 years or the age group in the primary and upper primary schools form the base of the ‘J’ and have the lowest risk of COVID-19. Amongst other reasons, this is why primary schools must be the first to resume classes.”
Seroprevalence in children comparable with adults
The fourth serosurvey of ICMR did indicate that seroprevalence in children was comparable to adults. Seroprevalence among children aged 6-17 years was about 60% (57.2% among children 6-9 years and 61.6% among children 10-17 years), while unvaccinated adults had 62% seropositivity. According to Dr. Lahariya independent serosurveys undertaken in a few cities have found seropositivity around 75% for children. Thus, the notion that children have been largely sheltered leading to low seroprevalence and thus have elevated risk of infection and disease once schools reopen is not supported by data.
Especially when daily cases are well under control in most parts of the country, the risk of reopening schools is minimal precisely because seropositivities from prior infection exceed 50% currently across the country and in a number of States this number is in excess of 60-70%, says Dr. Gautam Menon, Professor of Physics and Biology at Ashoka University and co-author of COVID-19 modelling studies. “There should be no major impact of opening schools and colleges in terms of setting up a large second wave, although cases will rise,” he says.
However, even when children may not suffer from serious illness, they are very likely to spread the virus to adults leading to an increase in cases particularly in areas with lower seroprevalence. This becomes particularly concerning when they transmit the virus to adults older than 60 years and those with comorbidities who are more vulnerable to severe disease and even death.
Vaccination and testing
This brings the focus back to targeted vaccination of teachers and non-teaching staff at schools and parents of school-going children. Any plan for reopening schools should include strategies to mitigate the risk to parents, teachers, and all other contacts to enable children’s safety bubbles, says Dr. Babu. This strategy of providing a protective ring around children helps in reducing their risk of getting infected and spreading the infection to adults. Tamil Nadu and Karnataka had started vaccinating teachers on priority some time back. Dr. Menon says that in modelling, there is certainly some mitigation that results due to targeted vaccination of parents and teachers.
The States that have already reopened schools have recorded new cases among children but no large outbreaks have been reported. There has also been a concomitant increase in testing of school children in States where schools have reopened. “These cases in children are the outcome of improved testing and reporting. What we need to remember is that infection is common in children and that is not an immediate concern at this stage of the pandemic,” says Dr. Lahariya.
Will regular testing in schools and colleges help prevent or minimise outbreaks? “There’s never been a test of this in any evidence-based way, so we don’t really know. While some US-based campuses, such as Cornell, do this and have been successful in controlling outbreaks, the levels of prior exposure and seropositivity there are considerably less than in India, so the same intuition might not apply,” says Dr. Menon. Dr. Lahariya doesn’t see any particular benefit accruing from regular testing in schools. “It could be a good idea to conduct testing in schools. However, knowing the fact that children do get infected and do not develop severe disease, it is not very clear what purpose it would serve,” he says.
The priority should be on making sure COVID-appropriate behaviour is strictly adhered to at all times both by teachers and students. Important in this is mask wearing. The Health Ministry has recommended masks for anyone older than five years, and this should be followed in schools as well. According to Dr. Babu, Karnataka COVID-19 Technical Advisory Committee has recommended masks for children older than two years.
Increased ventilation, reduced crowding by limiting the number of students in a class, increased physical distancing, reduced mixing of different cohorts, and more outdoor activity can further reduce the risk of virus spread.
When cases in children get reported, how should schools decide when to shut down? In nearly all countries, reporting of a case or a few cases in the schools does not mean school shutdown. Children are already exposed and that’s why classes may continue, Dr. Lahariya says. “However, if a few clusters of cases are reported or cases are reported from more than one class, then other measures need to be taken. However, I repeat finding one or a few cases does not mandate school or class closure,” he says.