Reopening schools is unlikely to cause a third Covid-19 wave or lead to a large increase in cases in adults, even with the more infectious Delta variant, experts say and scientific research has shown. With a majority of India's children having lost a year-and-a-half of learning, the benefits of opening schools with precautions far outweigh the risks.
An analysis of various studies shows that there was limited Covid-19 transmission in schools if precautions such as wearing masks, ensuring ventilation in classrooms and avoiding overcrowding were followed. Despite the more transmissible Delta variant having increased the number of Covid-19 cases in those below 18 years in the UK and the US, severe cases and deaths are still at similar levels as in 2020 and the rate of severe cases and deaths is lower in children than older people, data and research show.
While a soon-to-be-released modeling study shows that school reopening is unlikely to cause a third Covid-19 wave in India, experts point out that high seropositivity among children shows that the lockdowns and school closures did not protect children from getting infected. Further, the risk of infection from children to adults is low, studies have shown. What schools must do, though, is ensure that all precautions such as distancing and mask-wearing are adhered to, while all adults get vaccinated.
"The question, is it safe to reopen schools, is incorrect," said Swapneil Parikh, internal medicine specialist and author of The Coronavirus: What You Need to Know about the Global Pandemic. "The question is about weighing costs. Keeping schools closed has possibly had the highest costs to society, without clear tangible benefits. We don't really know that this has had a huge impact at slowing community spread of Covid-19. The benefits of in-person schooling are greater than the risks of in-school Covid-19."
This story weighing the benefits and risk of schools reopening is the third in our 'Education Disrupted' series, which began with the impact of pandemic-related school closures on children and learning, and continued with what schools must do to reopen.
Modelling shows schools unlikely to lead to third wave
In a yet-to-be published modelling study, researchers Gautam Menon, Brian Wahl and Sandeep Krishna have attempted to estimate how reopening schools might impact Covid-19 infections among children and adults in India. They factored in a community with schools, workplaces and people shuffling between these, different seropositivity levels in the community from natural infection as well as vaccines for Covid-19, and non-pharmaceutical interventions such as masking, Menon, professor of physics and biology at Ashoka University in Sonepat, told IndiaSpend.
"An increase in cases in children is expected as schools are opened, relative to keeping them closed," the researchers wrote in The Hindu on September 2. "But there is likely to be only a small increase in Covid-19 infections, including in adults, and this is unlikely to start a third wave," Menon told IndiaSpend. "Specifically, in regions with the levels of seroprevalence expected across much of north India, we expect this increase in cases to be marginal," they wrote in The Hindu.
Overall, 68% of Indians had antibodies for Covid-19, either because of vaccination or natural infection, according to the fourth nationwide serosurvey by the Indian Council of Medical Research, the results of which were released in July. At around 70-75% seropositivity in a district, it would be safe to reopen schools, and it would be reasonable to expect this level of seropositivity across most districts in India, said Menon. But district-level sero-surveys have not been conducted across all of India's districts, which should be undertaken to make more informed decisions on opening schools, Menon suggested.
School closures did not protect children from infection
Even with schools closed, "we have not done a good job of keeping Covid-19 infection away from children, who have anyway picked it up from the community", Menon said. The fourth national serosurvey showed that despite school closures, and without vaccines, over half (57.2%) of children, aged six-nine years, had Covid-19 antibodies, while 61.6% of those between 10-17 years had antibodies, we reported in July 2021.
"While a measure of last resort, school closures can contribute to a reduction in SARS-CoV-2 transmission, but are by themselves insufficient to prevent community transmission of COVID-19 in the absence of other nonpharmaceutical interventions and the expansion of vaccination coverage," said the European Centre for Disease Control (ECDC) in its update on school reopenings and Covid-19 in July 2021.
Further, they found that the effectiveness of school closures in the European Union "appears to have declined in the second wave as compared to the first wave of the COVID-19 pandemic, possibly in part due to better hygiene measures in school settings".
In India too, school reopenings are recommended with a slew of precautions including masking, physical distancing, effective ventilation and adult vaccination, IndiaSpend had reported in September 2021.
Children unlikely to transmit infection more than adults
The early basis for school closures was that transmission in communities increased because of schools and if schools were closed, it would help control the spread, explained Brian Wahl, an assistant scientist in Global Disease Epidemiology and Control at Johns Hopkins University in the US. "But now we know that children do not drive transmission. They can of course bring the infection back to families but the best way to reduce severe disease and hospitalisation in older individuals--teachers and family--is to immunise them and reduce their risk," he added.
Several studies show that schools and children were not the primary mode of transmission of the SARS-CoV-2 virus, which causes Covid-19. In the US's North Carolina, in August 2020, over 90,000 staff and students attended school in person. Of 805 infections detected over nine weeks, only 32 were traced back to in-school transmission. Studies in Wisconsin, in New York, in Utah and in Norway also show few Covid-19 cases in schoolchildren or staff because of in-person learning, and low transmission within schools.
Further, children would be less likely to transmit infections, and those who do would also transmit Covid-19 for a shorter duration because children are more likely to have mild and asymptomatic infections, found a review of 35 studies published in March 2021.
At the same time, the risk of transmission is greater from similar-aged people, both for children and adults, and as such school interaction could lead to greater infection in children, found a study from Andhra Pradesh and Tamil Nadu, which included Covid-19 cases until August 1, 2020. Similarly, a study from the US, published in June 2021, found that living in a household with a child going to school, especially high school children, would more likely result in a positive Covid-19 test. But when "mitigation measures are in place, transmission within schools is limited and infection rates mirror that of the surrounding community", the authors of the study wrote.
In England too, a study in December 2020 showed that Covid-19 cases in schools were uncommon, and were linked more closely with the level of cases in the community rather than school-based transmission. "The strong association with regional COVID-19 incidence emphasises the importance of controlling community transmission to protect educational settings," the study said.
"The risk to a community from a mass gathering of children is no greater than from a mass gathering of adults," said Parikh. In India, "it's not like we are saying that anything that has risk--such as bars, restaurants and weddings--should be shut, we are just saying that schools should be shut. Schooling is far more essential than any of these activities."
What is important is that the decision to send children to schools be personal, said Parikh. For instance, a family might choose not to send to school a child with a comorbidity, or one who lives with a parent or elderly grandparent who has cancer or any such disease that makes their immune system especially weak.
Further, if some parents, especially those who can continue to care for and educate the child at home, keep them from school, there would be lower risk of going to school (with fewer students) for those who do not have the same privileges, Parikh said.
Schools should not open without precautions
Where there were few precautions in place, there have been Covid-19 outbreaks in schools. In May 2021, an unvaccinated teacher in California, who taught unmasked, infected nearly half the class she taught, with the infection spreading to siblings and parents, the US CDC found. This shows the "potential for rapid spread, especially in unvaccinated populations such as schoolchildren too young for vaccination", the study said. Yet, large-scale "transmission might have been prevented by high levels of community vaccination; at the time of this outbreak, approximately 72% of eligible persons in the city where the school is located were fully vaccinated", the study added.
Similarly, there was a large outbreak in a school in Israel 10 days after the school reopened in May 2020, which was linked to large, crowded classes as well as an exception to wearing masks because of a heatwave.
To successfully reopen schools and convince parents to send children to school, the communication around school reopening should change, suggested Parikh. We need to say that "there is a real cost to denying kids education and that the cost exceeds the risks of Covid-19. Also, we are doing scientific things to ensure the safety of your children and reduce that risk further."
"We take extra precautions with children for understandable reasons so if any steps can further reduce the risk, then I am a proponent of those," said Wahl. One important intervention is masks, with high filtration efficiency, that are especially made for children, and ventilation in schools, said Parikh, adding that devices such as carbon dioxide sensors or air filters should be used where possible.
Parikh also suggested testing school sewage for the SARS-CoV-2 virus and in case the virus is found, then additional steps such as testing children or staff, or instituting more precautions, could be taken. Further, as soon as adequate doses are available, India should consider vaccinating adolescents between the ages of 16 and 18 years, he said.
Only at seropositivity of 80-85% or higher, derived both from prior infection or vaccination, can non-pharmaceutical interventions, such as physical distancing, be done away with, as they do not add any extra protection against Covid-19 spread, Menon said.
Not infections, but symptoms need to be tracked
The risk of asymptomatic Covid-19 infection was equal in children, teenagers and working-age adults, while the risk was greater for the elderly or those with comorbidities, found a large-scale SARS-CoV-2 surveillance programme in Madurai between October 19 and November 5, 2020. This was despite schools being shut for most of the first wave of Covid-19 in India.
But experts agree and research shows that Covid-19 infections and school outbreaks are likely to occur. These should not make parents anxious or lead to school shutdowns, experts said.
Parents should instead monitor symptoms very closely for any signs of severe disease, said Menon. "Most children with Covid-19 infection can be easily managed at home," Wahl said. One rare, but dangerous outcome of Covid-19 is Multisystem Inflammatory Syndrome in Children, and parents should be cautious of any symptoms, such as fever, inflammation and rash after recovery from Covid-19, we had reported in May 2021.
Overall, children are at low risk of severe disease or death from Covid-19. For instance, the proportion of deaths from reported Covid-19 cases ranged from 0.05% at ages five to 17 years to 16.6% at 85 years or more, found a study in Andhra Pradesh and Tamil Nadu, that looked at data until August 1, 2020. If seropositivity surveys are considered, adolescents aged 15-19 years have an infection fatality ratio [deaths as a proportion of all infections, not just reported cases] of around 0.001%, that is one of every 100,000 said Wahl, based on the Madurai study.
There is currently no evidence yet that the Delta variant causes more severe disease in children, said Menon and Wahl. In the US, as the Delta variant spread, more children were hospitalised than before, with unvaccinated adolescents more at risk than those vaccinated, a study by the US CDC found. But the higher hospitalisation and ICU admissions in the US are a 'denominator problem', Wahl said, because the Delta variant is much more transmissible and thus affecting a larger absolute number of people.
"No one wants kids to be sick, whatever the infection is, even a common cold," said Parikh. Even though the vast majority of children will have mild Covid-19, in a population where a third of the people are below the age of 18 years, even a low infection rate could lead to a large number of hospitalisations, said Parikh.
Knowing how the health system failed during the second wave is an opportunity for India to ramp up health facilities and pediatric health facilities, not because it will be needed for Covid-19 but because we know we have a "gaping hole" in our health infrastructure, said Parikh, citing the example of scarce hospital beds during dengue and malaria outbreaks, especially in rural India.
In addition, "opening schools in the middle of a Delta wave is very different from opening schools several months after a Delta wave. I don't think we can fairly make comparisons across different settings that are dealing with different stages of their own local epidemics," Wahl said.