It’s been less than three weeks since the Centers for Disease Control and Prevention (CDC) gave the green light for kids aged five and up to get their COVID-19 vaccinations, and already more than 2.6 million children have received their first shot. That leaves just their pre-K siblings as the only cohort in the US still not eligible for the vaccine – but maybe not for long.
Speaking to Business Insider, Dr Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases and Chief Medical Advisor to the President, said he expected the vaccine rollout to reach babies as young as six months old by next Spring – though he was careful not to make any promises.
“Hopefully within a reasonably short period of time, likely the beginning of next year in 2022, in the first quarter of 2022, it will be available to them,” Fauci said, noting that he “can't guarantee it,” without solid evidence from clinical trials.
Although all three vaccines currently available in the US have passed clinical trials in adults, children’s bodies – especially their brains and immune systems – differ in several important ways from their grown-up compatriots’. That’s especially true in toddlers and infants, who are often still reliant on their mothers’ immune systems to boost their own – in fact, there’s even evidence that fetuses and breastfeeding babies get some protection from their mother’s vaccination.
That’s why it’s crucial that any potential vaccines are thoroughly tested on this younger cohort before they become widely available – just like they were for older children and adults before them. Pfizer has the advantage in that regard: their mRNA vaccine is already being trialed on young children across the country, with “quite positive” results, per local researchers. Moderna’s offering may come a little later – they announced a nationwide clinical trial for kids aged six months to five years just last week. Finally, Johnson and Johnson has had plans to run clinical trials on this age group since February – but regulatory delays have meant that the company is still testing its vaccine in 12-17-year-olds for now.
While the effects of COVID-19 infection are generally less severe in younger children, there’s still a risk of deadly outcomes. For example, by one estimate, around one in every 1,000 children who get the illness – even just a mild case – will go on to develop something called multi-system inflammatory syndrome in children (MIS-C), a poorly understood and potentially fatal syndrome.
And just as younger children seem to have their own way of reacting to the disease itself, some immunologists think they may react to the vaccine differently as well. Trials in older children, between the ages of 12 and 15, found that a standard vaccine schedule produced significantly higher antibody levels than in adults. That may sound like good news – and to a certain extent it is – but this strong immune response may make younger children more likely to develop reactions like fevers after vaccination.
Nevertheless, experts are hopeful that the trials will prove successful. Should that be the case, spokespeople from Pfizer say they expect to start vaccinating infants by the end of April 2022.
“There's every reason to think that [vaccines in younger children] will be safe, and it will be efficacious,” Dr Philip Landrigan, a pediatrician and immunologist at Boston College, told CNN. “But the agencies need to be cautious, justifiably so, and so they're not going to give the approval until they have the data.”