why we need covid shots for children to end the pandemic

as the slow march to covid vaccination in older age clusters continues, word this week that pfizer’s covid vaccine appears extraordinarily good at protecting 12- to 15-year-olds was “great,” though not entirely surprising news, said dr. fatima kakkar.pfizer’s vaccine is already authorized for ages 16 and older, and younger teens aren’t that much different.the bigger question is the pre-puberty age group — below 11 — and younger infants. “there we have to be really careful with dosing,” said kakkar, an infectious diseases pediatrician at chu sainte-justine in montreal. “the response might be different.”covid shots for children are coming, perhaps in time for the next school year in the fall, at least for younger high-schoolers, and provided we have the vaccines. scientists say this life-halting pandemic won’t end until children are inoculated. but, one year into the pandemic, it is still not clear what role children play in spreading the virus, or which children should be vaccinated first.the virus is adapting to its human hosts, trying to spread as much as possible. the third wave is here, and being driven by hyper-contagious variants deadlier than earlier circulating ones. younger adults are ending up in hospital, sometimes connected to lung bypass pumps. ontario scientists warned this week that, for adults, the risk of being admitted to an icu is two times higher, the risk of death 1.5 times greater if infected with the variant first seen in southeast england in november, and that’s now driven ontario and b.c. into new shutdowns. kakkar so there is so far no evidence of increased severity in children.a few months from now, barring a manufacturing crisis or another covid curve ball, most of the country’s adult population should have immunity, either because they’ve been infected or they’ve been vaccinated. if children are the biggest part of the population left susceptible, “we may end up seeing them being more important in transmission going forward,” said dr. manish sadarangani, director of the vaccine evaluation centre at b.c. children’s hospital.“we’ve seen what’s happened in children over the last year,” he said. unlike seasonal flus and colds, children don’t appear to be major drivers of covid. but we may be underestimating the role they’re playing.

their symptoms tend to be mild, so they may be less likely than adults to get tested. and some studies suggest infection rates in children are similar to adults. “when we adjust for under-testing of kids under 10, we find that their risk is the same as that in adults 70 and older,” university of toronto epidemiologist david fisman tweeted this week.nationally, the highest proportion of covid infections (22 per cent as of mar. 26) are in those 19 and under.once most adults have received their two doses, “i think at that point we need to take stock and see how many cases are we still seeing — what is the role of children,” said sadarangani. the pediatric infectious diseases specialist is leading a project testing blood samples (a few drops from a finger prick) from just over 2,500 children and youth, 25 and younger, across b.c. for antibodies to the sars-cov-2 virus — a marker they’ve been infected in the past. this will help  get a true handle on how many children have been exposed through the plague.once vaccines are approved for children, “we need to think about this logically in the same way we’ve approached the adult program,” sadarangani said, meaning, who should get priority?“think about the current vaccines we use in children,” he said. “there are very few that we vaccinate across the entire childhood spectrum.” most are targeted at specific age groups, some particularly at infants, where the most severe disease or transmission occurs, others adolescents.pfizer inc and biontech said this week, citing as yet unpublished data, that their covid-19 vaccine was 100 per cent effective and produced “robust” antibody responses in 12 to 15-year-olds, based on early results from a phase 3 trial involving 2,260 teens (the adult trials involved 30,000). the company has also begun testing its vaccine on children as young as six months. moderna, johnson & johnson, novavax and oxford-astrazeneca have already begun, or plan to, test their vaccines in young children.age reigns supreme as the greatest risk factor for severe outcomes from covid — hospitalizations and deaths. so far, six deaths have been reported in the youngest age group (0 to 19).the same age group accounts for about 1.6 per cent of hospitalizations in canada, according to data compiled by the canadian paediatric surveillance program. almost half of those are incidental: a child arrives in emergency with a bone fracture, and a routine screening test happens to pick up covid.of those hospitalizations related to covid, more than half are mild. the only severe cases tend to be in that 12- to 17-year-age range, when they look more physiologically like adults, with underlying health problems such as obesity, high blood pressure or chronic lung disease.vaccines being tested on young children are using smaller doses, typically half the adult dose, because younger children tend to have more robust immune responses.“kids haven’t really been severely infected by covid, so before we give them anything we have to make sure that there’s no immediate side effects, or in the months following the vaccine, to make sure there’s nothing that comes out of an overactive immune response to the vaccine,” kakkar said.children can have a much stronger immune response to covid itself, triggering a hyper inflammatory syndrome not seen in adults. it starts six to eight weeks after a covid infection with persistent fever, fatigue, fussy eating, abdominal pain and other symptoms. after every peak of covid, “we see a pretty constant flow of cases,” said kakkar, an associate professor of paediatrics at the university of montreal.doctors know how to treat the syndrome; they’re able to recognize it, and they’re trying to understand it. the immune system somehow goes into overdrive, and there is a concern children might react to a vaccine in a similar way. “before we roll out this vaccine we want to make sure there’s absolutely no signal for that,” kakkar said.but covid will never be quelled until children are vaccinated, she and others say. kids are part of the herd, and “we know that they will eventually be a component for maintaining or establishing herd immunity,” pediatric allergist dr. mariam hanna said at a recent ontario medical association briefing for reporters.school closures, the constant interruptions, have had a devastating impact. quebec has closed schools in hot spots quebec city and gatineau. saskatchewan’s teachers are calling for online learning after easter. even before the latest restrictions, across the country, “our pediatric wards are overflowing with teenagers who’ve decompensated as a result — i’m talking suicide attempts, overdoses, severe eating disorders, psychoses, depression,” kakkar said.more than year into the pandemic, why covid has behaved so differently in children compared to adults remains a puzzle, she said. they may have fewer receptors lining their airways the sars-cov-2 virus binds to. but that doesn’t fully explain it.“i’ve learned to respect this virus, and be humble,” kakkar said “i’m just a little worried about what might be next, what the next twist with this virus will be.”• email: skirkey@postmedia.com | twitter: sharon_kirkey