The recent approval of a COVID vaccine for infants and preschoolers is a boost needed in Canada’s ongoing battle with the pandemic, says Brock University immunologist Adam MacNeil.

Health Canada announced Thursday that the Moderna vaccine has been approved for children between six months and five years old.

“This is a monumental step toward maximizing the vaccine layer of protection across our communities as we continue to wrestle with the evolution of one of the most transmissible pathogens in human history and learn more about its long-term impacts on health outcomes,” says MacNeil, Associate Professor of Immunology.

The children’s vaccine works in exactly the same way as the adult version, he says, with very mild — and no serious — side effects reported to date.

Brock University immunologist Adam MacNeil.

“As a parent of an under-five-year-old myself, and someone who has dedicated significant time to studying immunity at its most fundamental level, I will absolutely be vaccinating my child,” MacNeil says.

At one-quarter the size of the standard adult dose, Moderna’s latest vaccine takes children’s smaller bodies into account, “with the lower dose being optimized to ensure a safe and effective immune response,” he says.

MacNeil explains that the children’s dose contains 25 micrograms of messenger RNA (mRNA) as compared to the 100 micrograms found in the adult version. This will be translated into a protein and shown to the immune system to create a protective immune response in the form of antibodies and T cells, he says.

“The bottom line is that independent scientific review of the evidence on vaccine efficacy has demonstrated that the benefits of receiving the vaccine outweigh the risks and that the immune response is similar to that seen in those 18 to 25 years old,” he says.

MacNeil notes that polio, diphtheria, pertussis, measles, smallpox and other pathogens have been completely or nearly wiped out thanks to routine childhood vaccination schedules.

Meanwhile, COVID-19 continues to pose a threat to children. MacNeil says that in Ontario, 23 children from newborn to four years have recently been hospitalized for COVID, while a similar number is attributed to the entire five-to-39-year-old age range.

Like many other viruses, COVID-19 infection may also have long-term effects that aren’t fully understood yet, he says.

He encourages parents who have concerns or questions about their children’s unique situations to talk to their child’s health-care provider.

MacNeil says that while most or all people will likely be exposed to the COVID-19 virus at some point, research has shown multiple infections lead to increasingly negative health outcomes on the body’s tissues and organs.

“These aren’t dice you want to roll,” he says. “You want to catch this as few times as you can. Vaccines will help with that and protecting our youngest and most vulnerable is a big step toward minimizing the transmission chain with the tools we have available to us.”