SYDNEY – An Australian and Canadian study has found that childhood COVID-19 vaccination not only leads to high relative reductions in child disease and mortality, but also benefits adults, particularly the unvaccinated.

The findings, published in MedRxiv and released by the Griffith University on Monday, came at the same time when vaccinations for children aged five to 11 commence in Australia. The researchers used a mathematical epidemiological model to forecast the effect of childhood vaccination on the number of COVID-19 cases, hospitalizations, deaths, complications and vaccine adverse effects in both children and in adults.

They found that for children aged five to 11, cases of vaccine-associated myocarditis and anaphylaxis are predicted to be very rare. And vaccinating children would generate an “altruistic” reduction in the number of adult cases, hospitalizations and mortality, particularly among the unvaccinated.

“Our model showed that childhood vaccination carries minimal risk, yet can result in large relative reductions in the disease,” said Professor Michael Good from the Institute for Glycomics of the Griffith University. “Under less intense epidemic conditions, when the effective reproduction rate is slightly greater than 1, the type of modest reductions seen in adult populations due to childhood vaccination can lead to large reductions in the disease.”

Three million vaccines are being distributed on Monday ahead of the start of the school year to enable the 2.3 million children now eligible to be vaccinated. The research showed that the biggest benefit of childhood vaccination will, perhaps, be seen in adult populations because of the implication for immunization programs.

The implication for immunization programs of this effect on adult populations is that childhood vaccination has the greatest potential for population-wide impact when coupled with other public health measures, such as social distancing, masking, improved hand hygiene and adult vaccination, to maximise the reduction in cases.

The researchers thought that while the modeling for this study was generated using publicly available data for the Delta strain of coronavirus, it is predicted that the relative impacts of Omicron on children and adults as a result of vaccination of children will be similar.