COVID-19 disease modelling experts at The University of Western Australia have found vaccinating children aged five to 11 years would reduce the number of cases, hospitalisations and deaths from outbreaks of the COVID-19 Delta variant in Australia. 

Vaccinating this younger age group is now under consideration in the US and is a step closer to being approved in Australia, with Pfizer asked to submit trial data to the Therapeutic Goods Administration TGA) and The Australia Technical Advisory Group on Immunisation (ATAGI). Both would need to approve the application for an extended rollout to proceed in Australia.

Lead researcher Professor George Milne and his team from UWA’s Department of Computer Science and Software Engineering carried out computer simulation modelling of the highly transmissible COVID-19 Delta variant. 

The researchers applied a high-resolution model to evaluate the benefits of adding children as well as adolescents to current COVID-19 vaccination programs, while also determining the reduction in cases, hospitalisations and deaths through social distancing when Delta first appears in a community. 

The modelling showed that if there was a Delta outbreak in a community of a million people and 80 per cent of people aged 12 and over were fully vaccinated, we could expect to see around 1,162 people hospitalised, in the absence of any social distancing measures.

“If we included COVID-19 vaccinations for children aged five and above, the number of people hospitalised is estimated to drop to 1,073, and by activating moderate social distancing with schools remaining open, hospitalisations are predicted to reduce to 705,” Professor Milne said.

“If 90 per cent of those five years old and over were fully vaccinated, we found people hospitalised would drop to 533 in the absence of any form of lockdown. If moderate social distancing measures were enforced, our modelling suggests no hospitalisations or deaths would occur.

“Our research suggests that significant outbreaks of the Delta variant may continue to occur once borders reopen unless vaccination reaches very high levels in adults and teens. 

“At an 80 per cent vaccination rate in these age groups, moderate lockdown measures will still be necessary to contain Delta variant transmission. Our modelling also demonstrates the benefit of vaccinating children aged 5 to 11 years, though COVID-19 vaccines have yet to be approved for this age group.” 

The research is funded by the Western Australian and Queensland departments of health. It is published as a preprint on medRxiv and has not been peer reviewed.