Trial tests which COVID-19 booster combos ‘boost’ immunity

Covid Vaccine

Telethon Kids Institute is recruiting participants for an ongoing national COVID-19 booster study to

work out if immunity can be maximised by mixing different boosters, to ensure Australians get

optimal protection as the virus mutates.

The recruitment drive comes amid new research findings concluding the original COVID-19 boosters

provide limited protection against new strains, leading to the newer XBB.1.5 booster being added to

the study.

Research signals COVID-19 is still a reality, with ongoing boosters the best remedy to prevent

infection – yet the question of which booster combinations work best remains unanswered.

The $8 million trial – referred to as PICOBOO – is funded by the Medical Research Future Fund and

will find out which booster combinations are better matched to the Omicron variants circulating.

Researchers are also testing how long protection lasts and if different variants react in the same way

to boosters across different ages.

Professor Peter Richmond, Head of the Vaccine Trials Group at the Wesfarmers Centre of Vaccines

and Infectious Diseases, based at the Telethon Kids Institute, Head of Paediatrics at The University of

Western Australia and Head of Immunology at Perth Children’s Hospital said the research was

essential to ensure robust and long-term COVID-19 vaccination strategies.

“We know COVID-19 isn’t going away and we need to adapt to learn to live with new variants that

circulate and identify which vaccines give the best immune response to the current circulating

strains,” Professor Richmond said.

It is also clear from the initial results of this study, that the original COVID-19 vaccines used as

boosters, do not provide neutralising antibodies against the strains now circulating in Australia, so it

is important the most vulnerable people are receiving a booster better matched to the Omicron

variants we now have.

“The PICOBOO study urgently needs people aged 12 years of age and above, who have had two or

more vaccines of varying combinations to help us pinpoint the best booster combos so Australians

can be better safeguarded from the virus.”

The study is specifically looking to recruit individuals who are keen to receive a booster vaccination who belong to the following groups:

• teens aged 12 to 17 who had two doses of Pfizer or Moderna as their baseline vaccines

• adults aged 50-69 years of age who have received two doses of Pfizer or Astra Zeneca as their baseline vaccines

• seniors aged 70+ years of age who have had two doses of Astra Zeneca as their baseline vaccine.

To be eligible, participants must not have had a booster in the last three months. More information about how to get involved in the trial is available at