Receiving a recent COVID-19 booster prevents death in older people, NCIRS study shows

Results from an NCIRS study show that COVID-19 boosters can protect older people against COVID-related death.

According to the study – published in the Medical Journal of Australia – older people in Australia who received a COVID-19 vaccine booster dose in the past 6 months were half as likely to die from SARS-CoV-2 infection compared with those who had a COVID-19 booster more than a year prior.

NCIRS researchers used Australian Bureau of Statistics data to track the outcomes of 4.12 million people aged 65 years and over who were diagnosed with COVID-19 – 1.89 million (45.8%) of whom were aged 75 years and over – between August 2023 and February 2024, to assess the impact of COVID-19 vaccination.  

This vaccine effectiveness study supports the 2025 recommendations that people in Australia who are aged 75 years and over should receive a COVID-19 vaccine booster dose every 6 months to get the best protection against severe outcomes. Adults aged 65–74 years are recommended a COVID-19 vaccine every 12 months and are also eligible for a COVID-19 vaccine every 6 months based on a risk–benefit assessment.  

‘These results are a great reminder of the benefits of vaccination,’ said Professor Bette Liu, lead study author and Associate Director of Population Health at NCIRS. ‘Ongoing monitoring of COVID-19 vaccine effectiveness remains important as we continue to live with the virus, see new strains emerge globally and experience high levels of the virus circulating in the community.’  

These findings build on previous COVID-19 vaccine effectiveness studies from Australia and overseas, which show that receiving a recent booster dose substantially reduces the risk of infection, serious disease and death from COVID-19.  

NCIRS Director and co-author of the study, Professor Kristine Macartney said, ‘The results of this study reinforce that our most vulnerable people in the community can be protected through regularly having a COVID-19 vaccine. We continue to encourage eligible people, especially those aged 75 years and over, to take up a COVID-19 booster if you haven’t done so in the last 6 months.’  

COVID-19 vaccines are free for all people in Australia, including those without a Medicare card. Receiving a COVID-19 vaccine alongside a flu vaccine or other routinely recommended vaccines is safe and encouraged.  

Monitoring the effectiveness of vaccines is important to ensure Australia’s vaccination programs are based on the best available evidence. NCIRS researchers will continue to assess vaccine effectiveness – with more up-to-date data to be published in due course.  

‘Undertaking these types of studies helps us to understand if the vaccine recommendations in place are effective and protecting  those most at risk of severe health outcomes – in this case, our older population,’ concluded Professor Liu.  

The study was funded by the Health Economics Research Division within the Australian Department of Health, Disability and Ageing.  

Access the study