COVID-19 Vaccination for Frail Older Adults in Singapore - Rapid Evidence Summary and Delphi Consensus Statements

This study aimed to synthesize available evidence on the effectiveness and safety of COVID-19 vaccines for frail older adults through a rapid review, supplemented with geriatricians' consensus statements.

References were identified through MEDLINE and Web of Science on 1st February 2021 using relevant terms related to COVID-19, vaccine, and older adults. Searches were also conducted on reference lists of review articles and Google Scholar. The content was updated on 8th April via hand searching. We included studies on Phase III randomized controlled trials, and data from real world administration of vaccines. A two-round Delphi study was conducted with 15 geriatricians to elicit their thoughts and recommendations regarding COVID-19 vaccination for frail older adults.

Five Phase III randomized controlled efficacy trials reported vaccine efficacy ranging from 66.7% to 95% among participants aged 16 to 95. The vaccine efficacy for participants aged 65 and above is 94.7% and 86.4% for Pfizer-BioNTech and Moderna respectively. Sputnik V reported a vaccine efficacy of 91.8% for participants 60 and above. Serious adverse events were reported by 0.27% to 1% of participants who received at least one dose of the four vaccines. For the Delphi study, 16 out of 24 statements achieved consensus. The Delphi panel opined that frail or very old adults, except those with limited life expectancy, should be vaccinated due to their vulnerability. They also agree that vaccination decisions should be made by patients when possible, with the involvement of next-of-kin should the frail older adult be unable to do so. Lastly, the panel thought that frail older adults should be included in future clinical trials.

In early clinical trials, there is paucity of evidence on efficacy and safety of current COVID-19 vaccines among frail older adults. Geriatricians' consensus indicate that frail older adults should be vaccinated except where life expectancy is limited. Future trials assessing efficacy and safety should include frail older adults.