Efficacy and Safety of COVID-19 Vaccines in Older People

Roy L. Soiza; Chiara Scicluna; Emma C. Thomson


Age Ageing. 2021;50(2):279-283. 

In This Article

Adjuvanted Protein Vaccines

A more traditional approach to vaccine development is the use of purified protein extracts from the offending organism, usually given in combination with an adjuvant to boost the immune response. Both the Novavax and GSK/Sanofi vaccines consist of purified pre-fusion stabilised SARS-CoV-2 spike protein, harvested from genetically modified viruses, akin to those described above. Novavax has staged its first phase III study of 15,000 people exclusively in the UK, with another planned in the USA due to start before the end of the year. Although the trials will recruit a minimum of 25% of people aged 65 and over, those aged 85 or over and those with complex comorbidity are excluded. Phase II data for older people have not been published to date—in younger people, much like the other candidate vaccines, a strong antibody response was observed with self-limiting mild to moderate local and systemic side effects observed in over a third of recipients.[9] The GSK/Sanofi candidate vaccine entered phase I/II trials in September, recruiting 400 healthy participants from the USA and is yet to report any results despite plans to start Phase III testing in December 2020. Therefore, published safety and efficacy data for adjuvanted protein vaccines in older people are currently minimal, though initial results from ongoing studies are expected imminently.