Independent report

Vivaldi 3: reduced antibody and cellular immune responses following dual COVID-19 vaccination within infection-naive residents of long-term care facilities

Published 10 December 2021

Methodology

The Vivaldi 3 study, conducted by the University of Birmingham in collaboration with University College London, is an integral part of the Vivaldi project which was set up in June 2020 to investigate SARS-CoV-2 transmission, infection outcomes and immunity in residents and staff in care homes in England.

For this paper, researchers studied blood samples from 202 staff and 286 residents in care homes to investigate their antibody and cellular immune responses following COVID-19 vaccination. Blood sampling was carried out between December 2020 and June 2021.

Results

Antibody responses following dual vaccination in both staff (younger than 65 years) and residents (older than 65 years) with previous SARS-CoV-2 infection were strong and similar across all age groups.

Antibody responses were just over 8 times (8.1) lower in elderly residents who had not had prior natural SARS-CoV-2 infection compared to those with previous infection. In contrast these values were just under 2 and a half times (2.4) lower in care home staff, suggesting that younger age may help to overcome this effect.
This means that care home residents without prior infection had just over 2 and a half times (2.6) lower antibody response than the younger staff.

Cellular immunity is also thought to be important in controlling disease severity. Spike-specific T cell responses were seen to be 52% lower in residents without prior natural infection compared to those who had previously had a natural infection.

Conclusion

Care home residents and staff who have previously contracted and survived COVID-19 develop much stronger and higher antibody and cellular immune responses following 2 doses of vaccination than those without prior natural infection.

The findings emphasise the need for all care home residents to increase their immunity protection through receiving their 2 primary vaccine doses and third booster vaccines.

See the Vivaldi 3 report.