Vaccine subtype and dose interval determine immunogenicity of primary series COVID-19 vaccines in older people

Helen Parry, Rachel Bruton, Reni Ayodele, Penny Sylla, Graham McIlroy, Nicola Logan, Sam Scott, Sam Nicol, Kriti Verma, Christine Stephens, Brian Willett, Jianmin Zuo, Paul Moss*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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Age is the strongest determinant of COVID-19 mortality, and over 2 billion people have received primary series vaccination with BNT162b2 (mRNA) or ChAdOx1 (adenoviral vector). However, the profile of sustained vaccine immunogenicity in older people is unknown. Here, we determine spike-specific humoral and cellular immunity to 8 months following BNT162b2 or ChAdOx1 in 245 people aged 80-98 years. Vaccines are strongly immunogenic, with antibodies retained in every donor, while titers fall to 23%-26% from peak. Peak immunity develops rapidly with standard interval BNT162b2, although antibody titers are enhanced 3.7-fold with extended interval. Neutralization of ancestral variants is superior following BNT162b2, while neutralization of Omicron is broadly negative. Conversely, cellular responses are stronger following ChAdOx1 and are retained to 33%-60% of peak with all vaccines. BNT162b2 and ChAdOx1 elicit strong, but differential, sustained immunogenicity in older people. These data provide a baseline to assess optimal booster regimen in this vulnerable age group.

Original languageEnglish
Article number100739
JournalCell Reports Medicine
Issue number9
Early online date25 Aug 2022
Publication statusPublished - 20 Sept 2022

Bibliographical note

Copyright © 2022 The Author(s)


  • Aged
  • BNT162 Vaccine
  • COVID-19 Vaccines
  • COVID-19/prevention & control
  • Humans
  • Immunogenicity, Vaccine
  • RNA, Messenger


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