Immune responses following sequential mRNA booster doses targeting the SARS-CoV-2 omicron variants in immunocompromised individuals – A 3.5-year follow-up
Sequential administration of variant-adapted COVID-19 boosters broadened neutralizing activity against Omicron subvariants, although it did not further elevate antibody levels beyond prior doses. T-cell responses remained stable and unenhanced by additional boosting, indicating potential for durable cellular protection despite low or waning antibody levels.
Authors
- Saimi Vara
- Merit Melin (ORCID: https://orcid.org/0000-0001-9375-4327)
- Anu Haveri (ORCID: https://orcid.org/0000-0003-4620-7536)
- Oona Liedes (ORCID: https://orcid.org/0009-0007-1570-4325)
- Ilkka Helanterä (ORCID: https://orcid.org/0000-0002-2954-2538)
- Nina Ekström (ORCID: https://orcid.org/0000-0003-2220-9027)
- Arto A. Palmu (ORCID: https://orcid.org/0000-0001-8071-8896)
- Tuija M. Leino
- Hanna Nohynek
- Maria Heikkilä
- Anna Solastie
Institutions
- University of Helsinki (FI)
- Helsinki University Hospital (FI)
- Finnish Institute for Health and Welfare (FI)
Publication Details
- Journal
- Vaccine
- Published
- 2026-02-24
- DOI
- https://doi.org/10.1016/j.vaccine.2026.128347
- Primary Topic
- SARS-CoV-2 and COVID-19 Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00