Limited immune responses after three months of BNT162b2 vaccine in SARS-CoV-2 uninfected elders living in long-term care facilities

Abstract Background SARS-CoV-2 vaccination is the most effective strategy to protect elders living in long-term care facilities (LTCF) against severe COVID-19, but primary vaccine responses are less effective in older adults. Here, we characterized the humoral responses following 3 months after mRNA/BNT162b2 vaccine in institutionalized elders.Methods Plasma levels of specific SARS-CoV-2 total IgG, IgM and IgA antibodies were measured before and 3 months after vaccination in elders living in LTCF. Neutralization capacity was assessed in a pseudovirus neutralization assay against WH1 (original) and B.1.617.2/Delta variants. A group of younger adults was used as reference group.Results Three months after vaccination, uninfected-elders presented reduced specific SARS-CoV-2 IgG levels and significantly lower neutralization capacity against the WH1 and Delta virus compared to vaccinated uninfected younger individuals. In contrast, COVID-19 recovered elders showed significantly higher specific SARS-CoV-2 IgG levels after vaccination than younger counterparts, while showing similar neutralization activity against WH1 virus and increased neutralization capacity against Delta variant. Despite previously infected elders elicit potent cross-reactive immune responses similarly to younger individuals, higher quantities of specific SARS-CoV-2 IgG antibodies are required to reach the same neutralization levels.Conclusions While hybrid immunity seems to be active in previously infected elders after three months from mRNA/BNT162b2 vaccination, humoral immune responses are diminished in COVID-19 uninfected vaccinated residents living in LTCF. These results suggests that a vaccine booster dose should be prioritized for this particularly vulnerable population.Word summary While previously infected and vaccinated elders living in LTCF had comparable neutralizing antibody levels to younger individuals, vaccinated uninfected-residents showed limited neutralization capacity against both original and delta variants. Hybrid immunity seems to be active in elders and can be relevant to design vaccine boosting campaigns..

Medienart:

Preprint

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

bioRxiv.org - (2024) vom: 23. Apr. Zur Gesamtaufnahme - year:2024

Sprache:

Englisch

Beteiligte Personen:

Trigueros, Macedonia [VerfasserIn]
Pradenas, Edwards [VerfasserIn]
Palacín, Dolors [VerfasserIn]
Ávila-Nieto, Carlos [VerfasserIn]
Trinité, Benjamin [VerfasserIn]
Bonet-Simó, Josep Maria [VerfasserIn]
Isnard, Mar [VerfasserIn]
Moreno, Nemesio [VerfasserIn]
Marfil, Silvia [VerfasserIn]
Rovirosa, Carla [VerfasserIn]
Puig, Teresa [VerfasserIn]
Grau, Eulàlia [VerfasserIn]
Chamorro, Anna [VerfasserIn]
Martinez, Ana [VerfasserIn]
Toledo, Ruth [VerfasserIn]
Font, Marta [VerfasserIn]
Ara, Jordi [VerfasserIn]
Carrillo, Jorge [VerfasserIn]
Mateu, Lourdes [VerfasserIn]
Blanco, Julià [VerfasserIn]
Clotet, Bonaventura [VerfasserIn]
Prat, Nuria [VerfasserIn]
Massanella, Marta [VerfasserIn]

Links:

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Themen:

570
Biology

doi:

10.1101/2021.11.18.21266502

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI033054835