#COVID19 #vaccination induces cross-neutralisation of #sarbecoviruses related to #SARS-CoV-2

 

Abstract

The combined threats of future sarbecovirus zoonosis and continually emerging SARS-CoV-2 VOCs highlight the need to assess the breadth of existing SARS-CoV-2 vaccine-mediated protection. Here, we investigate a cohort of older individuals who received four COVID-19 vaccine doses, for potential cross-neutralisation against lentiviral particles bearing spikes from either Omicron VOCs or other sarbecoviruses. Despite recent fourth bivalent mRNA vaccine doses (encoding SARS-CoV-2 Wu-1 and Omicron spikes), neutralisation of Omicron lineage VOCs was reduced compared to Wu-1, consistent with an imprinted immune response. Similarly, particles bearing either SARS-CoV-1 or a SARS-CoV-1-related bat sarbecovirus spike were neutralised less efficiently than Wu-1. Unexpectedly, however, we observed that particles with spikes from two animal SARS-CoV-2-related viruses, BANAL-20-52 from bats and a pangolin CoV, were significantly more sensitive to serum neutralising antibodies than SARS-CoV-2 Wu-1 itself. These surprising findings suggest that vaccine-mediated adaptive immunity may provide efficient cross-neutralisation and potential protection against certain animal sarbecoviruses.

Source: npj Vaccines, https://www.nature.com/npjvaccines/

Link: https://www.nature.com/articles/s41541-026-01469-x

____

Overcoming immune #imprinting with the #COVID19 #LP81 #mRNA #boosters

 

{Summary}

In summer 2025, the SARS-CoV-2 JN.1 sublineage became dominant with more resistant variants, such as XFG, LP.8.1, and NB.1.8.1. COVID-19 mRNA boosters were therefore updated for the 2025–2026 season to target the LP.8.1 spike.1 Previous boosters, particularly the WA1/2020+BA.5 bivalent booster, were characterised by substantial boosting of the ancestral strain, a phenomenon known as immune imprinting.2,3 We therefore evaluated whether the phylogenetically more distant LP.8.1 mRNA booster would preferentially boost currently circulating strains. Recent data from European and Asian populations have reported the immunogenicity of the LP.8.1 mRNA booster.4,5 Herein, we report the immunogenicity of the LP.8.1 mRNA booster in a US population with a different exposure history and high population immunity. We show that the LP.8.1 mRNA booster induced neutralising antibody (NAb) and binding antibody responses, primarily to the vaccine-matched L.P.8.1 variant and other currently circulating variants and lower responses to the ancestral WA1/2020 strain.

(...)

Source: 

Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00050-2/fulltext?rss=yes

____