2 July 2026 

COVID-19 vaccine boosters not only protect against SARS‑CoV‑2 – the virus behind the most recent pandemic – but may also help protect against some future coronaviruses that risk spreading from animals to humans, Cambridge researchers, supported by NIHR Cambridge BRC, have shown.

In a related study, the team has shown that an individual’s first exposure to SARS‑CoV‑2 ‘locks in’ their immune response, impeding their ability to respond to future variants, even when vaccinated.

When an individual is infected with a virus, the immune system produces antibodies that will recognise the virus if it re-enters the body and prevent infection taking hold again. Vaccination works on the same principle.

A team led by scientists in the Gupta and Rihn laboratories at the Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), University of Cambridge, asked whether the vaccines currently given against COVID-19 might also protect us against future coronaviruses that risk ‘spilling over’ from animals to humans.

In findings published yesterday in the journal npj Vaccines, the team studied blood samples from older UK adults (average age around 69) who had received four COVID‑19 vaccine doses, including a recent bivalent booster that included both the original Wuhan strain and the Omicron variant.

They tested how well antibodies in these blood samples could neutralise different Omicron variants of SARS‑CoV‑2. They also tested the antibodies to see if they could neutralise the SARS‑CoV‑1 virus – responsible for the 2003 SARS outbreak – and a range of closely-related coronaviruses (known as ‘sarbecoviruses’) found in bats and pangolins, some of which are considered potential threats for future outbreaks.

As expected, antibodies worked less well against newer Omicron variants than against the original Wuhan strain, showing how the virus has evolved to escape the immune response. The antibodies were poor at neutralising SARS‑CoV‑1, which is genetically more distant.

Surprisingly, the antibodies were much better at neutralising two sarbecoviruses closely related to SARS‑CoV‑2 – one from bats and one from pangolins – than they were at neutralising the original Wuhan strain itself, even though these two viruses have never infected humans. Several of the bat and pangolin viruses tested have the ability to enter human cells and are genetically close enough to SARS‑CoV‑2 to raise concern about future spillovers.

Grace West from CITIID, the study’s joint first author, said: “We’d expect the COVID vaccine to offer protection against today’s variants, but we were surprised to find that it also provides protection against some animal coronaviruses with future pandemic potential.”

Rebecca Morse, also a joint first author from CITIID, said: “We may already have a head start when it comes to protecting against certain future outbreaks. Boosters could reduce both severity and spread if spillover were to occur, buying us vital time while we develop a more targeted vaccine. This will be particularly important for older and vulnerable populations, who are usually hardest hit in new pandemics.”

The researchers say their findings could inform next‑generation vaccine design. Vaccines that target parts of the coronavirus spike protein common to multiple viruses could protect against related viruses. The spike protein is a key element of the virus that the immune system recognises.

The research was funded by Wellcome and the Medical Research Council, with additional support from the Hong Kong Jockey Club, National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre and Addenbrooke’s Charitable Trust.