University news

Global immunity to COVID-19 is likely to offer protection against the emergence of an as yet undiscovered new SARS-type virus, dubbed SARS-CoV-X, ultimately lowering the risk of a future coronavirus pandemic.

The findings come from a new study, led by researchers at the MRC-University of Glasgow Centre for Virus Research, which used information from real-world patient antibody samples combined with mathematical modelling to better understand the levels of immunity against SARS-like viruses in the global population.

The research team found that, as well as high levels of specific immunity to SARS-CoV-2, the virus responsible for the COVID-19 pandemic, the population also had cross-protection immunity against a range of sarbecoviruses, the wider family of viruses that SARS-CoV-2 belongs to.

Infections by endemic viruses – viruses that circulate commonly in the general population – and the vaccines used to control them, often provide cross-protection immunity against related viruses. This cross-protection can potentially alter the transmission dynamics of new zoonotic viruses with pandemic potential, and even the likelihood of their successful emergence.

Now, researchers at the MRC-University of Glasgow Centre for Virus Research have been able to demonstrate that the likelihood of the emergence of a new sarbecovirus has been reduced significantly as a result of population-wide immunity to SARS-CoV-2.

Researchers found that COVID-19 immunity, both from infections during the pandemic and vaccinations, may also protect against sarbecoviruses that have not been discovered yet. They suggest this broader immunity may be key to slowing down – or stopping – a future pandemic by a previously unknown sarbecovirus.

Professor Pablo Murcia, Professor of Integrative Virology from the MRC-University of Glasgow Centre of Virus Research, said: “Our global experience with COVID-19 has generated a biological barrier to other coronaviruses. While this does not mean we are immune to all future threats, infection and vaccine-derived immunity to SARS-CoV-2 has made it much harder for other sarbecoviruses to start the next pandemic.

“Our study shows the circulation of SARS-CoV-2 in the general population, alongside global vaccination campaigns, generated widespread immunity against related sarbecoviruses, creating an ‘immunity shield’ against the emergence of a novel sarbecovirus in humans.

The team were also able to show that preventative vaccination campaigns against any potential new sarbecovirus SARS-CoV-X,using currently available COVID-19 vaccines, could also help to slow or stop global spread.

Brian Willett, Professor of Viral Immunology at the CVR, added: “Our results suggest that our current vaccines might be effective against the emergence of a new coronavirus. Our mathematical models strongly suggest that the use of existing COVID-19 vaccines against any new and emerging sarbecoviruses reduced the chance of sustained transmission.

“We found that current vaccines would be most beneficial if implemented soon after the first SARS-CoV-X case was found. By contrast, delays in implementing any preventative vaccination would likely reduce its effectiveness.”

Identifying viruses with zoonotic potential before they emerge is essential for pandemic preparedness. However, to infect humans zoonotic viruses must overcome multiple biological barriers, including being able to sustain human-to-human transmission. One of the hardest barriers for a new virus to overcome is pre-existing immunity or cross-protection immunity in the wider population.

The study, ‘Post-pandemic changes in population immunity have reduced the likelihood of emergence of zoonotic coronaviruses’ is published in Nature Communications. The work was funded by the UKRI Medical research Council (MRC), and the UKRI Biotechnology and Biological Sciences Research Council (BBSRC).

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Enquiries: ali.howard@glasgow.ac.uk or elizabeth.mcmeekin@glasgow.ac.uk

First published: 24 March 2026