SARS Survivors Offer Clues on Protecting Against Future Scourges
(Bloomberg) -- A serendipitous discovery in survivors of the 2003 SARS outbreak offers important clues about how next-generation vaccines might counter dangerous coronavirus variants now and protect against future pandemics.
The signs were found in the blood of people who contracted the virus that causes severe acute respiratory syndrome, or SARS, almost 20 years ago. Survivors who recently received two shots of Pfizer Inc.’s Covid-19 vaccine developed antibodies that not only blocked the current virus and its variants, they countered related pathogens that could spawn future outbreaks.
“That was really, really unexpected, but an important discovery,” said Linfa Wang, a professor of virology at Singapore’s Duke-NUS Medical School and the lead author of the paper that compared the immune responses of different patient groups. The findings were published Thursday in the New England Journal of Medicine.
Wang is working on experimental vaccines based on SARS that could bolster the immunity generated by current Covid shots to protect against a broader array of SARS-CoV-2 variants and their virological cousins. That includes so-called sarbecoviruses sometimes carried by bats, pangolins, civets and other wildlife -- all potential vectors for novel infections in humans.
“Based on our data, there is a glimpse of hope that now we can really develop an efficient pan-sarbecovirus vaccine,” which would protect against an array of infections, Wang said over Zoom. “For the first time, maybe we can do something in the context of pandemic preparedness.”
More research is underway to understand how sequential vaccination is able to prime the immune system and then boost its response to defend against sarbecoviruses, Wang said. He hopes patient studies on the new shots will begin this year or next.
In addition, the potent infection-fighting antibodies produced by Covid-vaccinated SARS survivors may provide the basis for treatments known as monoclonal antibodies, Wang said. They will be studied further and, if successful, could be stockpiled to provide rapid treatment for patients infected with newly emerging sarbecoviruses, he said.
The research builds on technology developed by Wang and his colleagues that lets scientists identify the specific coronavirus strains that triggered production of their antibodies. In this way, a simple blood test could determine within an hour what variant a Covid-19 patient was infected with, Wang said. The antibody analysis technique could also be used to identify early cases of Covid-19 and potentially the progenitor of SARS-CoV-2, he said.
The study was supported by grants from the Singapore National Research Foundation and National Medical Research Council.
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