A serendipitous discovery in survivors of the 2003 SARS outbreak offers important clues as to how next-generation vaccines could counter dangerous variants of the coronavirus 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, nearly 20 years ago. Survivors who recently received two injections of Pfizer Inc.’s Covid-19 vaccine developed antibodies that not only blocked the current virus and its variants, but countered related pathogens that could lead to future outbreaks.
“That was really, really unexpected, but an important discovery,” said Linfa Wang, a professor of virology at Singapore’s Duke-NUS School of Medicine and lead author of the paper that compared the immune responses of different groups of patients. The findings were published Thursday in the New England Journal of Medicine.
Wang is working on experimental SARS-based vaccines that could boost the immunity generated by current Covid vaccines to protect against a broader range of SARS-CoV-2 variants and their virological cousins. That includes so-called sarbecoviruses that are sometimes carried by bats, pangolins, civets, and other wildlife, all of which are potential vectors for new infections in humans.
“Based on our data, there is a glimmer of hope that now we can actually develop an effective pan-sarbecovirus vaccine,” which would protect against a number of infections, Wang said via Zoom. “For the first time, maybe we can do something in the context of preparing for a pandemic.”
More research is underway to understand how sequential vaccination can prime the immune system and then boost its response to defend against sarbecoviruses, Wang said. He hopes that patient studies on the new vaccines will begin this year or next.
Additionally, the powerful infection-fighting antibodies produced by SARS survivors vaccinated with Covid may provide the basis for treatments known as monoclonal antibodies, Wang said. They will be further studied and, if successful, could be stored to provide treatment. fast to patients infected with newly emerging sarbecovirus, he said.
The research builds on technology developed by Wang and his colleagues that allows scientists to identify the specific strains of coronavirus that triggered the production of their antibodies. In this way, a simple blood test could determine within an hour which variant a Covid-19 patient was infected with, Wang said. The antibody testing 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 National Research Foundation of Singapore and the National Council for Medical Research.
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