Coronavirus Vaccines to Trigger Superimmunity in People

A related and much more fatal Coronavirus sowed terror over 20 years before SARS-CoV-2, killing about 10% of the 8000 persons who became afflicted. However, the severe acute respiratory syndrome (SARS) outbreak in 2003 may have left some survivors with a gift. Former SARS patients who were vaccinated against COVID-19 appear to be able to fight off all SARS-CoV-2 variants currently in circulation, as well as ones that may emerge shortly, according to a recent study.

Their potent antibodies may also defend against Coronavirus in other species that have yet to infect humans—and may hold the key to developing a pan Coronavirus vaccine to prevent future epidemics. Eight SARS survivors were recently given two doses of a messenger RNA COVID-19 vaccine, according to a team lead by emerging disease specialist Linfa Wang from Duke-NUS Medical School in Singapore.

Wang and colleagues report today in The New England Journal of Medicine that antibodies sieved from their blood effectively “neutralised” an early strain of SARS-CoV-2 as well as SARS-CoV, the virus that caused SARS, in a test tube. The researchers also discovered that these neutralising antibodies were effective against the SARS-CoV-2 Alpha, Beta, and Delta versions, as well as five similar Coronavirus identified in bats and pangolins that might infect people.

The discovery of broad spectrum immunity against sarbecoviruses—a subset of Coronavirus that includes the viruses that cause SARS and COVID-19—is “amazing and very good news,” according to Priyamvada Acharya, a structural biologist at Duke University who works on pan Coronavirus vaccine research but was not involved in the new study.Both SARS-CoV and SARS-CoV-2 infect humans when their surface protein, spike, attaches to the human cellular receptor angiotensin-converting enzyme 2. (ACE2). So Wang was taken aback when other researchers revealed last year that persons who had recovered from SARS had antibodies that could stop SARS-CoV from binding to the ACE2 receptor, but not against SARS-CoV-2.