People with Prior SARS-CoV-1 Infection May Have Stronger Response to COVID-19 Vaccines

Infection with prior coronaviruses may provide more durable protection against COVID-19, according to a recent research letter that offers insight into possible new vaccine strategies.

Investigators in Taiwan examined antibody levels after vaccination with the AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19) in health care workers who previously were infected with SARS-CoV-1, which was responsible for an outbreak of severe acute respiratory syndrome in 2003, compared with those who weren’t previously infected.

A research letter, published in JAMA Internal Medicine, detailed the study, which included 340 health care workers at Kaohsiung Chang Gung Memorial Hospital who received the AstraZeneca COVID-19 vaccine, including eight participants who previously were infected with SARS-CoV-1.

“After 1 ChAdOx1 dose, the geometric mean of anti–SARS-CoV-2-spike RBD antibody levels were significantly higher in those with prior SARS-CoV-1 infection (4441.2 U/mL; 95% CI, 2337.8-8437.3) than in those without prior infection (65.0 U/mL; 95% CI, 59.0-71.7) (P < .001) and in uninfected individuals who had received 2 ChAdOx1 doses (517.4 U/mL; 95% CI, 383.0-699.0) (P < .001),” the authors, led by Yi-Chun Chen, MD, of Kaohsiung Chang Gung Memorial Hospital in Taiwan wrote.

Blood samples were taken at least four weeks after vaccination between June and July 2021. The median time between vaccination and measurement of antibodies was significantly longer among those who had prior SARS-CoV-1 infection at 59 days compared with a median time of 46 days for those without prior infection.

Participants who received one dose of the AstraZeneca vaccine included seven who had previous SARS-CoV-1 infection and 295 who didn’t have previous infection. Those receiving two doses of the vaccine included one who had a prior infection and 37 who didn’t. None of the participants had SARS-CoV-2 infection.

Those with prior SARS-CoV-1 infection were older, with a median age of 45.8 compared with 36.3 for those without prior infection.

“Immunological memory is the key point to gaining insights into the likelihood of the durability of protective immunity against SARS-CoV-2 infection,” the authors wrote. “Accruement of a heterogeneous repertoire of memory cells is crucial for the rapid development of protective immunity following reinfection. In this article, we offer a potential proof of concept for a novel vaccine that targets SARS-CoV-1 and SARS-CoV-2 spike glycoproteins to establish durable, protective immunity against SARS-CoV-2 and other sarbecoviruses.”

The results are consistent with previous research showing cross-reactivity to SARS-CoV-2 nucleocapsid in people with prior SARS-CoV-1 infection, the authors noted.

In one previous study, investigators and Northern Arizona University demonstrated that COVID-19 could trigger antibodies that were originally generated in response to infection by older coronaviruses.

Another study suggested that cross-reactive coronavirus antibodies could aid the creation of vaccines or therapies that are effective against a wide range of coronaviruses.