A single shot of one of the currently authorized Covid-19 vaccines may be enough to provide immunity to individuals who have previously been infected by the virus.
As more people get vaccinated each day scientists are learning that not only is it safe to wait longer for the second dose of the Covid-19 vaccine but new research shows that people who’ve already been infected by the virus might only need a single shot of the vaccine. The study, published in the New England Journal of Medicine, looked at 109 people with and without previous SARS-CoV-2 immunity. What they found was that those who had already contracted Covid-19 developed antibodies within days of the first dose of vaccine at a rate 10 to 20 times higher than those who were uninfected, and at a more than tenfold rate after the second dose. “We showed that the antibody response to the first vaccine dose in people with pre-existing immunity is equal to or even exceeds the response in uninfected people after the second dose,” said co-author Viviana Simon in a statement. “For that reason, we believe that a single dose of vaccine is sufficient for people who have already been infected by SARS-CoV-2 to reach immunity.” “These findings suggest that a single dose of vaccine elicits a very rapid immune response in individuals who have tested positive for COVID-19,” added Florian Krammer, co-author and professor of vaccinology. “In fact, that first dose immunologically resembles the booster (second) dose in people who have not been infected.
