A new study suggests that people who have recovered from Covid-19 may only need one shot of the vaccine. Scientists from the University of California, Los Angeles (UCLA) found that people who had been previously infected with the virus had sufficient immune responses to combat Covid-19 after only receiving one shot of a two-dose vaccine.
They also found that the second shot gave no additional immunity. Findings of the study provide evidence that many more people around the world are protected than previously believed. The study, published in ACS Nano, saw 36 former Covid-19 patients, and 26 people with no history of the virus recruited. Each participant received one shot of either the Pfizer-BiNTech or the Moderna vaccine.
The group with no Covid history all developed antibody levels similar to someone with a mild infection of the virus after getting the first shot and it took two doses to have levels on par with someone who had been severely ill with the virus. Meanwhile, all Covid survivors showed antibody levels similar to someone who had been severely infected after just one dose. Neither did they show an increase in antibody levels after receiving second doses.
Senior author Dr Otto Yang, professor at the UCLA School of Medicine said in a statement, “Our data suggest that a person who previously had Covid-19 has a huge response after the first mRNA vaccination and has little or no benefit from the second dose. It is worth considering changing public health policy to take this into account both to maximize vaccine usage and avoid unnecessary side effects.”