Friday, April 02, 2021
Similarly high immune response
Study: One vaccine dose is enough for those who have recovered
Corona vaccines are still in short supply. Manufacturers such as Biontech / Pfizer cannot keep up with production in view of the high demand. US scientists are now presenting a solution. They find out that one vaccine dose is sufficient for corona patients who have recovered.
For people who have survived severe coronavirus infection, one dose of vaccine will work as well as two. This is the result of researchers in a new US study that appeared in the science magazine “Nature Medicine”. Accordingly, people who have recovered from Covid-19 disease develop a similar antibody response after a dose of the Biontech / Pfizer BNT162b2 vaccine as uninfected people after two doses.
For the study, the research team examined more than 1,000 employees at a California hospital who had been vaccinated with the Biontech / Pfizer vaccine. They measured the antibody levels of the hospital staff for 21 days at different times after the first vaccination.
The result: The 35 people who had gone through Covid 19 disease had a similarly high immune response after one dose as 228 people who had not been infected and had received both doses of the vaccine.
Vaccine for more people
“We found that people previously infected with Sars-CoV-2 developed a vaccine-induced antibody response after a single dose of the BNT162b2 mRNA vaccine, which was comparable to the antibody response after vaccination with two doses in infection-free people,” writes Study author Susan Cheng from Cedars-Sinai Medical Center in Los Angeles. The results support the argument that people who know they are infected can get by on just one dose of the vaccine – which may stretch vaccine supplies so more people can be vaccinated faster.
The researchers therefore recommend that people who have been proven to be infected should only be vaccinated once so that the scarce vaccine supply can be distributed to more people. “This approach could maximize the reach of a limited vaccine supply, potentially allowing millions of people to be vaccinated in the US alone,” said Cheng. Previous studies have also indicated that vaccination increases the effect of the immune response to a natural infection.
So far, the US health authorities and other experts have rejected this approach. They are still convinced that two doses of vaccine are necessary for optimal protection – regardless of whether the vaccinated was previously infected or not.