Tel Aviv – According to a new study, a single dose of the Covid-19 vaccine has been found to provoke a strong immune response in previously infected individuals. If confirmed, these findings could help shape future vaccination policies in the most severely affected countries.
Researchers from Bar-Ilan University and Ziv Medical Center in Israel studied the vaccination of people previously infected with Covid-19 to determine their immune response and compare it to that of people not previously infected with the virus. The study was conducted on a cohort of 514 of the medical centre’s staff members, 17 of whom were infected with Covid-19 anytime between one and ten months before receiving the first dose of the vaccine. Participants’ antibody levels were measured before and after vaccination.
Published in the medical journal, Eurosurveillance, the researchers’ findings showed that the immune response after a single dose of the Pfizer vaccine was particularly strong in people previously infected with Covid-19, irrespective of when they were infected and whether or not they had detectable Covid-19 antibodies prior to receiving the vaccine
“This finding can help countries make informed decisions regarding vaccine policy ― for instance, whether those previously infected should be vaccinated in priority and, if so, with how many doses. It also offers reassurance that not having detectable antibodies after being infected does not necessarily mean that protection following infection is lost,” explains professor Michael Edelstein, who led the study.
The findings of this research also provided evidence that immune response was similar across multi-ethnic groups. This is something particularly welcomed by the scientists, since the virus is known to affect some groups more than others.
The results now need to be confirmed in a larger cohort, the scientists explain. They now plan to continue following their medical centre workers after their second dose of the shot to better understand how long the vaccine will offer Covid-19 protection in different groups of people. ― ETX Studio