JERUSALEM -- Israeli researchers have found that the antibody levels among people who were infected with COVID-19 shortly after receiving the first vaccine dose remained unchanged despite infection, Bar Ilan University (BIU) in central Israel said on Monday.
Therefore, people tested positive after receiving the first dose should be offered with the second dose, as it provides optimal protection, the team suggested.
The findings are included in a joint study conducted by BIU and Ziv Medical Center (ZMC) in northern Israel and published in the journal Epidemiology and Infection.
The team tracked a cohort of 541 ZMC health care workers, some of whom had already recovered from COVID-19, to determine how those previously infected with the virus responded to vaccination compared to those who weren't infected.
It was found that previously infected individuals who received one dose of the vaccine had much higher antibody levels than fully vaccinated workers who were never infected.
However, infection after the first dose did not increase antibody levels.
Thus, those infected after the first dose while never received the second one had similar antibody levels to those who received one dose and were never infected.
Also, workers infected post-vaccination had antibody levels at 21 and 50 days similar to those never infected who received the same number of doses and much lower than those infected pre-vaccination.