A survey of COVID-19 testing in hospitals shows that tests came back positive almost three times more often among the unvaccinated staff and that a booster shots provides special protection, the Croatian Institute of Public Health said on Friday.

The survey was aimed at establishing the difference in positive PCR and rapid antigen tests between fully vaccinated healthcare workers and those not vaccinated.

The survey covered 1,371 workers in 12 hospitals, of whom 831 were vaccinated (60.61%) and 540  were unvaccinated, and 3.95 tests were done per worker on average.

Among those vaccinated, 57 were positive (6.86%), while among those not vaccinated, 101 were positive (18.7%).

Out of 475 workers who received a booster shot at least two weeks before being tested, 24 were positive (5.77%), while out of 265 who did not receive it, 30 were positive (11.32%).