About a million Slovaks do not have any antibodies to Covid-19

About a million Slovaks do not have any antibodies to Covid-19, which is half of unvaccinated people, a first such Slovak study showed. Less than half of the recovered had moderate or high levels of antibodies. The level of antibodies decreases rapidly and if low does not protect against the omicron variant. In the better vaccinated UK, only 5% of people do not have antibodies.