One in eight people in the Netherlands could have Covid-19 antibodies as a result of having had the infection, but that does not mean that they should join the back of the vaccine queue to save on scarce vaccines, experts have said.

The figure, based on a continuing probe by blood bank Sanquin, means that as many as 2.3 million people could have developed a natural immunity for the disease for a period of six to eight months. The public health institute has registered almost 900,000 positive coronavirus tests to date.

In total, 13% of 2,000 people who donated blood plasma in the first week of January had antibodies in their blood, as did 15% of people in West Brabant, where the pandemic started last March.

However, this does not mean people with antibodies should hold off getting a vaccine or only receive a single jab of the two-jab vaccine, experts say.

It sounds logical in theory, professor of immunology Marjolein van Egmond told the Volkskrant. ‘But to organise this on a national scale is difficult,’ she said.

‘There are a lot of unknowns, for instance, we don’t know how many antibodies are needed to rebuff the disease or not infect others. It is likely that people who recently had Covid are sufficiently protected but we need to ask if that is the case for the group who had it in spring last year.’

Amsterdam UMC teaching hospital is currently researching whether a single jab would be sufficient for people who already have antibodies.

Halving the dose would save a great many vaccines but, Van Egmond said, the results will not be available in time to adjust the vaccination programme at short notice. ‘And by the time we know more just about everyone is going to be vaccinated anyway,’ she told the paper.