Twice a year jab: ‘Not desirable, but good to prepare for’

The booster campaign in the Netherlands is slowly but surely getting underway. All over 18s who wish to do so must have received an invitation for a third shot (or second shot, in the case of Janssen) by 7 January.

But what happens after that? Will there be a fourth, fifth, perhaps sixth visit to the vaccination site? Outgoing Health Minister De Jonge said in a parliamentary debate yesterday that he assumes “we still have a number of shots to go”.

It is still unclear when the first possible next shot should be made, although the minister hinted at the second quarter of next year. An adapted corona vaccine is then expected to be available that protects better against the omikron variant. “As soon as it becomes available, we will buy it too. In fact, we have it already ordered“, said De Jonge. He also said that everything is aimed at “that we are able to set that new shot in the second quarter”.

Effect boostercampagne

It is difficult to say whether this will ultimately be necessary, immunologists emphasize. “That’s the difficult thing with vaccines: you only know afterwards how long they protect,” says Marjolein van Egmond of the Amsterdam UMC. According to the immunologist, we can only say something about the next injection once more is known about the effects of the current booster campaign, which has only just started.

“Does the amount of antibodies decrease just as quickly after the third injection as after a second injection?” she wonders, among other things. “Or does such a booster provide longer protection? That makes quite a difference. Then a fourth injection might not be necessary, or only later.”

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