What can the Netherlands expect in the booster field?

In Rotterdam, the GGD is carrying out a series of booster vaccinations this week in which children can watch while the mothers receive their shot.Statue Guus Dubbelman / de Volkskrant

To what extent are the extra booster laps necessary?

First and foremost: whether so many injections are needed is still unclear. With the provisional estimate of three new rounds, outgoing minister De Jonge mainly opts for certainty. In order to have at least enough vaccines in stock, the minister buys in bulk. The Netherlands orders almost 6 million extra vaccines, in total almost 29 million vaccines have been purchased.

Those extra boosters may be needed to maintain protection against the virus. The ministry is examining the extent to which this is the case together with the RIVM. The first results of an ongoing British study show that the effect of the booster may decrease by 15 to 25 percent after ten weeks. It is only about protection against symptoms. A booster probably still protects very well against serious illness and hospitalization, the British expect.

‘It is wise to prepare the Netherlands for all possible scenarios,’ says André Knottnerus, professor of general practice and former chairman of the Health Council. ‘We do not yet know what consequences omikron will have in the near future. In addition, a new variant may emerge. You’d better buy now, otherwise it’ll be too late.’

Does the booster campaign ever end?

It is indeed possible that a few more shots will follow after this booster round, thinks Ben van der Zeijst, emeritus professor of vaccinology. ‘Boosters always decrease in effectiveness, a new round helps against that. And once the boosters have been adapted to the omikron variant, they provide even more benefits.’

Van der Zeijst does not think that the whole of the Netherlands will continue to boost in eternity. “There will come a time when the virus will no longer overload healthcare,” he says. ‘We already had that situation with existing coronaviruses. They come back once every eighteen months, make people sick, but do not lead to disruption. Boosting is then no longer necessary.’

An annual booster may well be needed for the frail and the elderly, Knottnerus says. ‘I see that as the most likely scenario: that we vaccinate risk groups every year, just like with the flu shot. You should think of a jab in the autumn to offer some extra protection.’

Are there any risks associated with additional vaccinations?

There is nothing to indicate that, says Willem van Eden, immunologist. ‘It’s quite rare to have that much pricking, but there are no significant risks associated with it. A lot has also been boosted, including in Israel where they started earlier. This does not show that multiple injections lead to a higher risk of side effects. There is also no indication that administering multiple boosters leads to a violent reaction of the immune system, it actually strengthens that immune response.’

The question is whether frequent boosting makes sense. ‘The more often you inject, the less effective a booster is’, says Van Eden. ‘That is what you generally see with vaccines, although this is not the case with our current booster campaign. For the time being, the effect is considerable.’

Do the Dutch want those boosters?

Half of the questions to the Doubt Phone, set up to provide information to vaccine doubters, are about the booster. That’s telling. The enthusiasm for the current round of injections seems to have diminished somewhat. A survey by the RIVM at the end of November shows that not everyone who took the first and second injection is prepared to get a third: another 87 percent say they will do so. Especially among young people aged 16 to 24, the willingness to vaccinate has fallen sharply, to 63 percent.

If there are indeed new rounds of injections, it is likely that this willingness will decrease further, thinks professor Knottnerus. ‘Last year people thought: I’ll take those two shots and then hopefully it’ll be over. Now that this is not the case, it is difficult to motivate people. That requires communication, you have to explain well why a new round is needed, that it is safe to take the booster. This must be done in parallel with a possible new booster campaign.’

In some countries, less than 10 percent of the population is vaccinated. Is it morally justifiable to think about extra boosters here?

Extensions to booster campaigns could actually prolong the pandemic, WHO director-general Tedros Adhanom Ghebreyesus warned last week. According to Ghebreyesus, if boosting means that fewer vaccines become available for poor countries, mutations and new variants can arise there.

That needs nuance. Italian researchers saw that after more than two months of lab experiments, coronaviruses became ‘completely resistant’ to blood plasma with antibodies. This indicates that variants evade immunity and that mutations therefore also arise in areas with a higher vaccination coverage.

And even if it’s not enough, countries do give vaccines to developing countries. The Netherlands aims to donate one for every injection given. The outgoing cabinet wanted to give away more than 27 million vaccines last year. That is not easy in practice, by the way: at the beginning of December 5 million had been donated.

In any case, it is important that the Netherlands does not lose sight of developing countries, says Knottnerus. ‘As long as there are areas with a vaccination coverage of well below 50 percent, we will in any case maintain the virus unabated. This is an important task for governments and industry.’