The delta variant of the coronavirus in the United Kingdom now causes 90 percent of the infections there. The variant (also called the ‘Indian variant’ or B.1.617.2) is estimated to be 60 percent more contagious than the alpha variant (the ‘British variant’, B.1.1.7), and is also gaining a foothold in the Netherlands. About 1 percent of all infections here are now with this variant, and the fear is that this could increase quickly because holidaymakers bring it back from Spain and Portugal. How risky is that? Five questions about the delta variant.
1 How far is the delta variant now spread in the Netherlands?
RIVM conducts weekly research into which variants are circulated in the Netherlands. This is done on the basis of a random sample of all positive tests that have come in. The complete sequence of the DNA is read from this, so that it becomes clear which virus variant it concerns.
The most recently available data of this survey cover the first week of June. Then about 95 percent of the positive tests were the alpha variant, which was first discovered in the United Kingdom. More than 1 percent turned out to be the delta variant. That doesn’t seem like much, but the week before it was still half a percent. The variant therefore seems to be gaining ground fairly quickly – it seems, because very hard statements can not yet be made about it. The sample is relatively small, 600 tests that were administered at the beginning of June have been examined for the time being. That number will grow to about 1,500 in the coming weeks, the results will trickle in over a few weeks. Those initial results included seven positive tests of the delta variant. Because the numbers are so small, there are large margins of uncertainty.
What is worrisome: the variant is also found in people who have not traveled or have been in contact with someone who was, for example, in India or the United Kingdom. This means that people also become infected within the Netherlands, and it is therefore spread more widely among the population.
2 Do vaccines also protect against the delta variant?
Yes, the first studies by Public Health England among vaccinated Britons suggest that a full vaccination, i.e. with two doses, is still great protection against symptoms, and very good protection against hospitalization by the delta variant. There is no data yet on protection against death from Covid-19.
The British studies compared the effect of Pfizer’s and AstraZeneca’s vaccines against the alpha and delta variants. The protection against infection with symptoms by the delta variant is slightly less effective than that against alpha: Pfizer’s vaccine was 88 percent effective two weeks after the second shot (against alpha that was 93 percent), that of AstraZeneca 60 percent (against alpha 66 percent). But against hospital admission due to the delta variant, protection after full vaccination was still high: 96 percent for Pfizer, 92 percent for AstraZeneca. There are no data yet on Moderna’s vaccine, but it is expected that the protection provided by this vaccine is comparable to that of Pfizer.
In the Netherlands, a quarter of adults are now fully vaccinated, 45 percent have had one dose.
3 Are you also protected against the delta variant after the first injection?
Three weeks after the first shot, these vaccines do not yet protect well against getting sick from delta, but they do protect against hospitalization. The immune system needs a few weeks to build up anyway, that applies to all vaccines and virus variants. Three weeks after the first injection, the protection of both vaccines was roughly 50 percent against symptoms caused by variant alpha. That protection is significantly lower against delta: 33 percent.
But one dose of Pfizer’s vaccine protected 94 percent after three weeks, and AstraZeneca’s 71 percent against hospitalization from the delta variant, data from Public Health England showed.
Nothing is yet known about the protection against the delta variant by Janssen’s vaccine, of which only one dose is given. This has only been in use in the UK since 28 May. It is therefore too early to make any statements about this, a Janssen spokesperson said. Publications with the first results on this are on their way.
One shot is therefore not sufficient against this variant. The long time of twelve weeks between doses that the UK used until recently may have contributed to the rapid emergence of the delta variant there. The British have it now scaled back to eight weeks. So far, nearly 80 percent of Britons have had one shot, and 58 percent have had two. But also the relatively late introduction of travel restrictions from India play a role in the rapid rise, as do large groups of still unvaccinated young people and people in deprived areas, such as in the current hotbed in the Manchester region.
In the Netherlands, the group of people between 60 and 65 years who received the AstraZeneca vaccine is only now ready for the second shot. And only half of all people in their fifties have received the first shot.
4 Do people get sicker after infection with the delta variant?
That can’t be said yet. The symptoms seem milder, but that could also be because mainly younger people are now infected, with Covid-19 usually being milder. According to epidemiologist Tim Spector of King’s College London, who is leading a study of covid symptoms reported by app, the top four most reported complaints changed. Headaches, sore throats, a runny nose and fever now top the list, while coughing and loss of smell are less reported.
In a Scottish study that Monday in The Lancet popped up, the researchers did see that the risk of ending up in hospital was two times greater for the delta variant compared with alpha. Especially for people with multiple underlying conditions, the risk was higher.
In India, where the delta variant is widely circulated, doctors see an increase in Covid-19 patients who subsequently develop diabetes. However, it is not yet possible to say whether this increase is specifically due to the delta variant. Before the emergence of worrying variants, scientists suspected that the SARS-CoV-2 virus can cause diabetes in some patients. Diabetes is very common in India, due to genetic predisposition and a poor lifestyle: nearly 68 million people have diabetes – only in China there are more.
5 Does the delta variant affect the Dutch relaxations?
In January, Prime Minister Mark Rutte (VVD) and Minister Hugo de Jonge (Public Health, CDA) quickly warned against the British variant, which is now called alpha. That is a lot more contagious than the virus that was circulating in the Netherlands until then, and that is why extra measures had to be taken, was the message. The curfew was also introduced.
This time a completely different sound is heard from the Binnenhof. De Jonge told journalists yesterday that new relaxations can continue because the number of Covid patients in hospital continues to fall and vaccinations are now being carried out quickly. Every measure is looked at, he said. He speculated, among other things, about the abolition of the mask obligation and even the basic measures, such as keeping distance and working from home, would be “reweighed”.
RIVM is concerned about the Delta variant. Chantal Reusken, who monitors the development of the different variants at RIVM, suggested on Twitter on Wednesday it is precisely that compliance with the basic measures is extra important because the delta variant appears to be more contagious. RIVM also calls on young people who have been to Spain or Portugal to be tested, even if they have no complaints. There is a fear that they were infected with the delta variant while on holiday, for example by British tourists.