New vaccine needed by omikron? ‘Virus is probably more resistant’

It is probably already in the Netherlands: the new variant of the corona virus, omikron. The variant was discovered in South Africa, but may have come to our country via various routes.

At the moment, almost all corona patients in the Netherlands still have the delta variant. But if omikron proves to be more contagious than delta, omikron will eventually become dominant.

Do we all need an omikron booster shot? Much is still uncertain.

Fast spread

Whether the vaccines need to be adapted to omikron depends on three things, says Rogier Sanders, professor of virology and experimental vaccinology at the AMC. First, portability.

“Reports from South Africa seem to indicate that the virus is more transmissible than the delta variant, but we have to wait and see.” The number of positive tests in that country suddenly rose rapidly in recent weeks.

The virus has also been found in other countries, especially in southern Africa but also closer to home: Germany, the United Kingdom, Belgium and the Czech Republic. It is 95 percent certain that omikron is also in the Netherlands, says the RIVM.

Second, to what extent does the virus cause milder or more severe disease than older variants? “We don’t know anything about that yet,” says Sanders. If you get sick much less from omikron, it can be good if this variant is more contagious.

The third important question: is the new virus resistant to the immunity that we have elicited from vaccines or from previous infection? In other words: is omikron stronger than our protection? “I think we have to assume that that virus is more resistant,” Sanders says.

The reason for its assumption is that omikron is much more mutated in one important respect than the earlier variants. On the so-called spike protein, with which the virus attaches to human cells, 32 changes have been found compared to the original virus. That is much more than with previous variants.

Current vaccines are specifically designed to produce antibodies that target the spike protein. Still, Marc Kaptein, the medical director of vaccine maker Pfizer Nederland, thinks that his vaccine protects enough against omikron. “Until now, the vaccine has never had to be adjusted. It must be very strange if the new variant is no longer susceptible.”

Sanders is a bit more pessimistic. “We know some of the mutations in omikron in the beta variant, which was less sensitive to the vaccines.”

But, says Kaptein, it is possible that the large amount of mutations makes the new variant weaker. “That may mean that the virus multiplies less well. The beta variant was somewhat less susceptible to the vaccine, but less fit, and has therefore been extinguished.”

New vaccine within 100 days

What if the vaccine doesn’t work well enough? Then Pfizer can deliver a modified vaccine within 100 days, says Kaptein. “We can introduce the genetic code of the new variant into our vaccine. That can be done within weeks.” Sanders agrees: “That’s fairly easy. So that’s good news.”

The next step is testing on humans. “We test on a few dozen volunteers whether the immune response corresponds to what you want,” says Kaptein.

If that is the case, the inspection authorities still have to give approval. “Of course they already know a lot about our vaccine.”

Both vaccine manufacturer Moderna and Pfizer are investigating whether they should indeed adjust their vaccine. Whether everyone really should get an omikron booster shot again depends on the contagiousness and how sick you get from omikron. And the extra protection of the booster shot that we can get now or soon.

Sanders: “With delta we already see that people who have been vaccinated twice do become infected, but that the chance that they end up in hospital is extremely small.”

New vaccine needed by omikron? ‘Virus is probably more resistant’
Source link New vaccine needed by omikron? ‘Virus is probably more resistant’

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