Vaccines and effectiveness: what protects against Omikron?

Status: 10.12.2021 4:57 p.m.

How effective are the vaccines against the Omikron variant? How long would it take to adjust them? The first results of preprint studies and tests are available. What do they say, what don’t they say?

By Stefan Troendle, Ralf Kölbel and Carla Vinetta Richter, SWR

The omicron virus variant, also known as B.1.1.529, which was first detected in Botswana at the end of November 2021 and later mainly in South Africa, also appears to be spreading further in Germany.

The many mutations in the new Corona variant, including on the spike protein, are particularly worrying. This protein is responsible for allowing the virus to penetrate human cells and infect them. The vaccines also work with the spike protein. The body is made to develop antibodies against this very spike protein. Then the immune system can defend itself against the virus in the event of an infection. How well the current vaccines work against the variant has now been examined for the first time.

How well do the available vaccines work against the new variant?

the Effect of the available vaccines against the Omikron variant examined the Frankfurt virologist Sandra Ciesek. First result: Probably all currently available Covid-19 vaccines no longer protect so well against infection with the omicron variant of the coronavirus. Ciesek and her team have found out that even people who have been vaccinated twice are hardly safe from infection with Omikron.

Samples from people who were vaccinated twice with BioNTech or twice with Moderna or with once AstraZeneca and once BioNTech were examined. After six months, they were not protected from infection with this variant: the antibodies present could not neutralize the virus.

Anyone who has been vaccinated three times with BioNTech still has little protection: 25 percent effectiveness based on the infection, says virologist Ciesek. With the Delta variant, it is 95 percent. It is not yet known how meaningful these results are, that is, how many samples it examined.

Are there more breakthrough infections?

It could well be that with Omikron even more breakthrough infections will be seen and thus the incidences will rise again significantly, says Carsten Watzl, Head of the Immunology Research Department and Scientific Director, Leibniz Institute for Labor Research at TU Dortmund.

The founder of BioNTech, Ugur Sahin, also assumes that a new vaccine against the variant will be necessary at a certain point in time. The group’s first laboratory tests had shown that two doses of vaccine might provide less protection against infection with Omikron. However, one is still armed against a severe course of Covid disease. Three doses of the BioNTech vaccine would die However, neutralize the omicron variant, according to the result of the first two-week examination.

How long does it take to adapt the vaccines to the new variant?

In the past few months BioNTech, Moderna and AstraZeneca have already practiced in the laboratory how to adapt their vaccines to variants such as Beta and Delta. Sahin says it will take around 100 days before a new vaccine against the variant can be developed and delivered.

However, the pace of development differs depending on the vaccine technology – it ranges from six weeks to a few months. In the case of mRNA vaccines, a changeover is possible at short notice, in the case of vector vaccines it takes longer. Because with this technology, new viruses must first be grown and that extends the development time to around three to four months, say the President of the Paul Ehrlich Institute (PEI) Klaus Cichutek and the Hamburg vaccination researcher Marylyn Addo at a press conference at the Science Media Center. The actual production would then probably also take another six weeks.

STIKO boss Thomas Mertens assumes that it will take a few more months before the vaccines are actually available. For mRNA vaccines, it should take three to four months from the decision to adapt to approval. With the vector vaccines, probably a month longer.

This means that the new vaccines could not be ready until late spring 2022 at the earliest, but no later than autumn. (Source: ORF Science)

How well do new vaccines like those from Novavax or Valneva protect against Omikron?

New vaccines from Novavax or Valneva could also soon be approved in the EU. Do these protein-based vaccines – often referred to as “dead vaccines” – also help against the omicron variant? Florian Krammer, vaccine expert at the Icahn School of Medicine at Mount Sinai in the USA, expressed concern: “I would assume that the effectiveness of the immune response is the greatest decrease in you when you are vaccinated.”

According to Krammer, inactivated vaccines are not so well suited to triggering a T-cell reaction and also produce fewer neutralizing antibodies. But it is important to be able to rely on various responses from the immune system in the event of an infection.

What can you do in the meantime?

Various steps can be taken to avoid infection and spread of the Omikron variant. First of all, you should still make sure to wash your hands regularly, avoid touching your face, keep your distance from others, especially in closed rooms, and wear a medical mask. If possible, avoid large crowds or have limited contact with the same people.

In addition, Leif-Erik Sander, head of the Infection Immunology and Vaccination Research Research Group at the Charité in Berlin, recommends a booster vaccination. A booster vaccination (usually a third vaccination dose) stimulates the immune system to produce antibodies again.

If you do get infected, how does an Omikron infection work?

Little is currently known about the course of the disease when infected with the new Omikron variant: Angélique Coetzee, chairwoman of the South African Medical Association, told the BBC that the cases so far found in her country were not serious. However, the investigations into this variant are still at a very early stage. Here you have to take into account that the population in South Africa is on average significantly younger than in Germany, for example.

Coetzee told the Telegraph newspaper that one had to worry that the new variant could hit older people who also suffered from diabetes or heart disease much harder. The virologist Christian Drosten and the new Health Minister Karl Lauterbach also see no reason to give the all-clear with regard to Omikron.

With regard to severe or fatal courses in vaccinated people, most researchers have so far assumed that protection will not decrease as much here – but more details are not yet known.

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