Corona Vaccines: The Means of Choice


Status: December 28, 2021 1:11 p.m.

Five vaccines have now been approved in the EU. With the vaccine from the manufacturer Novavax, a protein-based preparation is also among them for the first time. What are the advantages of which vaccine?

Hope came during the Christmas season: a year ago, the first vaccination against the corona virus was administered in Germany. In Halberstadt in the Harz Mountains, Edith Kwoizalla, the 101-year-old resident of a nursing home, received the first dose on Christmas Day.

More than 61 million Germans have now been vaccinated. Still not enough – a hard core continues to vehemently reject the vaccination against Corona. With the protein-based vaccine Nuvaxovid from the manufacturer Novavax, the European Medicines Agency (EMA) has approved the fifth vaccine against corona.

A game changer? “It would be my great hope that the unvaccinated over 60 can now make better friends with the protein-based vaccine,” says the President of the German Society for Immunology, Christine Falk.

They all rely on the spike protein

For a long time, the mRNA vaccines from the manufacturers BioNTech / Pfizer and Moderna were the beacons of hope. You were the first to receive the green light in the EU. It was a breakthrough for the technology, but research into mRNA vaccines has been going on for more than 20 years. With them, as with the other approved vaccine types, the focus is on a certain surface molecule of the coronavirus, the so-called spike protein.

The spike protein sits on the outer shell of the virus, but is not itself infectious. The mRNA, the genetic “blueprint” for this protein, is artificially produced in the laboratory. This enables the body to independently generate the spike protein, which is then recognized by the immune system. It activates defense cells and forms antibodies. If an infection occurs later, the body recognizes the spike protein and fights it.

The vector vaccines from the manufacturers AstraZeneca and Johnson & Johnson also rely on the genetic blueprint of the spike protein. However, they are based on defused cold viruses that are harmless to humans and act as transporters for the mRNA of the spike protein. With this approach, too, the body rebuilds the proteins itself.

Genetic changes excluded

The AstraZeneca vaccine is no longer inoculated in Germany. The approval studies had already shown a lower level of vaccination protection compared to the mRNA preparations at the beginning. In addition, there were very rare sinus vein thromboses in young people in connection with the vaccination. In the meantime, demand fell sharply. Vaccination with the Johnson & Johnson vaccine has also become controversial. According to the Robert Koch Institute, the one-time vaccination only prevents a severe course by 65 percent.

The mRNA and vector-based vaccines are attached to the concern of some people that they could change the genetic information. According to immunologist Falk, however, this is impossible. “The mRNA cannot penetrate the cell nucleus at all. With vector vaccines there is theoretically the possibility, but the probability that this will happen is almost zero.”

A new type of vaccine

With the vaccine Nuvaxovid from the manufacturer Novavax, another type of vaccine has now received approval from the EMA. Protein-based vaccines do not contain any genetic information about the protein, but in the case of the corona vaccine the spike protein itself – as a synthetic replica.

The body does not have to recreate the protein on its own; one step is, as it were, skipped. However, this also makes the vaccination reaction less pronounced. The vaccine therefore contains a so-called adjuvant – a type of catalyst that has nothing to do with the active ingredient, but enhances its effect and smuggles the spike protein into the cells. Novavax relies on the active enhancer Matrix-M, a relatively new active ingredient that is obtained from the bark of Chilean soap-bark trees. Due to the long experience with active enhancers in protein-based vaccines, the procedure is very safe, even if the substance itself is new, according to immunologist Falk.

The effectiveness of Novavax against the early virus variants was around 90 percent in the manufacturer’s clinical studies. New studies now show that Novavax can also be used as a booster vaccination. The EU Commission has ordered 100 million vaccine doses. From January four million cans are to be available in Germany, according to the Federal Ministry of Health there are no exact delivery dates.

Not a classic “dead vaccine”

Some people had long expected Novavax to be the first approved “dead vaccine” to be traded. However, Novavax is not a dead vaccine in the classic sense. To do this, the vaccine would have to contain the entire virus, which was previously grown up in virus cell cultures and then killed and inactivated. Novavax, on the other hand, only contains the spike protein of the virus, which is artificially produced in insect cultures. A classic vaccine is currently also being tested by the EMA: the vaccine from the French manufacturer Valneva.

Since protein-based vaccines such as Novavax have been used for a very long time, the vaccine could take away the skepticism of some undecided people, for which there is no scientific justification. There are already many vaccines based on this technology, “but if you look at how many billions of people worldwide have been vaccinated with the mRNA and vector-based vaccines and how well this has been documented, the mRNA and vector-based vaccines are by far Security at least equaled, “says immunologist Falk.

How the vaccinations against Omikron work

Despite a double vaccination, even despite the booster, people are currently infected with the Omikron variant. But that does not mean that the vaccines that have been approved so far are not working. “In general, three lines of defense are activated during a vaccination: antibodies in the oropharynx, antibodies in the blood and the T cells in the lymph nodes. Only the first line of defense does not work well against Omikron. The antibodies in the oropharynx are sufficient not enough to avoid infection, “says immunologist Falk.

A vaccination protects against severe disease very well. That is why everything must now be done to ensure that the boost is boosted as quickly as possible – and that more people still opt for a primary vaccination. Meanwhile, vaccine manufacturers are working on a vaccine variant adapted to Omikron. Waiting for it currently makes no sense, says the expert: With the previous vaccines, very good immunization is still possible.

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