A fifth Covid-19 vaccine comes onto the market in the European Union.

The European Medicines Agency (EMA) gave the green light to the vaccine from the American biotech company Novavax.

The responsible EMA committee recommended conditional approval on Monday.

The European Commission still has to make the final decision, but it is a matter of form.

The agent is a protein-based vaccine with virus antigen. Specifically, Novavax uses the so-called spike protein of the Covid-19 pathogen Sars-CoV-2 for its vaccine and reproduces it en masse in insect cells. After vaccination, the human immune system uses it to generate antibodies against the protein and can thus fight off Covid 19 disease. 

So far, the mRNA vaccines from Biontech / Pfizer and Moderna as well as the vector vaccines from Astrazeneca and Johnson & Johnson have been approved in the EU to protect against the coronavirus.

With the Novavax vaccine, people in the EU would get a different type of corona vaccine to choose from.

This could be of interest to people who have reservations about the vaccines that have been approved to date or who have medical reasons against their use.

Unlike the corona vaccine from Biontech / Pfizer vaccine, for example, the Novavax vaccine can be stored at refrigerator temperature.

This makes logistics easier and makes the product interesting for poorer countries as well.

How well does Novavax protect against Omikron?

Novavax announced in June that its corona vaccine was around 90 percent effective.

It also protects against virus variants and 100 percent against "moderate and severe" disease courses.

How well exactly the agent protects against the coronavirus variant Omikron, which was only discovered at the end of November, is unclear, however. 

A booster dose with the vaccine from Moderna significantly increases the body's immune defense against the new Corona variant Omikron, according to the manufacturer.

Compared to a double vaccination, the neutralizing antibody level increased by around 37 times after a booster with the approved dosage, the US company announced in a press release on Monday.

The researchers had analyzed the antibody level in the laboratory 29 days after the booster vaccination.

You can read the preprint here.

A dose of 50 micrograms (millionths of a gram) is approved for booster for most people, which is only half as much as for the first and second vaccination.

With a booster vaccination of 100 micrograms, the neutralizing antibody level even increased 83-fold over the same period of time, writes Moderna.

The data, in which 20 people were examined per dose, have not yet been published in a specialist journal.

For immunodeficient people, 100 micrograms of the vaccine are approved for boosting.

There is still no data on how long the effects last after booster with the Moderna vaccine mRNA-1273.

The company is already working on the development of an Omikron-specific booster candidate.

In order to examine the effect of a vaccine against a virus variant, researchers usually do so-called neutralization tests. It is checked how many antibodies a vaccinated person has in the blood, which can bind to a - mostly artificially produced - virus variant and thus switch it off. The actual protection of vaccinated persons cannot be determined with this, however, clinical studies with thousands of test persons or evaluations of the ongoing infection process are required.

The vaccine manufacturers Biontech and Pfizer had previously announced that three doses of their product were necessary for adequate protection against the Omikron variant.

According to initial laboratory data, two doses did not provide sufficient protection against infection with this variant.

However, the companies assumed that protection against serious illness would continue to exist.

Last week, Moderna published a study according to which vaccinated people had significantly fewer neutralizing antibodies against Omikron than against certain earlier variants in their blood four weeks after the second dose.