The booster campaign is rolling. The daily vaccination numbers are increasing again and should continue to increase. The bottleneck is the administration, there is enough vaccine available, at least in rich countries like Germany. Nevertheless, the development of vaccines continues, so-called protein vaccines are particularly urgently expected.
Novavax has now submitted its long-awaited application for approval to the European Medicines Agency. SanofiPasteur could soon follow suit. What are the benefits of the additional vaccines? An overview.
From genetically engineered coronavirus spike proteins. About a dozen are combined in a nanoparticle and act as a kind of artificial virus for the immune system. In order for this to work well, the vaccine also contains an enhancer, a chemical from the soap bark tree.
There are basically three advantages: Firstly, there has been long experience with protein vaccines, for example vaccinations against the flu, hepatitis B or whooping cough. Some people hesitate about the previous vaccinations because they are new and contain mRNA. Protein vaccines could therefore offer an alternative for people with reservations, especially since studies to date have shown them to be somewhat more tolerable.
They are also easier to use because they are easier to store – a normal refrigerator will do. This is why the Covax international vaccination campaign is also hoping for protein vaccines that would be easier to distribute globally. In addition, their production could also be taken over in the global south. Novavax has already promised Covax over a billion doses.
A study in England found the Novavax vaccine to be 83 percent effective. At that time, however, the alpha variant of SARS-CoV-2 was on the way. A parallel study in South Africa showed an effectiveness of only around 50 percent against the beta variant. In the middle of the year, Novavax also presented data from the USA and Mexico, where the effectiveness is said to have been over 90 percent. Nobody really knows how things will look with Delta.
The data from Novavax have convinced the responsible authorities in Indonesia, the vaccine has already received approval there. Novavax is not the only company that has developed a protein vaccine, and Sanofi Pasteur is already in active contact with the EMA. In some other countries mass vaccination campaigns are already running, for example in Cuba with its own protein vaccine. The number of infections there has been falling significantly since mid-September. It remains to be seen whether this is actually related to the vaccination campaign. Russia and China also use protein vaccines and have already passed them on to other countries. The problem: Most of the time, there are no fully published data on effectiveness and safety.
Protein vaccine technology is well established, but it must be adapted in any case. It is easy to send the instructions for the spike proteins in bioreactors full of insect or hamster cells or to integrate them into tobacco plants. But whether it works depends on the details. For example, if the cells produce the protein too quickly, they may die.
In addition, the protein still has to be purified and the process adapted to the individual case. In this respect, it was clear from the start that the protein vaccines would not be the first to be ready. How high the practical hurdles are was shown by the manufacturer Novavax, which repeatedly struggles with quality problems, even though it was supported by the USA with 1.6 billion dollars. And Sanofi Pasteur also had to completely rewrite the vaccine after unexpected problems with effectiveness.