Many people are unsure: Should they resort to the already approved vaccine against the omicron variant BA.1? Or is it better to wait for the expected vaccine against BA.4/BA.5? Immunologist Watzl advises risk patients not to hesitate too long.
After the approval of another omicron booster in the EU, the immunologist Carsten Watzl advises risk groups not to wait for its availability in Germany. "Anyone who falls under the previous recommendation of the Standing Vaccination Commission for a second booster vaccination should now take the vaccine adapted to the omicron subline BA.1, which is arriving at general practitioners these days," said the Secretary General of the German Society for Immunology. These people, such as those over 60 and/or people with certain previous illnesses, should not wait weeks for the somewhat newer preparation because of several unanswered questions.
On Monday, a committee of experts from the EU medicines agency EMA issued a recommendation for the approval of a booster from Biontech/Pfizer, which is adapted to the currently circulating sub-lines BA.4/BA.5. The European Commission then immediately granted approval. At the beginning of September, vaccines adapted to variant BA.1 were approved. But BA.1 hasn't played a role in Germany for a long time. Both the vaccines adapted to BA.1 and those adapted to BA.4/BA.5 also take into account the original Sars-CoV-2. The goal is broader protection.
There is no data on the frequently asked question of which of the two new vaccines is better, said Watzl. In experiments with animals, the respective results were similar, but there were no direct comparisons. "In this respect, it is open to me how much advantage the vaccine adapted to BA.4./BA.5 really brings." The effectiveness also depends on which corona variants will circulate in the next few months - but it is currently unclear in which direction the virus will develop. For younger, immune-healthy people and people who went through a corona infection in the summer, experts currently see no need for an omicron booster. "It would be surprising if BA.4/BA.5 were to keep us busy in autumn and winter. New variants will come at some point," said the Dortmund immunologist. In the two omicron sublines that are currently under international observation - BA.2.75 and BA.4.6 - he does not see the potential for spreading in this country.
For a better fit of the vaccine in view of the current variants, two data sets in particular were used for approval, as Watzl described: data from studies on people with the BA.1 vaccine and results of the BA.4/BA.5 vaccine from trials with mice for immune response. The fact that there is only data from mice, but not from humans, especially for the latest vaccine, should not be overestimated, said Watzl. "This is not a huge human experiment, nor is it an experimental vaccine." The BA.4/BA.5 vaccine is minimally changed compared to the BA.1 vaccine and ultimately also to the original preparation. In addition, very rare side effects cannot be recorded even in clinical studies with several hundred subjects, said Watzl. "However, new, antigen-specific side effects are not to be expected in this case. Otherwise, they would also have to occur in infections with the virus."
Watzl reiterated his desire for an early STIKO recommendation on the adapted vaccines. "People want to know what to do." He hopes the panel will not wait for application data from the US (BA.4/BA.5) and UK (BA.1).
