Fight against Delta variant: should the vaccination interval be shortened?

Anyone who has only received a primary vaccination is hardly protected against the delta variant of the coronavirus. However, because this mutant spreads quickly, shorter intervals between vaccinations are being discussed.

The delta variant of the corona virus is spreading rapidly in Germany and Europe. It is highly contagious and could jeopardize previous successes in the fight against the corona pandemic. In addition, researchers warn: Only a complete series of vaccinations seems to protect against the mutant – a first vaccination is not enough.

Against this background, a discussion has broken out about whether the intervals between vaccinations should be shortened in order to quickly increase the proportion of people with complete vaccination protection. This question is not trivial, said Thomas Mertens, head of the Standing Vaccination Commission (STIKO), the dpa news agency. There are various pros and cons arguments, according to the Ulm virologist. “We are currently trying to create the necessary evidence.”

Long intervals recommended so far

The STIKO has so far recommended longer intervals between the two vaccinations than would be possible according to the approval of the respective vaccines. There are several reasons for this: With AstraZeneca, for example, the effectiveness increases with longer distance. In addition, the shortage of vaccines spoke in favor of providing as many people as possible with the first vaccination.

At AstraZeneca, the previous advice from the panel of experts has been to allow twelve weeks to elapse between the first and second dose. For the BioNTech / Pfizer and Moderna mRNA vaccines, the recommended interval is six weeks. According to the approval, however, faster vaccination series would be possible: two BioNTech syringes every three weeks, with Moderna and AstraZeneca every four weeks.

Spahn against shortening the distances

Federal Minister of Health Jens Spahn pleaded for the second vaccination to be kept within the interval specified in the approval. “In the end, the doctor and the person to be vaccinated will decide within the interval,” said the CDU politician. It is foreseeable that well over 50 percent of the population will be fully vaccinated in four to six weeks.

The vaccination expert Leif Erik Sander from the Charité also said that in view of the low number of infections, one could “just carry on calmly”, as has been good and recommended so far. AstraZeneca, for example, does not want to risk a loss of effectiveness. The immunologist Carsten Watzl had previously made a similar statement on Twitter.

Braun wants first vaccinations for everyone

Chancellery Minister Helge Braun said in the ARD morning magazine When asked whether the intervals should be shortened in order to protect people from Delta more quickly: The challenge is first of all that everyone – with the exception of children under 12 – has a chance to have an initial vaccination. The second vaccination is less about the question of the convenience of the distance, but more about the effectiveness, according to the CDU politician. “We just know that a certain distance improves the effectiveness of the vaccination.” When asked whether a shortening was the advice of the hour, he answered in the negative.

“Shortening the current vaccination intervals, especially at BioNTech, of course makes sense in order to achieve a complete vaccination effect as quickly as possible,” explained the CEO of the National Association of Statutory Health Insurance Physicians, Andreas Gassen. “The maximum spread of the vaccination intervals at BioNTech is only justified by the lack of vaccines.”

Delta variant should soon dominate

The virologist Christian Drosten has been pointing out for a long time that the first vaccination against Delta does not help that much. The immunologist Carsten Watzl also recently told the dpa: “The second vaccination is urgently needed in order to be able to ward off the mutants well.”

In Germany, too, growing shares of the delta variant discovered in India are now being recorded. However, the number of cases caused by the mutant has only increased relatively slightly so far, while the trend for infections caused by the still dominant mutant Alpha is falling more sharply. In the future, it is expected that Delta will dominate the infection process here as well.