The vaccine shortage in Germany makes it difficult to start the vaccination campaign against the coronavirus. So that as many people as possible can be vaccinated against Covid-19 as quickly as possible, the German Society for Immunology (DGfI) now points out that it is justifiable from their point of view to pursue a new vaccination strategy – in order to use the vaccination doses that are now available to enable many people to have their first basic immunization.
From day 14, the first vaccination already offers considerable protection against severe Covid 19 disease. In view of the high number of infections and deaths despite tough lockdown measures, it is acceptable to delay the second vaccination. However, the immunologists emphasize that it must follow within 60 days.
The European Medicines Agency and vaccine manufacturer Biontech are much more skeptical about the procedure. Because so far there is no data on whether the protective effect lasts longer than a few weeks after the first dose. Some believe that the body produces few protective antibodies after the first vaccination. “I believe that people are not well protected after the first injection,” says Sebastian Ulbert from the Fraunhofer Institute for Cell Therapy and Immunology.
There is agreement that a second vaccination is essential
For the full protective effect of the corona vaccines, the second injection is originally planned on day 21 (Biontech / Pfizer) or on day 28 (Moderna). This recommendation is based on clinical studies in which no other intervals were tested. The interval is based on experience with other vaccines and focuses on the fastest possible vaccination protection.
A shorter interval than 21 days between the first and second vaccination does not make sense, because otherwise the first immune reaction blocks the second. For some other vaccines, the immune response was even greater when a second vaccination occurred later than 21 days after the first. So far, however, it is unclear whether this could also be the case with mRNA-based vaccines.
However, there is agreement that a second vaccination is essential for a maximum and sustainable antibody response. The high efficiency of 94 percent for Moderna and 95 percent for Biontech / Pfizer was not documented for the two vaccines until seven days after the second vaccination.