Noch it is completely unclear how long the protection of a corona vaccination lasts. Because there is a lack of reliable data, even experts are currently having to guess. Six months, estimates the SPD health politician Karl Lauterbach. “The first refreshment will therefore be due in autumn for some,” Lauterbach recently told the newspapers of the Funke media group. Thomas Mertens, the chairman of the Standing Vaccination Commission (STIKO) at the Robert Koch Institute, assesses the situation somewhat more cautiously. You have to be prepared for the fact that “everyone may have to refresh their vaccination protection in the next year,” he said.
In general, the question of how long the vaccination protection against the coronavirus lasts can hardly be answered. After all, four vaccines are currently used in Germany, some of which differ significantly in their mode of action. But the duration of protection is not the only blind spot when it comes to the further progress of the vaccination campaign. This has just left its initial crisis phase behind it: The so-called prioritization has been lifted since the beginning of June, since then practically all those willing to vaccinate from the age of twelve in Germany can get protection against SARS-CoV-2 – even if it is here and there because of the lack of vaccine as it should take a while before the relevant dates can be arranged.
Double uncertainty could soon become a serious problem
The second problem for politicians and scientists is that there is currently no way of reliably determining individual vaccination protection. So it is currently not known how long the syringes will last, nor can it be determined in individual cases whether the protection is still effective. Experts fear that this double uncertainty could soon create a serious problem.
For good reason, those who were immunized at the beginning of the vaccination campaign were those for whom an infection with the coronavirus would probably have the worst consequences. In the first weeks of the campaign, it was mainly those in need of care who received the vaccination, as well as those over 80, carers and medical staff who were exposed to a particular risk of infection. The STIKO estimates the size of the first group to be at least nine million people. By the end of April it was possible to fully vaccinate the first six and a half million people in need of protection – that is, twice at an interval of a few weeks. If one proceeds from the conservative estimate, then your vaccination protection could already crumble by the end of October.
Manufacturers can’t agree on standards?
In order to check the vaccination protection, so-called antibody tests could be used. But in practice there is a problem. After all, manufacturers have now developed tests that are so good that they can tell whether someone has antibodies in their blood because of an infection they have suffered or whether they are antibodies that were formed after a vaccination. The antibodies that the immune system develops after the vaccination, so-called spike antibodies, differ from the other antibodies – the so-called nucleocapsids – that are formed after an infection.
However, it is still not clear how many antibodies are needed for the immune system to fight off an infection with the coronavirus. Laboratory physicians lack a scientifically based guide value for the so-called titer to be able to say with certainty that a patient is adequately protected against the virus. As early as the beginning of May, the Professional Association of German Laboratory Doctors (BDL) asked manufacturers to make “every possible effort” to determine generally recognized limit values. Not much has happened since then.
A dozen different tests for antibody determination are currently on the market, says Andreas Bobrowski, chairman of the BDL. One problem is that the results of the tests are hardly comparable – practically every test has its own limit values. If the manufacturers agreed on a standard, this process could presumably be accelerated. At the end of March, the World Health Organization (WHO) set a standard. Some test manufacturers already adhered to it, says Bobrowski. “I believe that in a certain amount of time we will be able to make standardized statements.” At the moment there is also “no clear picture” of how immunity changes over time after a vaccination. “It would be negligent to tell someone that we have measured a certain level of titre and that this will protect them for a longer period of time. We cannot make such a statement at the moment. “