Transcript of video
You already mentioned that the coronavirus antibody titers might decrease with time. So that’s why cellular immunity against coronavirus is very important. And by now, the data accumulates in people who recovered from covid 19 coronavirus infection. Their antibody titers decrease with time. Does that mean that their immunity potentially becomes less and less? Or, as long as they have some antibodies, immunity against coronavirus could be effective. What is known to date about it? It’s a continuously changing situation. My group had a paper accepted in Immunity, one of the major journals in the immunological field. We demonstrated that in about 50% of the patients after COVID-19, the antibody levels disappeared after three months. However, this does not mean that you are not immune to the coronavirus. Because in the later phase, the T cell response drives the immunogenicity and not the antibody level. We do not know this for the SARS-CoV-2 virus in detail. But, for example, we know it for other viral infections. And I will give you an example of Hepatitis B. After hepatitis B vaccination, the T cell memory is no more measurable, normally, after five years. But there is still protection for the next five years against Hepatitis B. So a good T cell response means long-term immunity and this independent of the antibody response. So people could have some hope that even if their antibody titer is diminishing, nevertheless, there might be a residual cellular T cell immunity. It could protect them at least from the severe COVID-19 infection. I think that segues into an important question that many people are asking. If somebody had a COVID-19 infection, clinical coronavirus disease, does it make sense for them to be vaccinated? If and when coronavirus vaccine becomes available to them. Do you think it’s safe for people who had clinical coronavirus infection to be vaccinated with one of the approved COVID-19 vaccines? Again, this is a Nobel Prize question. So what we did in Germany we did not recommend the coronavirus vaccine to people who had confirmed COVID-19 disease in the beginning. But it couldn’t be clever to be immunized later on. Because then the immunogenicity may come down. So whether it’s safe to be immunized after a COIVD-19 infection, that’s difficult to answer a question. There could be an overreaction by a second contact with the virus. But this has not been shown yet in any way. And I’m sure there are many patients, which suffered from COVID-19, but the disease had never been confirmed, and they will be vaccinated. Of course, a COVID-19 antibody measurement is not a baseline condition for giving the coronavirus vaccine. So we will get data about these hyper-inflammatory response at second contact [with coronavirus antigens]. I’m not so threatened. I think maybe in very rare cases, [over-reaction to vaccine] could occur, but it’s not the main finding.