Die Standing Committee on Vaccination STIKO currently recommends a second booster vaccination for all people over the age of sixty and all over the age of five who suffer from an underlying disease with an increased risk of a severe course of Covid-19 – preferably with a bivalent mRNA vaccine adapted to the omicron variant. The majority of people with a cancer diagnosis fall under the vulnerable group.
An active, i.e. current cancer is an independent risk factor for a severe course of Covid-19. There are two reasons for this. On the one hand, some tumor therapies weaken the immune system, so that infections are generally more difficult to cope with. On the other hand, the weakening of the immune system in cancer also means that vaccination against SARS-CoV-2 produces fewer antibodies. The vaccination is therefore usually less effective in the case of active cancer with a suppressed immune system than in healthy people without an immune deficiency. In cancer patients, the antibodies often disappear from the blood faster than in healthy people.
With the Omicron variant, the protection against symptomatic corona disease wears off more quickly than with earlier variants anyway, because omicron is an immune escape variant. Its mutations in the spike protein mean that the vaccine antibodies don’t match as well and are therefore less effective. Therefore, the vaccines were adapted to Omikron. The vaccination protects against a severe course. That is their primary goal.
Different levels of risk
The risk of a severe course is not the same for all tumor patients. Patients with haematological cancer, i.e. with various forms of blood cancer, have a significantly increased risk. Patients with lung cancer and patients with an advanced, solid tumor are also more at risk than other cancer patients. But here, too, there are individual differences, because every tumor is different and every patient brings their own personal risks and concomitant diseases.
The responsible working group on infections in the German Society for Hematology and Medical Oncology recommends in its new S1 guideline coronavirus infection in patients with oncological and haematological diseases expressly to be vaccinated (www.awmf.org/leitlinien/detail/ll/018-037.html).
The risk of a reduced immune response due to an immune deficiency is also not an exclusion criterion for vaccination. Rather, it indicates an “intensified” vaccination, as the guideline says. This means that high-risk cancer patients may need multiple booster shots. Marie von Lilienfeld-Toal from the University of Jena, who was significantly involved in the development of the guideline, does not make the decision to use further boosters dependent on the concentration of neutralizing antibodies in the blood, but on the time since the last corona vaccination and the individual situation and the individual risks of cancer patients.