COVID vaccination also advisable for people with cancer
15.03.2022 12:49
A vaccination protects people with cancer well against COVID disease - even if it is caused by virus variants. This is the conclusion reached by an international team led by hematologist Marie von Lilienfeld-Toal. The researchers systematically re-evaluated dozens of studies. In particular, the multiple vaccinations intended to provide effective protection against COVID help people with cancer. The results of the literature search were published in "Nature Reviews Clinical Oncology".
An infection with the SARS-CoV-2 coronavirus is particularly dangerous for people with cancer. “The mortality rate in this group is around twenty percent,” says Marie von Lilienfeld-Toal. The internist and hematologist is a professor at the Department of Internal Medicine II at Jena University Hospital, and her “Infections in Hematology/Oncology” working group conducts research at the Leibniz Institute for Natural Product Research and Infection Biology in Jena. As deputy chairwoman of the Infections in Hematology and Oncology Working Group of the German Society for Hematology and Oncology (DGHO), she has been involved in the development of numerous guidelines for the treatment of COVID in cancer patients since the beginning of the pandemic.
“We also gave recommendations on COVID vaccinations for cancer patients at the beginning of 2021,” said von Lilienfeld-Toal. Now she and an international research team have re-evaluated more than 60 studies on the immune response in cancer in order to be able to provide a comprehensive analysis of the effectiveness and possible risks of vaccination in this patient group.
Their conclusion: “It can be assumed that the vaccination actually works on cancer patients.” This group of people does not take part in the approval studies, which is why the effectiveness and risks can only be evaluated afterwards. “Our evaluation has shown that the effectiveness of the vaccinations is around 80 percent. “This is very good compared to the flu vaccination, where the effectiveness is generally significantly lower,” said the doctor. The mRNA vaccines are the most effective. The evaluation also includes effectiveness against the new omicron variant of SARS-CoV-2.
In addition, the multiple vaccinations that are already provided for the corona vaccines are helpful for cancer patients. “We have observed in many studies that multiple vaccinations against other viral infections work better than single vaccinations when it comes to cancer,” says von Lilienfeld-Toal. The immune system often does not kick in during the first vaccination.
The problem with cancer is that the weakened immune system both promotes serious illnesses and reacts more poorly to vaccination. “Our observation is that a single vaccination can be strongly influenced by cancer therapy. This effect can be leveled out by multiple vaccinations - then it doesn't matter at what point in the therapy the vaccination takes place," explains the internist. However, the success of the vaccination also depends heavily on the type of cancer treatment. A therapy that specifically attacks the immune system - for example in the case of blood cancer - leads to a significantly reduced immune response.
The evaluation also showed that the antibody titer is not a good indicator of effectiveness. “Approximately half of the new studies we evaluated also measured the immune response of T cells, a group of immune cells that also specifically recognize antigens,” explains von Lilienfeld-Toal. This procedure is not very standardized and is not used routinely. However, it shows that even if antibodies are not formed, specialized T cells are often developed against SARS-CoV-2.
With regard to possible risks, it can be said that a vaccination definitely has fewer side effects than a COVID illness. The risks are comparable to corresponding groups of the average population; a negative effect on cancer was not observed in any of the studies. Only the reaction to radiation therapy was increased in some cases. In addition, possible swelling of the lymph nodes after the vaccination sometimes led to the false assumption that new foci of cancer had arisen. This should be taken into account in the diagnosis.
The systematic research of numerous study results was carried out by an international team of authors, each of whom also conducts their own research on COVID in cancer. Marie von Lilienfeld-Toal is funded by the German Research Foundation as part of the Collaborative Research Center/Transregio 124 FungiNet and by the German Cancer Aid as part of the OncoReVir project.
Source:
Fendler A, de Vries EGE, GeurtsvanKessel CH, Haanen JB, Wörmann B, Turajlic S, von Lilienfeld-Toal M (2022). COVID-19 vaccines in patients with cancer: immunogenicity, efficacy and safety. Nature Reviews Clinical Oncology, https://doi.org/10.1038/s41571-022-00610-8