Cancer in the Pandemic: Vaccination Recommendations for the Vulnerable

The Standing Vaccination Committee 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. Vaccine.

The majority of people with a cancer diagnosis fall under the vulnerable group.

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 Omikron variant, the protection against symptomatic corona disease wears off more quickly than with earlier variants anyway, because Omikron 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.

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 expressly recommends in its new S1 guideline on coronavirus infection in patients with oncological and hematological diseases 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,

Antibody titers say nothing about actual protection

According to the infection researcher, checking the antibody titer using a serological test says nothing about the actual protection against a severe course, because it is not known what value stands for reliable protection.

"No matter what comes out of the serological test, the result can neither reassure nor worry.

It doesn't help with the clinical decision," she says.

Therefore, the distance to the last vaccination is decisive for them, not the amount of antibodies against SARS-CoV-2.

In its recommendations, the STIKO also speaks out against a general antibody test to check the success of the vaccination.

Is there an ideal time for the corona vaccinations for cancer patients?

For the overwhelming majority of patients, the time is surprisingly irrelevant, says von Lilienfeld-Toal.

If possible, the vaccination should be given before the start of chemotherapy, so that there is enough time for a good immune response.

If that's impossible, it still doesn't make sense to postpone the therapy significantly.

As for the side effects of vaccination, having cancer does not increase the risk.

"According to everything that we know today from prospective studies, and that is now a great deal, there is no evidence of an increased rate of side effects or a different spectrum of side effects in cancer patients," says von Lilienfeld-Toal.

According to her, there are also no recommendations for or against a specific corona vaccine for cancer.

A few weeks ago, the scientist and her colleagues published an overview of corona vaccination in cancer patients in the journal "Nature Reviews Clinical Oncology".

How do the new immunotherapies against cancer affect the immune protection provided by vaccination?

Checkpoint inhibition unleashes the immune system by releasing a brake.

Therefore, two opposite scenarios are possible.

Checkpoint inhibition reduces or even enhances the vaccine response because it activates the immune system.

"My experience is that checkpoint inhibition in the corona vaccination is neither harmful nor useful," says von Lilienfeld-Toal.

"But there are different opinions about it." The treatment is complex, the patients often have many different risk factors.

It is therefore difficult to decide what plays a causal role in the vaccination effect and what does not.

The last word has not yet been spoken on the checkpoint inhibitors.

For cancer patients, protection against infection with SARS-CoV-2 and other infections remains extremely important.

The doctor therefore expressly recommends cancer patients to be vaccinated against influenza.

Everything that supports optimal treatment of the cancer is important, she says.

This includes the flu vaccination.