Covid-19 vaccination: a cure for cancer?

By Lisa Westra

The treatment of patients with cancer could become significantly more successful when it includes vaccination against covid-19, a groundbreaking new study says. 

A recently published study among almost 900 participants in the scientific journal Nature reports that vaccination against covid-19 could make tumors sensitive to immunotherapy. Researchers from the University of Texas found that the chances of survival of patients with two specific types of lung or skin cancer was significantly improved, if they got the vaccine within 100 days after the start of treatment. While about 30% of the patients that were not vaccinated was still alive after three years, the vaccine increased this percentage to over 55%. 

Normally, tumors can defend themselves against the immune system. They do this by producing specific ‘messengers’ which trick the immune system into thinking the tumor is not a threat. Immunotherapy is meant to block these messengers. This way, the immune system can recognize the tumor as dangerous and attack it. 

However, sometimes the tumor is so good at tricking the immune system that immunotherapy does not work. This makes the tumor resistant to the treatment and explains why many patients do not respond to immunotherapy. 

The recently published study suggests that this can be changed when the patients are vaccinated against covid-19. The researchers found that specifically mRNA vaccines can improve the effectiveness of immunotherapy. The vaccine enables the immune system to better distinguish the tumor cells from healthy cells. It also activates a specific type of immune cells, T cells, which are very good at killing tumor cells. 

Counterintuitively, the mRNA vaccine also increased the production of one specific messenger that tricks the immune system. This would mean that the T cells are prevented from attacking the tumor. This is where the effective combination of the vaccine with immunotherapy takes place: when the specific messenger was blocked by the immunotherapy, the activated T cells became more efficient at killing the tumor.

In short, the vaccine boosts the immune system, which means it is more active in attacking the tumor. Although the tumor will try to defend itself, the immunotherapy will block this defense. The activated T cells can then still recognize the tumor as a threat. These effects are so strong that they can make a tumor sensitive to immunotherapy, even if it was resistant before.

Although the promising effects of covid-19 vaccination to boost immunotherapy have only been shown for two types of cancer, the vaccine may be effective for way more tumors. This type of vaccine is widely available and therefore easy to add to immunotherapy, according to the researchers. This revolutionary study may therefore have marked the beginning of a new era in cancer treatment.