Can cancer vaccines help prevent disease?

Cancer vaccines are not like vaccines for the flu or other infectious diseases. Cancers are not contagious to humans, but are caused by problems in the body, usually when the immune system is weakened. So cancer vaccines are not necessarily drugs that will prevent you from getting cancer, but are primarily considered treatments for cases that have already been diagnosed.

Some preventive vaccines that can protect against cancer before you get sick include vaccines that protect against viruses that increase your risk of cancer (hepatitis, HPV).

Recent progress in cancer vaccine research has been fueled by the development of mRNA vaccines against COVID-19.

mRNA technology is popular in the field of oncology and many countries are also in the process of researching cancer vaccines based on this technology.

mRNA vaccines work by encoding the protein chain of cancer antigens in mRNA, introducing this mRNA into the body so that these antigens are produced in the body and forcing the immune system to attack them.

So mRNA vaccines would be personalized based on each person’s “tumor passport.” Analyzing the genetic makeup of a patient’s cancer cells would reveal exactly how to tweak the vaccine so that the patient’s immune system starts fighting it.

Scientists are still at the beginning of their journey to creating a full-fledged cancer vaccine. There are many problems to solve and a long way to go before theory becomes reality.

First of all, not all tumor cells have their own antigens, which is a key requirement for developing a vaccine. If you target the immune system to antigens that are also present in healthy cells, the vaccine will destroy them as well, and the consequences of this can be very dangerous.

Furthermore, tumor cells do not always “obediently” await the fate that vaccines have created. They can use various mechanisms to become invisible to the immune system, or evolve, trying to survive the attack of the immune system. In some cases, vaccines only prolong life but do not cure the disease.

In the fight against cancer, the size of the tumor also plays a big role. Even if there is a necessary immune response, it may not be enough to completely overcome the tumor. The immune system itself can also weaken the body.

Even if a vaccine is found to be effective for a particular cancer, it will still need to be tailored to different groups of people: the elderly, children, people with comorbidities.

Developing an mRNA vaccine also involves creating a personalized medicine, meaning each patient would need to have their own injection based on tumor analysis.

Producing such a vaccine is not only time-consuming (and during this time the tumor has time to change), but also expensive.