What’s on the horizon for cancer vaccines?

The essence of a vaccine is recognition. The body learns to recognize a threat and mounts a targeted immune response. For more than 200 years, vaccines have helped prevent deadly diseases caused by viruses and bacteria, according to research published by the Cancer Research Institute (CRI).^[]

With microbes, the antigen presented is clear. This, however, is not the case with cancer cells, which present similarly to their healthy counterparts. The development of cancer vaccines is therefore challenging, and sophisticated strategies are required.

Types of cancer vaccines

Several viruses cause cancer. Preventive cancer vaccines include those developed to fight HBV (ie, liver cancer) and HPV (ie, cervical cancer), according to the CRI research.

Examples include Cervarix, Gardasil, and Gardasil-9, which protect against different strains of HPV, and the HBV vaccine, which protects against HBV infection and associated liver cancer.

Neoantigen vaccines are developed based on mutations in cancer cells that are called neoantigens. The upside of neoantigen vaccines is that the immune response can attack cancer cells only and spare healthy cells, which don’t express mutations.

More about neoantigen vaccines

“Since neoantigens can be shared by a number of cancer types that are not usually lost due to immune escape, they may be a promising choice to be used as cancer vaccine targets in immunotherapeutic approaches,” wrote the authors of a review published in Cancers.^[]

Examples of neoantigen vaccines in development include those against the target Mucin 1 (MUC1); MUC1 is overexpressed in various adenocarcinomas.

Another target is the human epidermal growth factor receptor 1 (HER2/neu) in which anti-HER2/neu antibodies block cancer progression.

Looking forward

Several anticancer vaccine strategies have been proposed.

One approach involves leveraging small interfering RNAs and short-hairpin RNAs versus immunosuppressive factors in dendritic cells. Dendritic cells are polarized into immune suppression. This polarization impacts T cell activation and bolsters the differentiation of regulatory T cells, which mediate tumor growth.

In animal models, combining adipose-derived stem cells and the E7 cancer antigen specific protein decreased the endothelial cell marker CD31 and the vascular endothelial growth factor, and boosted CD4+ T cells, CD8+ T cells, and natural killer cells. These results point to a possible immunotherapy approach, according to the Cancers article.

mRNA vaccines for cancer

The key to the successful development of an mRNA vaccine is to produce it quickly, within weeks of the tumor biopsy. Intriguingly, research on mRNA vaccines for cancer laid the groundwork for the swift development of a COVID vaccine using the same technology, according to an article published by the National Cancer Insitute.^[]

Thanks to the success of mRNA vaccines in battling COVID-19, substantial research money is being directed toward the discovery of new mRNA vaccines. Dozens of clinical trials testing mRNA cancer treatments are underway, including studies for colorectal cancer, pancreatic cancer, and melanoma.