Combining Prime and Boost May Provide Effective Immunization Against Cancer

In her laboratory at the University of Montreal Hospital Research Centre (CRCHUM), Marie-Claude Bourgeois-Daigneault and a team of scientists modify viruses to make them specific to the cells of a tumor.

Once in the patient’s body, these oncolytic viruses infect and destroy the cancer cells without touching healthy cells. The viruses can even stimulate the immune system to be better armed to recognize and kill malignant cells; this is immunotherapy.

In a study published in Nature Communications on May 11, 2021, Daigneault and her team show how they came to create an effective personalized vaccine by combining oncolytic viruses with small synthetic molecules (peptides) specific to targeted cancer.

By conferring systemic protection and durable benefits, cancer immunotherapies are emerging as long-term solutions for cancer treatment. 

One such approach currently undergoing clinical testing is a therapeutic anti-cancer vaccine that uses two different viruses expressing the same tumor antigen to prime and boost anti-tumor immunity. 

Providing the additional advantage of directly killing cancer cells, oncolytic viruses (OVs) constitute ideal platforms for such treatment strategy. 

However, given that the targeted tumor antigen is encoded into the viral genomes, its production requires robust infection. Therefore, the vaccination efficiency partially depends on the unpredictable and highly variable intrinsic sensitivity of each tumor to OV infection. 

In this study, the researchers demonstrate that anti-cancer vaccination using OVs (Adenovirus, Maraba virus, Vesicular stomatitis virus, and Vaccinia virus) co-administered with antigenic peptides is as efficient as antigen-engineered OVs and does not depend on viral replication. 

This strategy is particularly attractive for personalized anti-cancer vaccines targeting patient-specific mutations.

These researchers suggest that the use of OVs as adjuvant platforms for therapeutic anti-cancer vaccination warrants testing for cancer treatment.

Vax-Before-Cancer publishes research-based vaccine news.