Modification of the tumor microenvironment was not seen in mice that received the vaccine via needle injection into the skin.
Researchers from the National Institute of Allergy and Infectious Diseases (NIAID), a division of the National Institutes of Health, report that an experimental therapeutic cancer vaccine induced two distinct and advantageous immune system responses that resulted in a significant tumour regression in mice.
The delivery of the vaccine intravenously (IV) increased the amount of cytotoxic T cells capable of penetrating and destroying tumour cells and activated the innate immune system by producing type I interferon, according to the researchers.
The innate immune response altered the tumour microenvironment by combating inhibitory factors that would have otherwise stifled T-cell activity. In mice that got the immunisation by needle injection into the skin, the tumour microenvironment did not change (subcutaneous administration).
The scientific team’s method, known as “vax-innate,” accomplishes a crucial objective in the search for more potent immunotherapeutic cancer vaccines. The study shows that tumor-induced immunosuppressive activity is overcome by IV vaccine administration, enabling and enhancing T-cell immunity.
The proposed vaccination, according to the researchers, may also be administered intravenously to patients who have already received tumor-specific T cells as a kind of therapy. According to the researchers, it may also enhance tumour control by boosting T cell numbers and improving the tumour microenvironment.
Robert Seder, M.D., and colleagues at the NIAID Vaccine Research Center (VRC), along with partners from Vaccitech North America, a clinical-stage biopharmaceutical business in Baltimore, Maryland, developed the experimental vaccine known as SNAPvax.
In 2023, Vaccitech hopes to develop the SNAPvax platform for use in treating cancers linked to the HPV.
Parvathy Sukumaran 
