Question 1

What is the difference between preventive and active cancer vaccines?

Accepted Answer

Preventive cancer vaccines protect healthy individuals against cancer-causing viruses before infection occurs, such as the human papillomavirus vaccine for cervical cancer. Active cancer vaccines treat existing cancers by stimulating the immune system to recognize and attack tumor cells. Both types leverage the body's adaptive immunity but differ in timing and target.

Question 2

How do whole-cell cancer vaccines like GVAX work?

Accepted Answer

Whole-cell vaccines such as GVAX use genetically modified or irradiated cancer cells that produce cytokines like GM-CSF to stimulate anti-tumor immune responses. These modified cells trigger the immune system to recognize and attack similar cancer cells in the patient's body, providing a broad-based treatment approach.

Question 3

What role do dendritic cells play in cancer vaccine treatment?

Accepted Answer

Dendritic cell vaccines, like Provenge, isolate a patient's dendritic cells, which are antigen-presenting cells. These cells are exposed to cancer-specific antigens such as prostate-specific antigen, then reintroduced intravenously into the patient to trigger a targeted immune response against tumor cells.

Question 4

How do tumor antigen vaccines target specific cancer cells?

Accepted Answer

Tumor antigen vaccines like PROSTVAC use recombinant poxviruses to deliver cancer-specific antigens, such as prostate-specific antigen, to host cells. This approach enables the immune system to recognize and target cancer cells expressing those specific antigens, providing precision in cancer treatment.

Question 5

Why might combining cancer vaccines with checkpoint inhibitors be effective?

Accepted Answer

Cancer cells often suppress immune responses through checkpoint mechanisms. Combining cancer treatment vaccines with checkpoint inhibitors helps overcome this immune suppression, allowing the vaccine-stimulated immune system to more effectively recognize and attack tumor cells. Early research suggests this combination enhances therapeutic effectiveness.

Question 6

What makes personalized cancer vaccines a promising treatment approach?

Accepted Answer

Personalized cancer vaccines tailor treatment to individual patients' specific tumor profiles and genetic characteristics. This customized approach allows vaccines to target the unique antigens present in each patient's cancer, potentially improving immune recognition and attack of tumor cells compared to standardized vaccines.

Question 7

How does the HPV vaccine prevent cervical cancer?

Accepted Answer

The human papillomavirus vaccine protects against common viral strains that cause cervical cancer by stimulating the immune system to respond against specific HPV types before infection occurs. As a preventive vaccine administered to healthy individuals, it establishes immunity against oncogenic viral agents.

חיסונים נגד סרטן