Table 1. Questions for further thought.

There are still numerous outstanding questions to be addressed to better understand the similarities and differences between immune responses to infections and tumors.

Questions for further thought

• What innate immune pathways are important for immune recognition of tumors?

• In what respects is the immune response to a tumor similar to the immune response to a chronic infection?

• Why are therapeutic vaccines rarely used to treat infections? Given this, why is it believed that they may be useful in treating cancer?

• Can prophylactic vaccines be developed for cancer?

• Could passive monoclonal or bispecific antibody therapies used to treat cancer also be applied to infections?

• Can checkpoint blockade provide an effective therapeutic strategy for infections?

• How can cytotoxic T cell responses best be elicited in a vaccine? Would such vaccines be of benefit for immunization against tumors and intracellular pathogens for which we currently lack effective vaccines?