which-of-the-following-best-describes-why-a-vaccine-against-hiv-has-not-been-dev

Question

Which of the following best describes why a vaccine against HIV has not been developed?

Accepted Answer

Mutation rate of HIV is extremely high.

Answer

The cost of developing an HIV vaccine is extremely high.

Answer

Several drugs are available to combat it, so no vaccine is required.

Answer

The human immune system is capable of fighting the virus.