Seasonal flu vaccaines are possible because the FDA has well established procedures for giving fast-track approval for this particular catagory of drugs. Normal

Seasonal flu vaccaines are possible because the FDA has well established procedures for giving fast-track approval for this particular catagory of drugs. Normall it takes many years to gain approval for a new drug, or even an iteration of an existing drug. In addition, new HIV strains do not arrive in predictable yearly 'waves' like influenza does, new strains arise randomly within the infected population.