There is nothing I would like better than to wake up and learn of a new and effective HIV vaccine (except maybe a malaria vaccine), so I was excited to hear of a successful vaccine trial this morning. Multiple news agencies reported that a vaccine reduced the risk of HIV infection by 30%.
While the media loves a big story, these results were underwhelming. Although they were "statistically significant," it is way too early to declare success. A simple look at the numbers is more sobering: after vaccinating 16,000 people, there were 23 fewer new infections in patients receiving the vaccine (51 cases versus 74 cases). If one additional patient who received the vaccine became infected (52 instead of 51) the results would no longer be "statistically significant."
A misunderstanding of statistics and study design often leads to premature optimism as well as fear, when new studies come out. Today we learned that combining multiple injections of two vaccines that proved unsuccessful in the past may reduce the chance of new infections. I remain hopeful but VERY skeptical, given the modest differences and lack of biological evidence (there was no difference in viral loads between vaccinated and non-vaccinated patients who acquired HIV). While I am encouraged by the efforts and work being done to develop a vaccine, we have yet to find a silver bullet.
Meanwhile, condoms, education and empowering women remain the most effective ways to reduce infection. Improving access to treatment and to providing prophylactic medicines for pregnant HIV infected women are also incredibly successful and cost effective.
We currently spend a lot of money on abstinence education programs, which have proven unsuccessful and often highlight the failures of condoms. Encouraging abstinence and faithfulness are noble goals, but they should not divert money from strategies with a stronger track record of success. While we continue to wait for more promising results of vaccine trials, we should not wait to deliver more condoms, sex education, clean needles and drugs to reduce perinatal transmission of HIV.