On Monday, May 17, staff from the History of Vaccines project traveled to Washington, D.C. to attend “New Promise in the Search for HIV, TB and Malaria Vaccines,” a joint briefing held on the 30th anniversary of the eradication of smallpox.
In their opening remarks, Dr. Alan Bernstein (Global HIV Vaccine Enterprise), Dr. R. Gordon Douglas, Jr. (Aeras Global TB Vaccine Foundation) and Colonel Chris Ockenhouse (U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research) all stressed the need for continued efforts toward vaccines for malaria, HIV, and TB. They also highlighted the overlap between the incidence of the three diseases, as well as the interaction between them: Douglas specifically stressed the importance of developing a TB vaccine that can be used in HIV-positive individuals.
We at the History of Vaccines project were happy to provide material for the keynote talk by Dr. Gregory Poland (Vaccine Research Group, Mayo Clinic). Dr. Poland discussed historical and contemporary challenges in vaccine development and deployment, including political agendas and the threat of diseases as bioweapons post-eradication.
Dr. Dan Barouch (Division of Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School) discussed the search for an HIV vaccine. He compared potential HIV vaccines to the vaccine for smallpox, noting that while the smallpox vaccine offered broad immunity using attenuated viruses against a disease with limited viral diversity, HIV rapidly mutates and has extensive worldwide diversity. In addition, he noted, attenuated HIV viruses are unsafe for human use, and there is little pharmaceutical interest in the development of an HIV vaccine.
Dr. Barouch expressed dissatisfaction with the progress toward a vaccine over recent decades (only three concepts tested in clinical efficacy trials in 25 years) but highlighted the positive results of the RV144 prime-boost “Thai trial.” Initial data from the trial showed that vaccine recipients were about 30% less likely to become infected with HIV than those who had received a placebo. While this is only a modest demonstration of efficacy and data from the trial is still being analyzed, Dr. Barouch cited the RV144 results as an opportunity to investigate the scientific basis of protection against HIV.
Dr. Hoosen Coovadia (University of KwaZulu-Natal, Durban, South Africa) discussed the scale of the worldwide TB problem–9.4 million new diagnoses each year, and one in three individuals infected. Drug-resistant TB has been identified in every region of the world, and the existing BCG vaccine does not protect against pulmonary TB. It also can’t be used in HIV-infected children.
Dr. Coovadia noted that Aeras has a goal of a more effective, safe, and affordable TB vaccine by 2016. The organization has two viral vector vaccines that have completed Phase IIb trials, and a new vaccine candidate is expected to enter clinical trials this year.
Dr. Ashley Birkett (PATH Malaria Vaccine Initiative) noted that 40% of the world population is at risk for malaria, citing 250 million clinical cases and one million annual deaths. Dr. Birkett highlighted numerous problems in current treatment methods, including developing resistance to drugs among the parasites and developing resistance to insecticides among mosquitoes. He also noted additional challenges, both scientific and commercial, specific to the development of a malaria vaccine: there is no vaccine in human use against a parasite; the parasite has more than 6,000 genes (many more than a virus); and there is a limited market in developed countries (malaria-endemic countries are mostly poor).
Dr. Birkett included a discussion of the RTS,S subunit vaccine, which was demonstrated to be 50% effective in three doses in a clinical trial.
Concluding the briefing, Dr. James Kublin (HIV Vaccine Trials Network) once again noted the wide geographic overlap between HIV, malaria, and TB, citing HIV as the most powerful factor to increase the risk of TB infection. He highlighted the soaring costs associated with HIV infection: $355,200 per U.S. case. With 56,000 infections per year in the U.S., the total cost approaches $20 billion.
Dr. Kublin discussed adaptive clinical trial techniques as a method of speeding the evaluation of vaccine candidates, noting that the FDA is reviewing guidelines for adaptive clinical trial designs. He added that there is a goal to initiate at least three adaptive trials of HIV vaccines by 2015.
Watch the History of Vaccines blog for announcements about future events related to vaccine development for these diseases.
The event was sponsored by Aeras Global TB Vaccine Foundation, the Global Health Council, the Global HIV Vaccine Enterprise, the HIV Vaccine Trials Network, the International AIDS Vaccine Initiative, the Jenner Society, the PATH Malaria Vaccine Initiative, the U.S. Military HIV Research Program, the U.S. Military Malaria Vaccine Research Program, the Vaccine Research Group, Mayo Clinic, and the It’s Time Campaign. The It’s Time Campaign is scheduled for an official launch this Fall as a foundation focused on advancing HIV, TB and malaria research, and advocating for the licensure of partially-effective vaccines.
This post was updated on Wednesday, May 26, to provide additional information about the It’s Time Campaign.