Vaccines are essential in campaigns against HIV and TB, say researchersBMJ 2012; 344 doi: https://doi.org/10.1136/bmj.e3625 (Published 22 May 2012) Cite this as: BMJ 2012;344:e3625
Major breakthroughs in the development of vaccines against HIV and tuberculosis over the past decade have resulted in a number of promising candidates entering late stage clinical trials. Yet participants at a symposium held last week by the UK Consortium on AIDS and International Development warned that this progress could be jeopardised by the recent downturn in global health funding.
The meeting heard that currently 71 HIV vaccine trials and 15 trials of tuberculosis vaccines are ongoing.
Robin Shattock, of Imperial College London, said that one HIV vaccine candidate, RV144, had recently completed stage III trials in Thailand, showing a protective efficacy of over 30%.1 Although this figure was not yet ideal it showed “light at the end of the tunnel” by demonstrating proof of concept.
Shattock pointed out that the global prevalence of HIV has remained constant at 0.8% of the population since 2001. Although 6.6 million people are currently taking antiretrovirals, nine million are waiting to receive treatment, and “for every person starting ART [antiretroviral therapy] two people are newly affected.”
Hester Kuipers, of the International Aids Vaccine Initiative, said that even if all other techniques to reduce the spread of HIV were fully funded, a successful vaccine would still be extremely cost effective. Current trends indicate that a future vaccine could save between $46bn and $95bn in averted treatment costs during the first 10 years of its introduction.
Richard White, of the London School of Hygiene and Tropical Medicine, said that new tools were urgently needed if tuberculosis was ever going to be eliminated as a public health problem. Despite recent efforts, prevalence of the disease was falling by only 1% a year, and even this progress was threatened by the emergence of drug resistance and coinfection with HIV.
Adam Stoten, of the Oxford Emergent Tuberculosis Consortium, said that the existing BCG vaccine was very widely used, with over 100 million doses a year. But he added that it had only “variable efficacy” against pulmonary disease, cannot be given to people who are HIV positive, and suffered from a “latitude effect” of unknown cause, which meant that it was less effective near the equator.
Great progress had been made in finding a replacement over the past 10 years, and several promising candidates are in the pipeline. But Stoten warned that late stage trials were expensive and that “we cannot afford to lose momentum.”
Although prevalence of tuberculosis is high, “low disease incidence rates dictate that efficacy trials must recruit large numbers of people with long periods of follow up,” he said. Any successful vaccine will be required in large quantities, meaning that “affordability will be a key issue” and that “continued public funding support is vital.”
Aaron Oxley, of the health advocacy group Results UK, said, “We’ve been making real progress and are confident that we’ll soon have effective vaccines that will really transform the fight against these killer diseases.
“The evidence is clear: through vaccines we’ve been able to eradicate smallpox, are on the brink of eradicating polio, and have massively driven down measles deaths in just a few years. If we’re serious about ending AIDS and TB, we’re going to need new vaccines; and if we don’t continue to fund the current pipeline hundreds of millions of dollars of previous investment—and millions of lives—will be lost.”
Cite this as: BMJ 2012;344:e3625
See the Results UK blog at http://bit.ly/JtlAbo.