This World AIDS Vaccine Day, Megan Wilson-Jones takes stock of the progress that has been made and some of the challenges facing researches in the development of an effective HIV vaccine.
May 18th marks the day to recognise and thank the HIV vaccine community for their continued work in developing a safe and effective HIV vaccine – arguably one of the greatest challenges in the history of vaccine research.
The development of a vaccine is a formidable task. Looking back over time, it took 105 years from the discovery of the typhoid bacteria to develop a vaccine for typhoid; 89 years for whooping cough; 47 years for polio and 18 years for hepatitis B. As scientific tools and technology have advanced greatly since the first vaccine was developed, researchers have gained a better understanding of the human immune system and how it functions. With this growing body of knowledge, researchers have reduced the time it takes from discovery of a pathogen to the development of effective vaccines to protect against major diseases.
Despite these advances, the development of an effective HIV vaccine has baffled scientists for nearly 30 years. It is the very nature of HIV which attacks the body’s own immune cells, which make designing a vaccine so challenging. Furthermore, HIV is a type of retrovirus – a group of viruses that integrate their genes into human genes and in doing so can completely ‘hide’ from an immune response. The way in which HIV is able to trick the body and escape the immune system makes it incredibly difficult to design and develop a vaccine which is meant to illicit and replicate natural immunity.
Although these are significant challenges, there have been impressive advances in understanding the virus and the associated immune response over the decades of research. Through the development and trialling of different types of vaccine candidates, the last few years have seen the most remarkable progress. In 2009, a clinical trial in Thailand found for the first time that a vaccine can prevent HIV infection, although the protection it provided was too low for it to progress to a fully licenced vaccine.
The International AIDS Vaccine Initiative (IAVI) is a global not-for-profit organisation which has been leading the way in the development of a safe and effective HIV vaccine. IAVI partners with organisations around the world, including academia, government research laboratories and pharmaceutical and biotech companies. With each sector having its own priorities and areas of speciality, IAVI works to bridge the gap between the innovation and development of novel technologies which often emerge from academic research, to more extensive vaccine research and development (R&D) and clinical trials, which are largely driven by pharmaceutical companies. By partnering with scientists in countries most affected by HIV, IAVI ensures that vaccine candidates are developed with the needs of these communities in mind. Currently IAVI’s portfolio includes 8 vaccine candidates across both pre-clinical and clinical stages.
The UK Government have been supportive of IAVI’s work, helping to address one of the greatest global public health needs of our time. With 1.6 million people dying of HIV every year and patients increasingly becoming resistant to early (first- and second-line) antiretroviral medicines used to treat HIV, there is an urgent need to develop an effective vaccine to free the world from HIV.