New hope for HIV/AIDS patients as a groundbreaking vaccine goes under trial in South Africa. The HTVN-702 trial will compare new infection rates in 5400 patients up to 36 months after vaccination. If successful, the researchers hope that the vaccine form part of a cohesive effort to reduce new infection alongside established ‘safe sex’ and screening. HIV/AIDS remains a global epidemic, killing over 1.1 million yearly from associated infections.
The trial, which will conclude in 2020, will compare those vaccinated with a combination of agents ALVAC-HIV and Bivalent Subtype C gp120/MF59 with those given a placebo injection. Having had success with combination medicines, the study hopes to show more conclusively the role of vaccine in a disease thought impossible to prevent. Previous research showed that dual use of HIV vaccines was 31.2% successful in a study of over 16,000 individuals.
‘”If an HIV vaccine were found to work in South Africa, it could dramatically alter the course of the pandemic.” Says Glenda Grey, CEO of the South African Medical research council.
The vaccine may play a significant role alongside other measures. Prevention through vaccine is an exciting development, but full coverage is not promised. Use of barrier methods (such as condoms) and avoiding high risk activities will still be at the forefront of disease prevention. Blood screening, early testing and public education have helped reduce global infection rates over recent years.
Regardless, the new vaccine may encourage a renewed and deeper interest in future vaccines. This will be welcome news to many living in endemic areas and those at greater risk.
What is HIV
Human Immunodeficiency virus is the name given to an infection characterized by progressive destruction of the immune system. The virus, spread predominantly by blood, targets and infects ‘T Helper cells’, one of many ‘signaler’ cells that our body uses to direct its defenses. By wiping out these cells, the body becomes susceptible to infection and over time enters a state of ‘immunodeficiency’ where it can no longer mount a response to common infections. It is at this time the body is said to have developed AIDS, an ‘Acquired Immunodeficiency Syndrome’.
What is placebo
A placebo drug is one that has no measurable or predicted therapeutic effect and forms a vital part of clinical trials. In a trial of new medicine, it is important to determine whether the effect seen by the new drug is indeed caused by the drug, or something else unknown. By giving some of the study participants a ‘placebo’, scientists can compare results directly by measuring response by the ‘test group’ compared to the ‘placebo’.
It is important that neither the study participants of investigators know who has a placebo and who has the drug in question in order to prevent bias.
Dr Ben Janaway MBChB // @drjanaway