The HIV/AIDS disease in many parts of the world is considered a pandemic, having led to the death between 1981-2009 of almost 30 million people. But after more than four decades, redemption seems to have come.
Clinical trials in South Africa and Uganda have shown that a vaccine every six months provides 100% protection for young women against HIV infection.
Specifically, the scientists tested whether the lencapavir vaccine would provide better protection against infection with the virus than two other drugs, both daily pills. All three drugs are pre-exposure prophylaxis drugs (“PrEP” stands for Pre-Exposure Prophylaxis).
These two pills are Truvada F/TDF, a daily pill that has been widely used for a decade or so, and the newer Descovy F/TAF, one just as effective as the previous one.
Lencapavir (Len LA) is an inhibitor of capsid fusion. It interferes with the HIV capsid, a protein shell that protects HIV’s genetic material and the enzymes needed for replication. It is given by injection once every six months.
Superior to existing drugs
The trial involved a massive sample of 5,000 women at three sites in Uganda and 25 sites in South Africa to test the effectiveness of lencapavir and two other drugs.
Thus, the scientists found that during the randomized phase of the trial none of the 2,134 women who received lencapavir became infected with HIV. There was, that is, 100% effectiveness.
In comparison, 16 of 1,068 women (or 1.5%) who received Truvada (F/TDF) and 39 of 2,136 (1.8%) who received Descovy (F/TAF) became infected with HIV.
“This breakthrough gives great hope that we have a proven, highly effective prevention tool to protect people from HIV,” Dr Linda-Gail Becker, principal investigator for the South African arm of the study and former president of the International AIDS Society.
There were 1.3 million new infections worldwide last year. Although this is less than the 2 million infections seen in 2010, it is clear that at this rate we are not going to reach the new HIV infection target set by UNAIDS for 2025 (less than 500,000 worldwide) or possibly even the goal of ending AIDS by 2030.
For young people, the daily decision to take a pill or use a condom or take a pill at the time of intercourse can be very difficult.
HIV scientists and activists hope that young people may find that making this “prevention decision” just twice a year can reduce unpredictability and barriers.
For a young woman who struggles to make an appointment at a clinic in a city or who can’t keep pills down without facing stigma or violence, an injection just twice a year is the option that could keep her free from the HIV virus.
However, as the scientist reports, testing is also ongoing in other groups, such as cisgender men and transgender and non-binary people who have sex with men.
It is important to conduct trials between different groups because we have seen differences in effectiveness. Whether the sex is anal or vaginal is important and can have an impact on effectiveness.
The randomized controlled trial, sponsored by drug developer Gilead Sciences, tested several things.
As stated by the company, within the next two months it will submit the dossier with all the results to a number of regulatory authorities of countries, in particular the regulators of Uganda and South Africa.
The World Health Organization will also review the data and may issue recommendations, and scientists hope the new drug will be adopted into WHO guidelines.
Since price is a critical factor in ensuring access and distribution in the public sector where it is sorely needed, the company said it will offer licenses to companies that make generic drugs, another critical way to lower prices.
