A single injection every two months could protect women against HIV

Since Monday the world’s attention has been fixed on the announcement by Pfizer and BioNTech that their vaccine against the novel coronavirus was 90 percent effective in preventing infection.

As a result, news of another big breakthrough against another deadly virus flew largely under the radar.

Scientists announced that the drug Cabotegravir is 89 percent more effective than Truvada at reducing the risk of HIV infection in women, a process known as pre-exposure prophylaxis or more commonly- PrEP.

Why is that a big deal? Because traditional forms of PrEP, such as Truvada, come in pill form and must be taken daily in order to be effective. This requires an active effort to remember to take the tablets. 

Cabotegravir on the other, requires six annual injections taken at two month intervals, making it much easier to manage.

The World Health Organization (WHO) said: “While oral PrEP is highly effective in preventing HIV in women when taken as prescribed, some women find it difficult to take a daily tablet, and inconsistent use of oral PrEP reduces the prevention effect.”

It said trials were conducted across a broad area of southern and eastern Africa where HIV infections are high.

Officials at the world health body cautioned however that the drug would need to be further researched to ensure its effectiveness among teenagers and women who are pregnant or breastfeeding.

How does PrEP work?

PrEP describes a process in which anti-HIV drugs are taken before exposure to the HIV virus to prevent the pathogen from establishing enough of a foothold in the body to establish infection.

Truvada works by blocking enzymes that the HIV virus needs to make copies of itself and spread throughout the body.

Similarly, Cabotegravir, blocks an enzyme called integrase, which the virus needs to replicate.

PrEP has been widely adopted as one of the most effective ways of countering HIV transmission and therefore the spread of the virus, for which there is no known cure once infection takes hold.

It also works by making people already infected with HIV less likely to infect others by reducing the viral load in their bodies to a degree, which prevents it from being passed on to others.

HIV infection rates fall to 90 percent for sexual transmission and 70 percent for transmission through shared intravenous needles when an infected person is correctly following a PrEP course.

Around 38 million people across the world live with HIV and at least 32 million have died from HIV-induced illnesses since the start of the epidemic in the 80s.

In 2019, 1.7 million acquired the virus, down from a peak of 2.8 million in 1998, according to the UN.

The region worst hit by the epidemic is sub-Saharan Africa, which has infection rates of near or higher than 20 percent in a number of countries, including South Africa, Botswana, and Lesotho. Specific demographics, such as gay men and sex workers, are particularly affected across the world.

HIV does not kill directly but works by damaging and destroying CD4 T-Cells that are part of the body’s immune response system to infection and other illnesses.

Once a patient’s CD4 count is so low that the body can no longer fight off infection, they are considered to have Acquired immunodeficiency syndrome or AIDS.

AIDS is a life threatening condition that makes people infected with HIV susceptible to death through illnesses that would not normally easily occur in a healthy person, such as certain types of cancers and pneumonia. 

Left untreated, HIV infection can turn into AIDS within eight to 10 years, however antiretroviral drugs can keep viral loads low enough so that people can live normal lives, way into old age.