Darin Seehafer
Darin Seehafer
Clinical Scientist, PRA Vaccine Solutions

December 1st is World AIDS Day and while in the early 1980s there wasn’t anything to celebrate, in recent years HIV/AIDs has become a much more manageable disease, at least in the developed world.

Once again, as with so many diseases, treatment options, access, and disease burden fall along societal lines. In developing countries AIDS is still considered a major health epidemic, but access to antiretrovirals are not at the levels they need to be, so while rates of infection have come down, the disease still persists.

Dr. Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases at the U.S. National Institutes of Health, stated earlier this year, “We have the tools right now to end AIDS…We are not there yet, but we greatly helped by an HIV Vaccine…Even a vaccine that was 50-60% effective together with the other advances we have made we could turn the trajectory of the disease and end the epidemic as we know it.”

World AIDS Day takes place on the 1st December each year. It’s an opportunity to highlight the success of worldwide efforts to combat HIV/AIDS, as well as the importance of continued support for these efforts. Founded in 1988, World AIDS Day was the first ever global health day. The 2017 theme for UNAIDS is My Health My Right and for WHO is Everybody Counts.

While much progress had been made since the beginning of the AIDS epidemic, the numbers are still staggering. According to UNAIDS:

  • 7 million people are currently living with HIV/AIDS worldwide
  • 1 million children are living with HIV/AIDs worldwide, most of whom were infected by their HIV-positive mother
  • 8 million individuals worldwide became newly infected with HIV in 2016
  • 9 million HIV-positive people are accessing antiretroviral therapy (ART) globally
  • 1 million people died from AIDS-related illnesses in 2016 (35 million total since the beginning of the epidemic)

The data shows that the majority of people living with HIV are in low and middle-income counties. Sub-Saharan Africa is the most affected region, with an estimated 25.6 million people living with HIV in 2015. About 66% of new HIV infections in 2015 occurred in this region. When performing a root cause analysis, it becomes clear that the primary drivers for these trends are access to quality healthcare and to life-saving antiretroviral treatments (ART), along with proper testing.

Another alarming fact that can be seen in the data is the increase in the number of deaths in Eastern Europe and Central Asia along with the Middle East and North Africa.

Aids day graph
AIDS-related deaths, by region, 2000–2016 (image courtesy of UNAIDS report)

Since 2001, new HIV infections have risen by 35% for the Middle East and North Africa. In addition, AIDS-related deaths increased by 66% (2005-201) in comparison with a worldwide fall of 35%. This could be because this region has the lowest ART coverage of any region in the world at 17%.

This is in sharp contrast to the fact that the Middle East and North Africa (MENA) region has one of the lowest HIV prevalence rates in the world (0.1%), compared to Sub-Saharan Africa, which has the highest HIV prevalence rate of all regions (7.1%).

So where are the vaccines?

The answer, unfortunately, is not definitive. Vaccine trials conducted in Thailand were able to produce a vaccine that was nearly 30% effective. This is about half as effective as needed for it to be a viable part of the solution to this epidemic.

Currently, there are additional trials being conducted in South Africa. The APPROACH and TRAVERSE studies (sponsored by Janssen Vaccines & Prevention B.V. and supported by the NIAID) use a mosaic vaccine designed to induce immunological responses against a wide variety of HIV subtypes (clades) responsible for HIV infections around the world.

The APPROACH study involved nearly 400 volunteers in the United States, Rwanda, Uganda, South Africa, and Thailand who were randomly assigned to receive one of seven experimental vaccine regimens or a placebo.

APPROACH found that different mosaic vaccine regimens were well-tolerated and capable of generating anti-HIV immune responses in healthy, HIV-negative adults. The conclusion drawn from APPROACH study was that moving forward a regimen comprising two Ad26 mosaic primes and two boosts with Ad26 mosaic and clade C gp140 would be used.

TRAVERSE trial is comparing Ad26-based regimens containing three mosaic antigens (trivalent) with Ad26-based regimens containing four mosaic antigens (tetravalent). Results from TRAVERSE are expected in late 2017.

So, until we have an effective vaccine, we will continue to monitor the progress of this important program and maintain hope for the day we see an end to this horrible epidemic.

You may also be interested in: