In Europe and America Janssen is conducting the Mosaic study, which looks very promising, with cis and trans men who are gay or bisexual; that is, they sleep with other men. In fact, the Johnson & Johnson subsidiary has also been one of the pharmaceutical companies to release a coronavirus vaccine. However, in as opposed to their successes has also arrived a failure: the HIV vaccine that Janssen was testing in several countries in Africa. But how has this clinical trial been? What was it and where was it tested? And above all, Why is it considered a failure?
Let’s talk about the clinical trial. The study, called Imbokodo, was being conducted with young women in sub-Saharan Africa. More specifically in countries like Malawi, Mozambique, South Africa, Zambia and Zimbabwe. Since 2017, 2,600 women between the ages of 18 and 35 have participated in the research, who received placebo or the HIV vaccine. Why has it been tested on women? The answer is found in the data, since women and girls accounted for 63% of new HIV infections in 2020 in this region, according to El Mundo.
Poor efficacy of the HIV vaccine
Janssen found that their HIV vaccine was only 25% effective in preventing infection
Now, the clinical trial has been stopped because Janssen has observed that its HIV vaccine offered only one 25% effective in preventing infection. Recall that the Janssen coronavirus vaccine is 66.3% effective in preventing the disease (and much more in preventing hospitalizations and deaths).
“Despite our disappointment that the vaccine candidate will not provide a sufficient level of protection against HIV infection In the Imbokodo trial, the study will provide important scientific insights in the continuing search for a vaccine to prevent HIV, “said Paul Stoffels, Chief Scientific Officer, Johnson & Johnson.
Despite what happened with this trial, it must be reiterated that it is very different from the one currently being carried out in various American and European countries; among them in Spain. This study will be in progress, in principle, until March 2024. And then we will know if the other Janssen vaccine is a success or it also fails.
A very complex virus
The vaccine for HIV, the virus that causes AIDS, is very difficult to find due to the complexity of the virus itself. Unlike SARS-CoV-2, this other virus is special for two reasons: high genetic variability and the cells it attacks. In other words, HIV mutates much more easily than coronavirus. This means that you can’t take a protein, as has been done with the coronavirus spike, to make the vaccine and with that is enough. It has not been possible until now; but the researchers are still working.
On the other hand, it is necessary to differentiate between two types of vaccines that are being developed. Vaccines are used to prevent the spread of disease. However, they are also trying to produce what are known as functional vaccines, that is, they serve to cure HIV infection. In this second case, there is another difficulty: HIV reservoirs. That is, the places where the virus hides and waits to be able to re-infect. This is an added difficulty in finding a cure.
Ultimately, this failure of Janssen to create an HIV vaccine evidences that there is still a lot of work to do. Some may wonder why we do not already have a vaccine against this virus and against the coronavirus. But it is that HIV is very different from SARS-CoV-2 and much more difficult to find a vaccine that prevents infection and even a cure. But research is progressing and scientists are also learning from failure. It is not bad news because it brings us closer to the goal.