Forty years on, the world is edging closer to eradicating HIV

The photo resembles many others that have been flooding the internet for months. A young man, leaning back in a chair, waits with the sleeve of his left arm rolled up for the nurse to give him his jab. It was taken on 23 March at the General Hospital of Valencia and if it had been just another of the many similar photos, it might not have caused the reaction that followed, it would not have been shared more than 20,000 times.

“Today I have been vaccinated,” said the text accompanying the image, “But not against the coronavirus. I have been vaccinated against HIV.”

Almost in tandem with the global vaccination campaign against Covid-19, around 50 hospitals and research centres in Europe, the United States and Latin America are taking part in an international clinical trial sponsored by the pharmaceutical company Janssen to find a definitive vaccine against the last major pandemic of the 20th century.

Named Mosaico, the phase three trial has been underway since November 2019, but its progress has been overshadowed by the current health crisis. Its aim is to measure the new vaccine’s effectiveness in generating antibodies that prevent infection with HIV, the virus that causes AIDS. To do this, they need to test it on 3,800 volunteers, in this case men and transgender people who have sex with men, one of the main risk groups.

“Recruitment is going well. It’s an issue that has raised a great deal of interest. The level of awareness is very high in the LGBT+ community. In addition, the people who have published it on social media have helped to give the trial greater visibility,” says Vicente Descalzo, a doctor at the infectious diseases unit of the Vall d’Hebron Hospital, in Barcelona, one of the institutions taking part in the study. “Each volunteer will be monitored for two and a half years to see if the vaccine really offers protection. The idea is to help the body to learn and to develop an immune response,” says the doctor.

Phase three is the final stage to be completed before a vaccine can be marketed. If all goes well, and it proves to be effective, we will be closer than ever to eradicating a disease that, only a short time ago, was the leading cause of death in people between 25 and 44 years of age, a disease that has claimed 32 million lives in the last 40 years and that, still today, although more under control, continues to claim nearly 700,000 lives every year – more than 95 per cent of them in developing countries. We don’t know if the vaccine will be effective or not, but this is certainly one more step,” says Descalzo. “It’s very moving.”

A forty-year search

In June 1981, the first five HIV-related cases were detected in Los Angeles. Two years later, in 1983, scientists were able to isolate the virus for the first time. Since then, science has been searching for ways to combat it.

The first vaccine candidates emerged in the late 1980s, but all attempts failed, so complex is the virus and so astonishing its capacity to mutate. “The genetic variability of HIV is a thousand times greater than that of Covid-19. There is one type of virus in Europe and another in Africa. And its great variability is not only geographical, it can also be seen within the same area or even within the same person,” warns Descalzo.

The last time a clinical trial reached phase three was in 2009, in Thailand, and although that vaccine showed promising results – with 31.2 per cent efficacy – the attempt to replicate it in South Africa did not work. This time, the strategy is to combine two different vaccines, to inject a ‘mosaic’ of genetic material from the virus that includes the most common subtypes, so as to generate a more global immune response.

Half of the volunteers will be injected with this genetic combination, the other half with a placebo. “Over time, we will be able to see if there are fewer infections in the vaccinated group,” says the doctor from Vall d’Hebron Hospital.

For the communities most affected by the virus, the mere start of this new trial is, in itself, a symbol of hope. “We have been waiting for a vaccine for many years, we know that there have been many attempts, that it’s complex, due to the nature of the virus, but we are hopeful and happy that the research is continuing and that they are not throwing in the towel,” explains Ramón Espacio, president of CESIDA, the most representative body bringing together organisations addressing the issue of HIV and AIDS across Spain.

So far, more than US$15 billion (around €12.4 billion) have been invested in the search for a vaccine against HIV – mainly funded by the US and primarily by the public sector. These efforts have not been in vain.

The knowledge generated in the fight against HIV has been used to make faster progress in research on Covid-19 (a much simpler virus – in which US$39 billion, around €32 billion, were invested in 2020 alone), contributing to the approval, in less than a year, of what scientists have been pursuing for forty years in the case of HIV.

“Vaccination platforms that already existed and a lot of the knowledge already available have been used,” says Beatriz Mothe of the IrsiCaixa AIDS Research Institute. “The knowledge generated with Covid is now likely to help boost HIV research and speed up the development of other vaccine candidates, but it will require more investment, the same as that dedicated to Covid,” she points out.

The only long-term solution

In 2019, 1.7 million new HIV infections were reported globally. Although the virus is not as deadly as it used to be (life expectancy is generally good among people with HIV who are on antiretroviral treatment), the numbers are worrying in regions such as Eastern Europe, Central Asia and West Africa and could become even more so in the coming years, with the Covid-19 pandemic disrupting many care and treatment programmes.

One of the most recent and effective additions to the various preventative approaches, such as the use of condoms or microbicides, is known as “pre-exposure prophylaxis” (PrEP), a pill that, taken daily, can reduce the risk of contracting the virus by 90 per cent.

The problem with PrEP – as researcher Beatriz Mothe points out – is that, despite being a good option, “there are implementation challenges. It is not reaching everyone.”

One issue is its uneven territorial distribution. Another is that there are not enough centres or staff to administer the pills and monitor the patients. “In Spain, it was approved at the end of 2019, and there are still autonomous communities [regions] where PrEP is not yet available, whilst in others the waiting lists are very long,” says Espacio of CESIDA.

That is why the vaccine is so urgent. “PrEP is a strategy that provides good protection but it is, ultimately, a pill that has to be taken every day. In the long term, the vaccine is more implementable, because the immunity it provides protects you for years,” says Mothe.

“The vaccine is crucial because it means preventing everything that goes with having a chronic condition and taking lifelong medication,” agrees Espacio. “All the epidemics in history have been controlled with vaccines, and this is still an epidemic.”

Vaccines for all

If there is one place where a HIV vaccine is desperately needed, it is on the African continent, where the risk of mortality is currently the highest, especially among women. Adolescent girls aged 15 to 19 account for three out of every four new HIV cases in Sub-Saharan Africa.

Since 2017, another vaccine trial – the Invocodo study also sponsored by Janssen – has been underway in this area, involving 2,600 female volunteers, with results expected in 2022.

“It looks like we are getting closer, but so far we have always been disappointed,” Esther Casas, a member of the medical staff of Médecins Sans Frontières (MSF) in South Africa, tells Equal Times. “It’s true that we all want to see some light at the end of the tunnel, it would be fantastic, but, as medical staff, the first thing my colleagues and I think about is ‘who is going to have access to the vaccine’,” she adds.

If there is one thing that has become abundantly clear during the 40-year battle against HIV, it is that access to the various solutions is unequal. Treatments widely used in Europe and the US took more than a decade to reach Africa.

“Antiretrovirals were approved in 1986. But when I started working in Kenya, in 2004, antiretrovirals were just starting to arrive,” recalls Casas. “Many deaths and many new infections could have been prevented if more antiretrovirals had been available when they were needed.”

As the senior advisor on HIV for MSF points out, “It’s true that we’ve reached a better point, that pharmaceutical companies are working in coordination with generic medicine manufacturers to produce medicines more quickly and on a much larger scale.” But “there is always a gap between access in the countries of the North and the rest of the world, even now”, says the doctor. The current distribution of Covid vaccines – with high-income countries hoarding 87 per cent of doses – is perhaps the best illustration of this fact.

“We need to learn from our mistakes,” insist those on the frontline of this other global pandemic. “If a HIV vaccine is finally attained, it will require a great deal of coordination and political will. Above all, priority will have to be given to the communities with the largest number of patients and populations at risk, regardless of per capita income.”