An experimental HIV vaccine being developed by Johnson and Johnson has been scrapped after early data showed it didn’t work.
It’s the latest blow in the search for a cure for the disease that still kills 2,000 people in the United States every year despite highly effective drugs being available that can allow people to live symptom-free and as long as if they did not have the virus.
Independent safety experts called for a halt to J&J’s trial after finding as many new HIV infections in those who received the vaccine as those who got a placebo.
Researchers at the New Jersey-based company said the results were ‘disappointing,’ but that they were determined to find new treatments.
At least five HIV vaccines have now failed, campaigners say after another Janssen shot against the virus was shelved in August 2021.
A trial of an HIV vaccine by Janssen has been abandoned after it failed to stop people from catching the virus (stock image)
The phase three trial included 3,900 men who have sex with men from eight countries including the US. It was backed by the National Institutes of Health.
Participants were aged 18 to 60 years old and joined in 2019.
They were split into two groups and given either a placebo — or fake vaccine — or the experimental vaccine administered in four doses over a year.
All were also offered pre-exposure prophylaxis (PrEP) for the duration of the study, which can prevent new HIV infections.
Scientists had hoped the experimental vaccine would trigger broad immunity against a range of HIV strains.
But a review by independent safety experts found new HIV infections were emerging in both groups at roughly the same rate, reports Stat News.
The experimental vaccine used a ‘mosaic’ of antigens/immunogens — which viruses use to invade cells — from several HIV strains to trigger immunity against the virus.
The final two doses also included a protein envelope from HIV, which the virus uses to contain its DNA.
It was delivered to patients using a weakened common cold virus — adenovirus — which was also used in the company’s single-shot Covid vaccine, which is no longer recommended for use in the US.
Dr Penny Heaton, the head of Janssen’s global team of researchers, said: ‘We are disappointed with this outcome and stand in solidarity with the people and communities vulnerable to and affected by HIV.
‘We remain steadfast in our commitment to advancing innovation in HIV, and we hope the data from Mosaico will provide insights for future efforts to develop a safe and effective vaccine.’
At least five experimental HIV vaccines have now failed to trigger protection against the virus, the executive director of the AIDS Vaccine Advocacy Coalition Mitchell Warren told STAT News.
‘I’m not sure we know exactly where the next big investment is going to come from because there’s no obvious vaccine candidate in HIV that is next up in our efficacy pipeline,’ the said.
‘This is another reason why this result is disappointing. This was the last true product in development. And the other activities in the field, which are very exciting… [are] quite [far off].’
Janssen also had to abandon its phase 2b trial of a similar HIV vaccine when data also showed that it had not worked.
Known as the Imbokodo trial, this was carried out on women in sub-Saharan Africa.
Scientists at Moderna are also looking to make an mRNA vaccine against HIV — the same technology deployed in Moderna and Pfizer’s Covid shots.
But scientists say a new approach may be needed to trigger protection against HIV, rather than a new way of delivering antigens.
HIV has proved a difficult enemy for scientists because the virus constantly changes its antigens, making it hard for the immune system to detect and fight off.
There are already nine strains of HIV known, with each bridging into several different substrains. Scientists are constantly finding new ones.
BUT highly effective drugs exist such as PrEP, which reduces the risk of catching HIV by about 99 percent if someone is exposed to the virus while taking the drug.
There is also — post-exposure prophylaxis — is also available for people who are or believe they have been exposed to HIV. It is about 80 percent effective at preventing infections if taken consistently and correctly.
The virus is no longer a death sentence for Americans, with treatments available that can suppress it to below-detectable levels.
About 1.2million Americans have HIV, which disproportionately affects gay and bisexual men in the country.
Cases in all groups have trended downwards in recent years, estimates show, but about two-thirds of new infections are still being detected among gay and bisexual men every year.
Latest data goes up to 2020, but it is feared the interruption to services over the pandemic.