An experimental HIV vaccine being developed by Johnson and Johnson has been scrapped after initial data showed it didn’t work.
It’s the latest blow in the quest for a cure for the disease that continues to kill 2,000 people in the United States each year, despite the availability of highly effective drugs that allow people to live symptom-free lives as long as they don’t have the virus. .
Independent safety experts called for J&J’s study to be halted after finding an equal number of new HIV infections among those given the vaccine and those given a placebo.
Researchers from the New Jersey-based company said the results were “disappointing” but they were determined to find new treatments.
At least five HIV vaccines have now failed, campaigners say after another Johnson and Johnson shot against the virus was suspended in August 2021.
An HIV vaccine trial by Johnson and Johnson has been halted after it failed to prevent people from contracting the virus (stock image)
The phase three study included 3,900 men who have sex with men from eight countries, including the US. It was supported by the National Institutes of Health.
The participants were between the ages of 18 and 60 and participated in 2019.
They were split into two groups and given either a placebo – or a dummy vaccine – or the experimental vaccine in four doses over a year.
All were also offered pre-exposure prophylaxis (PrEP) for the duration of the study, which may prevent new HIV infections.
Scientists had hoped that the experimental vaccine would induce broad immunity against a range of HIV strains.
But a review by independent safety experts found that new HIV infections were emerging at about the same rate in both groups, Stat News reports.
The experimental vaccine used a ‘mosaic’ of antigens/immunogens – which viruses use to enter cells – from different strains of HIV to generate immunity against the virus.
The last two doses also contain an HIV protein coat, which the virus uses to contain its DNA.
It was administered to patients taking 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 the vaccine maker’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 Mosaico’s data will provide insights for future efforts to develop a safe and effective vaccine.”
At least five experimental HIV vaccines have now failed to activate protection against the virus, AIDS Vaccine Advocacy Coalition executive director Mitchell Warren told STAT News.
“I’m not sure we know exactly where the next big investment will come from, because there’s no obvious vaccine candidate for HIV that’s next in our efficacy pipeline,” he said.
This is another reason why this result is disappointing. This was the last real product in development. And the other activities in the field, which are very exciting… [are] rather [far off].’
Johnson and Johnson also had to stop their phase 2b trial of a similar HIV vaccine when data also showed it hadn’t worked.
Known as the Imbokodo process, this was performed on women in sub-Saharan Africa.
Scientists at Moderna are also looking for an mRNA vaccine against HIV — the same technology used in Moderna and Pfizer’s Covid shots.
But scientists say a new approach may be needed to kick-start protection against HIV, rather than a new way to deliver antigens.
HIV has proven to be a difficult foe for scientists because the virus is constantly changing its antigens, making it difficult for the immune system to detect and fight against.
Nine strains of HIV are already known, each of which passes into different substrains. Scientists are constantly finding new ones.
BUT there exist highly effective drugs such as PrEP, which reduces the risk of HIV by about 99 percent if someone is exposed to the virus while taking the drug.
There is also post-exposure prophylaxis available for people who have been or are believed to have been exposed to HIV. It is about 80 percent effective in preventing infections when taken consistently and correctly.
The virus is no longer a death sentence for Americans, with available treatments that can suppress it below detectable levels.
About 1.2 million Americans have HIV, which disproportionately affects gay and bisexual men in the country.
Cases across all groups have been on a downward trend in recent years, estimates show, but about two-thirds of new infections are still diagnosed in gay and bisexual men each year.
The most recent data goes to 2020, but there are fears of service disruption during the pandemic.