disappointing

Major HIV vaccine trial halted after proving ineffective

A man receives the monkeypox vaccine
Posed by model (Photo: Shutterstock)

Disappointing news in the neverending search for a vaccine against HIV. Pharma giant Johnson & Johnson announced yesterday that it was pulling the plug early on its latest trial after it became clear it wasn’t proving effective.

Janssen (J&J’s research arm) partnered with the National Institute of Allergy and Infectious Diseases (NIAID).

A spokesperson for NIAID said, “It’s not the outcome we had hoped for, unfortunately. The development of a safe and effective HIV vaccine has been a considerable scientific challenge, but we will learn from this study and continue forward.”

J&J used similar technology to its Covid-19 shot. As part of the Mosaico Study, 3,900 gay men and transgender people received the HIV vaccine or a placebo. All participants had previously declined to take PrEP. The study was due to end in early 2024.

Mitchell Warren, director of the prevention advocacy organization AVAC, commented: “We always hope that efficacy trials will show positive results that lead to new prevention options… [but] the hard truth is the science of HIV vaccine development is extremely challenging.”

Related: Here’s why COVID-19 has a vaccine after 1 year and HIV doesn’t after nearly 40 years

The challenges of producing a HIV vaccine

HIV mutates rapidly and is skilled at evading the body’s immune system. As a retrovirus, it can hide in the very DNA of our cells. This makes it impossible for our own immune system to locate the virus.

For this reason, attempts to produce a vaccine have so far failed. Although this latest formulation showed some efficiency in earlier trials, that effectiveness was clearly not good enough for experts to consider releasing it to the market.

Fortunately, PrEP is highly effective at preventing HIV infection. Experts believe that long-lasting injectable or implantable PrEP might prove a more realistic aid in ending HIV transmission.

Related: FDA gives approval for human trial of potential HIV cure

Dr. Penny Heaton of Janssen said of the latest trial failure, “We are disappointed with this outcome and stand in solidarity with the people and communities vulnerable to and affected by HIV.

“Though there have been significant advances in prevention since the beginning of the global epidemic, 1.5 million people acquired HIV in 2021 alone, underscoring the high unmet need for new options and why we have long worked to tackle this global health challenge. 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.”