A trial that was testing an experimental vaccine for HIV has shut down because the vaccine was not working, according to The New York Times.
The trial was conducted by the National Institutes of Health's National Institute for Allergy and Infectious Diseases in South Africa. It began in 2016.
The trial included 5,407 young adults. Early results showed that 129 participants who received the experimental vaccine contracted HIV infections, compared to 123 participants who received a placebo and contracted HIV.
Researchers said that the trial vaccine was not making people more vulnerable to HIV and the fact that the trial vaccine pool had six more infections was likely due to chance.
The experimental vaccine included canarypox, a bird virus that can be injected into the human body but does not multiply in it, which was used as a delivery mechanism to deliver a protein found in HIV into the body. Researchers hoped the immune system would learn to recognize the protein and begin creating protective antibodies.
"We hoped this vaccine candidate would work — regrettably, it does not," said Anthony Fauci, MD, director of the National Institute for Allergy and Infectious Diseases, to the Times. "Research continues on other approaches to a safe and effective HIV vaccine, which I still believe can be achieved."