A US investigational HIV vaccine regimen was safe but did not provide protection against HIV acquisition, according to a statement from the US National Institute of Health (NIH).

The trial, called HPX3002/HVTN 706 or "Mosaico," began in 2019 and involved 3,900 volunteers aged between 18 to 60 years in Europe, North America and South America, Xinhua news agency reported.

The trial was conducted by the HIV Vaccine Clinical Trials Network, based at the Fred Hutchinson Cancer Research Centre in Seattle.

The experimental vaccine regimen was developed by Janssen. It was based on "mosaic" immunogens -- vaccine components featuring elements of multiple HIV subtypes -- with the goal of inducing immune responses against a wide variety of global HIV strains, according to the NIH on January 18.