UK Armed Forces personnel with HIV are to be declared fully fit and be deployable overseas, under new rules from the Ministry of Defence (MOD).
The new policy, introduced on Tuesday, also means anyone with HIV but no detectable virus can join the military, removing the final barrier to service.
The new rules particularly impact personnel who were diagnosed while already serving – previously they were then unable to deploy on certain operations as they were not deemed 'fully fit', but the new landmark policy means this barrier is being removed.
Serving personnel who are taking suppressive treatment for HIV, and whose blood tests show no detectable virus, will now be recognised as fully fit for all service.
This announcement follows the Government's policy changes made on World Aids Day in 2021 to allow those taking Pre-Exposure Prophylaxis (PrEP) medication to prevent HIV infection to join the military.
Chief of Defence People, Lieutenant General James Swift said: "Our people are our greatest asset and as part of the drive to modernise our Armed Forces we are making these long-overdue policy changes so people with HIV, but no detectable virus, are now able to join the military and those serving will be declared fully fit.
"This welcome change in policy is a recognition of the superb medical advancements that have been made and the decisive work by those that helped to bring about these changes.
"We will continue to ensure that all our people have the best experience possible, where their health and wellbeing is prioritised, and they can serve with pride and feel valued and supported in a modern Armed Forces."
Watch: In December 2021 the changes to break down barriers for HIV-positive military candidates were announced.
The change was sparked by Lieutenant Commander Oliver Brown, a Warfare Officer in the Royal Navy, who has been serving for 11 years.
After being diagnosed with HIV and realising he was then possibly prevented from certain deployments, he started working to have the rules changed.
Lt Cdr Brown said: "From today, I can be considered fully fit by the Royal Navy for the first time since I told them about my HIV diagnosis.
"Being labelled as limited deployable made me question myself and doubt my capability – it took a toll on my mental health. The biggest thing about this change is knowing that no-one else will feel how I did.
"The message is loud and clear – people living with HIV are not limited in any way. I take one tablet a day which makes my HIV undetectable and... I can't pass it on."
He added: "There is no reason why I, or anyone else, should be restricted in the Armed Forces and today's change reflects that reality."
The change comes as the Civil Aviation Authority (CAA) announced it has changed the rules that meant pilots who disclosed they had HIV were no longer required to undergo cognitive testing to assess their mental abilities.
This rule does still apply within the military, although work is under way to change this.
Ian Green, Chief Executive at Terrence Higgins Trust, said the policy change was a sign of "how far we've come".
"It's crucial it is now properly implemented to see the real-life impact of this momentous change for both existing serving personnel and those wishing to join."
Mr Green added: "We also need to see an end to the final barrier in place which stops military aircrew and air traffic controllers taking HIV prevention pill PrEP to protect themselves against the virus.
"This must be reviewed and implemented as soon as possible."
The new policy will ensure that people living with HIV will be provided personal medical supplies to last throughout their deployment. If this should get lost or damaged, it can be replaced using the same process that already exists for other personnel needing regular medication.