Harry, who turns 32 on Thursday, visited Mildmay Mission Hospital in east London last Friday, a few days after he had returned from southern Africa, where he was on the front lines of elephant conservation work.
In 1989, Diana memorably shook hands with an AIDS patient at Mildmay and kissed him on the cheek – a gesture that went a long way to highlighting the fight against the illness.
During last week’s visit, a follow-up to the public one he made last December – Harry was able to spend more time talking with staff and patients and continue building his knowledge.
“He had a chance to speak to staff there for a bit longer,” a spokesman for the prince tells PEOPLE. “He met with patients and spent some time learning a bit more about the work there.
“He is continuing to learn more about HIV as a virus, and he was able to talk to them about his work on testing, which he is very interested in.”
In July, Harry publicly took an HIV test to encourage others to do the same.
Juley Ayres, communications manager at Mildmay, tells PEOPLE, “Many of our patients feel afraid to disclose the fact that they are living with HIV because of stigma, and this can cause enormous anxiety. Stigma and discrimination is cited as one of the main reasons why people are reluctant to get tested, disclose their HIV status and take antiretroviral drugs.
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“As an organization, we are deeply impressed and heartened to witness the work Prince Harry is doing to break down stigma, encourage testing and raise HIV awareness. We feel privileged to be able to support this work in any way we can.”
His quiet visit last Friday, which media weren’t invited to, matches the way his mother worked. When he was there last December, Harry remarked that he couldn’t believe how Diana, who died in 1997, had managed to come so often in secrecy. She visited 17 times – only three times in an official capacity.
Harry asked, “How on earth did she get away with sneaking in and out?’ and said, ‘If only I could do that!’ ” said Kerry Reeves-Kneip, who showed the prince around that day.
“He said it was very important for him to come here. This was a very important place to her and she made a number of visits here.”
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Reeves-Kniep told PEOPLE that the prince had an “absolutely amazing” touch with patients and staff alike.
“He really wanted to hear the patients’ stories and their
journey,” he said.
Later in the fall, Harry will travel to the Caribbean on behalf of his grandmother Queen Elizaebeth and will spend time in St. Kitts and Nevis, where he vacationed with mom Diana and brother Prince William in the early 1990s.