Alphonso David, president of Human Rights Campaign (HRC), has called on President Donald Trump's son, Donald Trump, Jr., to apologize for a “vile HIV and AIDS tweet.”

The president's son responded to an op-ed on dating HIV-positive people published in the LGBT blog Queerty ahead of World AIDS Day, celebrated on Sunday, December 1.

Titled “What you stand to lose by not having sex with people with HIV,” the essay argued that a person's HIV status should not stand in the way of a potential partner given that an undetectable viral load means a person cannot transmit the virus.

“Well I can think of one thing,” Trump responded in tweeting the article.

David called the tweet “absolutely disgusting.”

“Trump Jr. just proved again what we already knew – that he, his father and the Trump-Pence administration don’t care about people living with HIV, are undermining competent care and have no understanding of people living with HIV,” David said. “Trump Jr.’s absolutely disgusting and ignorant tweet only serves to perpetuate the stigma faced by people living with HIV, which HRC and LGBTQ advocates have fought so long to end. Trump Jr. must apologize. And Trump and Pence must put their money where their mouth is and actually sufficiently fund the domestic initiatives aimed at ending the epidemic they claim to be combating.”

(Related: Trump's World AIDS Day proclamation again omits LGBT people.)