The fight against AIDS and HIV is now in its fourth decade, but many continue to work to ensure the cause doesn't lose its urgency "because we know so many people still need our help," Mayor Bill de Blasio said Sunday, speaking to about 30,000 people gathered in Central Park for the GHMC AIDS Walk, according to organizers.

They mayor touted a new initiative with Gov. Andrew M. Cuomo that seeks to help low-income New York City residents living with HIV or AIDS.

The measure, part of the state budget, caps the rent of those who qualify at 30 percent of their income. The housing subsidy provides the residents with a "measure of justice," de Blasio said.

This story has been updated to reflect organizers’ estimates that 30,000 people attended Sunday’s AIDS walk.