James Krellenstein, the founder of the AIDS advocacy group PrEP4All and an organizer of the Montreal protest, said the appointments were long overdue. He described Dr. Daskalakis as an “excellent physician and epidemiologist” who “has the trust of so many in the gay and trans community.”

“Every single one of my friends who has gotten monkeypox now attempted to get vaccinated in late May or early June,” Mr. Krellenstein said, adding that he knew a dozen people who were infected. Because of the federal government’s missteps, he said, they were “unable to get vaccinated and unable to protect themselves, and they are sick and in excruciating, inhuman pain.”

Until now, the response has been coordinated largely by Dr. Raj Panjabi, the director for global health security and biodefense on the National Security Council, whose responsibilities include guarding against infectious disease threats. Dr. Ashish K. Jha, the White House coronavirus response coordinator, has also played a role, as have Dr. Jennifer McQuiston, a C.D.C. official; Dawn O’Connell, the assistant secretary for preparedness and response at the Department of Health and Human Services; and Xavier Becerra, the health secretary.

Centering the response operation at the White House gives the administration more flexibility to coordinate efforts across a range of agencies that might be involved, including FEMA, the Health and Human Services Department and the Department of Homeland Security. It also creates a designated team that has no responsibilities other than to combat monkeypox — a move that makes sense, said Dr. Anthony S. Fauci, Mr. Biden’s chief medical adviser.

“Putting together someone who has extensive experience in implementation of public health programs, the way Bob Fenton did with the distribution of Covid vaccines, with someone like Demetre Daskalakis, who not only is an experienced infectious disease and public health physician, but who also has very strong, credible ties to the community, is a very important addition to the overall monkeypox response,” Dr. Fauci said in an interview.

An early-morning statement from the White House said the two men’s responsibilities would include “equitably increasing the availability of tests, vaccinations and treatments.”