Few Americans receive the full regimen of monkeypox vaccines.

The head of the U.S. Centers for Disease Control and Prevention (CDC) said Friday that very few people in the United States have received a full series of monkeypox vaccinations.

CDC Director Rochelle Walensky said the vast majority of Americans who have received a first dose of the vaccine have not yet received their second dose, even though they are eligible.

She said at a White House briefing Friday that nearly 97% of vaccinations administered so far have been first doses.

Walensky said the vaccine was initially difficult to get, but that supplies have now been replenished.

Earlier this month, the U.S. Food and Drug Administration (FDA) allowed the vaccine to be injected in smaller doses to stretch supplies.

The Biden administration says it has shipped enough vaccine for at least 1.6 million doses to jurisdictions across the United States.

CDC data show that about 10% of monkeypox vaccine doses have been given to blacks, even though they account for one-third of cases in the United States.

The rate was compiled from 17 U.S. states and two cities.

Walensky said the CDC has taken steps to make the vaccine more accessible to blacks and other minorities. She said vaccines and educational materials will be available at two upcoming events - the Black Pride Festival in Atlanta and Southern Decadence in New Orleans.

Walensky said the agency is beginning to roll out such pilot projects and that "they are working."

Most cases of monkeypox in the United States have occurred in gay men, but health officials have stressed that anyone can contract the virus.

More than 16,000 people have contracted the virus in the United States, more than in any other country.

Walensky noted that the spread of the virus is declining in several major U.S. cities.

"We are watching this unfold with cautious optimism, and we are really confident that a lot of our harm reduction messages and our vaccines are getting through and working," she said.

Across the United States, monkeypox cases continue to rise. However, authorities say the pace of the outbreak appears to be slowing.

On Thursday, the World Health Organization said the number of monkeypox cases worldwide dropped 21% last week.

The WHO said cases in Europe appear to be slowing, but warned that infections in the Americas "continue to rise steeply."

"In Latin America in particular, inadequate education efforts and lack of access to vaccines are fueling the outbreak," WHO Director General Tedros Adhanom Ghebreyesus said at a news conference.

Monkeypox has been endemic in parts of Africa for decades, but cases have been reported from around the world since May.

The virus is usually transmitted through skin-to-skin contact with the lesions of an infected person. It can also be transmitted through contact with an infected person's clothing or bedding.

Some information for this report came from The Associated Press and Reuters.