The Biden administration says it will add 1.8 million doses of monkeypox vaccine to the U.S. supply as it struggles to contain the largest-ever outbreak of the viral disease outside of Africa. Last week the Food and Drug Administration approved a plan to stretch the vaccine supply by administering one-fifth of a normal dose per patient. Critics say there’s limited data showing whether the strategy will be effective. The U.S. leads the world in confirmed monkeypox cases with over 14,000 — more than a third of the worldwide total — though disease experts say the true number of infections is likely far higher. Public health data show Black men have been disproportionately affected by monkeypox but are receiving the vaccine at much lower rates than other groups.