With More Vaccines Secured, Biden Warns of Hurdles to Come

WASHINGTON — The Biden administration said Thursday it had secured 200 million more doses of coronavirus vaccines, enough to inoculate every American adult, but President Biden warned that logistical hurdles would most likely mean that many Americans will still not have been vaccinated by the end of the summer.

The additional doses amount to a 50 percent increase in vaccine, and will give the administration the number of doses that Mr. Biden said last month he needs to cover 300 million people by the end of the summer. But it will still be difficult to get those shots into people’s arms. Both vaccines are two-dose regimens, spaced three and four weeks apart. Mr. Biden lamented the “gigantic” logistical challenge he faces during an appearance at the National Institutes of Health. He also expressed open frustration with the previous administration.

“It’s one thing to have the vaccine,” Mr. Biden said. “It’s another thing to have vaccinators.”

The Department of Health and Human Services said Pfizer and Moderna would each provide 300 million doses by the end of July in “regular increments.”

The administration is looking toward a step-by-step process. Dr. Anthony S. Fauci, the government’s top infectious disease expert, predicted on