The pace of U.S. vaccinations has slowed considerably, hampered by snow and power outages.

© Bryan Woolston / Reuters
The UPS air hub in Louisville, Ky., Closed last week due to extreme weather conditions.

The Covid-19 vaccination rate in the United States, which had accelerated after a chaotic start, fell rapidly after a winter storm swept across much of the country, closing vaccination sites and delaying shipments of millions of doses.

About 1.52 million doses of the vaccine are given per day, according to a New York Times database. While still above President Biden’s target, it is the lowest rate since February 8.

The country rushed to vaccinate as many people as possible before more contagious and possibly deadly variants of the coronavirus became dominant, and the figure was well above the president’s target of 1.5 million doses during many days. It peaked at 1.7 million on February 16 before a severe winter storm hit states coast to coast. Bad weather delayed shipments of vaccine supplies from two hubs: a FedEx center in Memphis and a UPS site in Louisville, Ky.

More than 2,000 vaccination sites were in areas with no power, according to the Federal Emergency Management Agency. Many were not only forced to shut down, but had to rely on generators to keep doses at the ultra-cold temperatures they needed to keep them from spoiling.

New York City has fewer than 1,000 first doses of Covid-19 due to shipping delays caused by snowstorms across the country, the city reported on Saturday. Mayor Bill de Blasio said New York City had delayed scheduling 35,000 appointments for the first dose due to the shortage.

The storm stacked six million doses, or about three days of shipping delays, blocking appointments across the country, White House pandemic adviser Andy Slavitt said at a conference with hurry.

States have cleared part of the backlog with existing stock, Slavitt said. Of the six million doses, 1.4 million were already in transit on Friday, he added, with the rest expected to be delivered next week.

“We are asking vaccine delivery sites to further extend their hours of operation and offer additional appointments and try to postpone vaccinations over the next few days and weeks as the supply arrives considerably. “Slavitt said Friday.

The bottlenecks and delays have come just as states have expanded access to vaccines to more groups, despite a limited supply not growing enough to keep pace.

California Gov. Gavin Newsom said that starting March 1, the state will reserve 10% of its first doses of the vaccine for teachers and school employees, after expanding access to all Californians with chronic diseases and disabilities.

Some states have resumed vaccinations. Texas, after an icy storm left millions of people without power and water, has reopened the inoculation sites. The state has been allocated nearly 600,000 first doses of the vaccine for the coming week, according to the state’s health department, compared to around 400,000 first doses for the week of February 15.

Doses that were supposed to be delivered this week are still waiting to be shipped to Texas from out-of-state warehouses, health officials said. Missed doses are expected to be delivered in the first half of this week.

In Dallas, a major vaccination center at Fair Park will reopen on Sunday, but sites in Austin remain closed.

Houston Mayor Sylvester Turner said on “Face the Nation” on Sunday that vaccinations had resumed there and that a FEMA site would open on Monday with the potential to administer injections to 6,000 people a day during the six to the next eight weeks. He estimated that the city could vaccinate more than 100,000 people in the coming week. “People are resilient,” he said. “I am very proud of the people of the city of Houston for the way they have come together.”

New York State is still making appointments to open new mass vaccination sites in Brooklyn and Queens on Wednesday in partnership with FEMA.

State officials said they received 40% of their vaccine allowance for the week and expected the rest to be distributed on Sunday.

The new sites, at Medgar Evers College in Brooklyn and York College in Queens, are open to residents of certain zip codes only and are intended to increase low vaccination rates in communities of color. Data released Tuesday showed drastic disparities between vaccination rates in whiter areas of New York City compared to predominantly black neighborhoods.