The US government is blocking states from ordering Johnson & Johnson's COVID-19 vaccine so they can clear their backlog of unused doses

• The government has blocked any shipments of Johnson & Johnson's vaccine, health officials told the WSJ.
• States already have stockpiles of the single-dose J&J shot, and vaccination rates are falling.
• Millions of J&J vaccines are due to expire this month.

The US government is stopping orders of Johnson & Johnson COVID-19 vaccines so states can try to use up stockpiled doses as vaccination rates drop, the Wall Street Journal reported on Thursday.

US state and federal health officials told The Journal that the Centers for Disease Control and Prevention (CDC) is banning states from ordering the J&J shot. Some of the officials said it was only a temporary measure.

Michigan, Oklahoma, and Illinois haven't been able to order new supplies of the one-dose vaccine in recent weeks, according to health officials there. Some said their state had enough doses of the shot.

"It just hasn't been included in our weekly allocations, from the feds, which means it is not available to order," Keith Reed, deputy commissioner of Oklahoma's state department of health, told the Journal.

It was unclear exactly why the government halted the J&J vaccine shipments based on the comments from officials, the Journal reported.

The vaccine suspension comes after the Food and Drug Administration (FDA) on Thursday extended the shelf life of the J&J vaccine from three months to four-and-a-half months when refrigerated.

States currently have excess doses of the J&J vaccine, and millions of the single-dose vaccines are set to expire in June. The J&J shot was authorized by the FDA in February.

J&J told Insider it would "continue to work with the US government and health authorities to support the use of our vaccine, which continues to play an important role, including among those who wish to be fully vaccinated with one shot."

Just over half of the American adult population have received at least one dose of a COVID-19 shot, according to data from the CDC.

But vaccine uptake is dropping. On April 1, vaccination rates hit a peak of 4.3 million, but in June that number fell to an average of less than one million a day, CDC data showed.