WASHINGTON — Johnson & Johnson says U.S. health officials have extended the expiration date for its COVID-19 vaccine by six weeks.

The drugmaker said Thursday that the Food and Drug Administration approved a shelf life of four-and-a-half months for the one-dose shots.

The decision comes just days after the Wall Street Journal reported that millions of doses of the vaccine were set to expire in the coming weeks. Following that report, White House COVID-19 response team adviser Andy Slavitt said that regulators were looking at opportunities for "continued storage."

State officials recently warned that millions of doses would reach their original three-month expiration date by the end of June. The stockpile of doses developed earlier this year when the use of the drug was briefly paused while officials assessed reports of blood clotting.

The CDC and FDA both said the benefits of the vaccine outweighed the risk following an 11-day pause. However, that stoppage has left some states with more supply than demand.

Earlier this week, Ohio Gov. Mike DeWine said that his state has 200,000 doses of the J&J vaccine that are set to expire on June 23.

“The time to act is now,” DeWine said. “For Ohioans who have been waiting to get their vaccine, I urge you to take action now. There are many opportunities throughout the state to get a vaccine. The Johnson & Johnson vaccine is one of those options. It is safe and effective and only requires one shot. In just two weeks, you could be protected from this virus. Getting vaccinated is the quickest way out of the pandemic and the fastest way for us to return to the lives we remember.”

Vaccine expiration dates are based on information from drugmakers on how long the shots stay at the right strength. Regulators are reviewing those dates as companies have continued to test batches.

The extension comes as the number of U.S. vaccinations continues to slip. While 64% of Americans are fully vaccinated, Bloomberg reports that the number of daily vaccinations the U.S. has conducted has steadily dropped since mid-April.