Johnson & Johnson said Thursday that U.S. regulators have extended the expiration date for millions of doses of its Covid-19 vaccine by a further six weeks.
The company said a Food and Drug Administration review concluded that the injections remained safe and effective for up to 4.5 months. The announcement comes after state officials warned that many unused doses in storage would expire before the end of the month.
Vaccine expiration dates are determined based on data the manufacturer submits to regulators proving how long the injections stay at the correct strength. The FDA initially cleared J & J’s vaccine for use up to 3 months after manufacture when stored at normal refrigeration levels. But J&J said the FDA had extended the period to 4.5 months, based on data from ongoing studies assessing the stability of the vaccine.
The FDA has reviewed the expiration dates for the three licensed vaccines as companies have continued to test batch samples in the months since the injections first started.
For comprehensive coverage of the coronavirus epidemic
The expansion will help maintain vaccine supplies even as the rate of new injections continues to decline. The country averaged about 800,000 new injections per day last week. That’s down from a high of almost 2 million a day two months ago. Government officials have turned to a growing number of incentives to encourage the shootings – paid vacations to million dollar lottery prizes.
As vaccinations have slowed, it has become clear that the United States is unlikely to meet President Joe Biden’s target of having 70% of American adults partially vaccinated by July 4. About 64% of Americans over 18 have received at least one dose, according to the Centers for Disease Control and Prevention.
J & J’s vaccine was highly anticipated due to its unique formulation and easy-to-ship refrigeration requirements. The vaccine was to play a key role in vaccination campaigns in rural areas and low-income countries with limited health care infrastructure.
But rival drugmakers Pfizer and Moderna have already supplied more than enough doses to meet U.S. demand, with more than 129 million Americans fully vaccinated with the companies’ two-dose injections. In comparison, only 11 million Americans have been vaccinated with the J&J vaccine.
The United States is expected to announce plans to donate 500 million doses of Pfizer vaccine for global use over the next year, in addition to the 80 million doses already pledged by the end of the month.
Adoption of J & J’s vaccine in the United States has also been affected by contamination issues at a Baltimore plant that helps manufacture the vaccines. The facility was closed after an FDA inspection revealed multiple problems in April and none of the vaccines made there were distributed.
Follow NBC HEALTH on Twitter & Facebook