More than 82 million COVID-19 vaccine doses have reportedly gone to waste since the beginning of the pandemic, according to media reports. 

The Centers for Disease Control and Prevention (CDC) shared the data with NBC News, meaning that just over 11% of doses the federal government distributed between December 202 through mid-May were discarded. 

That’s nearly 20 million more doses wasted than the 65 million The Associated Press reported wasted in February. 

Two retail pharmacy chains, CVS and Walmart, were responsible for over a quarter of the doses thrown away in the United States in that time period, in part due to the sheer volume of vaccine they handled.

Five other pharmacies or dialysis centers: Health Mart, DaVita, Rite Aid, Publix and Costco, wasted fewer overall doses, but a higher share: more than a quarter of the vaccine doses they received, well above the national average. Two states also discarded more than a quarter of their doses: Oklahoma, which tossed 28 percent of the nearly 4 million doses it received, and Alaska, which threw away almost 27 percent of its 1 million doses, according to the CDC data.

The overall amount of waste is in line with World Health Organization estimates for large vaccination campaigns. But public health experts said the waste is still alarming at a time when less than half of fully vaccinated Americans have a booster shot — which is critical to fight newer, more contagious virus strains — and when many poorer countries continue to struggle with vaccine supply.

“It’s a tremendous loss to pandemic control — especially in the context of millions of people around the world who haven’t even been able to get a first dose,” said Dr. Sheela Shenoi, an infectious disease expert at the Yale School of Medicine.

The millions of wasted vaccine doses include some that expired on pharmacy shelves before they could be used, others that were spoiled by the thousands when power went out or freezers broke, and still others that were tossed at the end of the day when no one wanted the last few doses in an opened vial.