A Massachusetts Veterans Affairs hospital said that nearly 2,000 doses of Moderna's Covid-19 vaccine were spoiled after a cleaning contractor accidentally unplugged a refrigerator.
The 1,900 doses were located at a VA facility in the Boston neighborhood of Jamaica Plain, where on Tuesday VA officials realized that the doses had not been stored at proper temperatures, NBC News Boston reported.
A VA spokesperson told the NBC News affiliate that a contractor "accidentally removed [an electrical plug] while cleaning" and that an investigation is underway to find out why the freezer's alarm system and monitoring system did not work as intended.
The VA also said that replenishments were on the way and that they did not expect that the loss of nearly 2,000 doses of vaccine would impact their vaccination efforts.
According to a count by NBC News, Massachusetts has confirmed 486,180 Covid-19 cases since the start of the pandemic last year.
The Boston Public Health Commission declined to comment and directed inquiries to the VA Medical Center.
The Department of Veterans Affairs and Boston VA did not immediately respond to a NBC News request for comment.
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Both Moderna and Pfizer-BioNTech's vaccines require specific sub-freezing temperature ranges for storage, meaning that supply chains must be able to provide long-term temperature-controlled transit.
While nearly 2,000 Moderna doses were ruined in Tuesday's VA incident by warm temperatures, nearly 12,000 were spoiled earlier this month because temperatures were too cold during transit.