Unused COVID-19 vaccines are piling up in several US states, including West Virginia, Wisconsin, and New Jersey, Bloomberg News reports, referring to its vaccine tracker.
It showed the percentage of delivered doses that have been used in some states based on data released by the US Centres for Disease Control and Prevention (CDC).
According to Bloomberg News, "the worst-performing quartile of states holds 14.1 million unused doses, meaning that 31% of doses delivered in those states are yet to be marked as used".
In West Virginia, for example, about 26% of doses remain unused despite the state earlier being praised for the rollout of shots.
In contrast, the best-performing quartile of states sees just 11% of doses unused, the tracker showed.
The report about unused vaccines comes after Andy Slavitt, senior adviser for the White House's COVID Response team, said that Washington aims to vaccinate more people in the upcoming weeks.
"We're going to go through stages, as we vaccinate higher and higher portions of populations, where it will make sense for us to continue to watch where vaccines are needed, how vaccines are distributed, the best way to reach more people", Slavitt stressed.
The nation's federal health authority has, meanwhile, recommended a "pause" in the use of Johnson & Johnson's single-dose COVID-19 vaccine due to the drug's purported side effects.
Peter Marks, director of the US Food and Drug Administration's Centre for Biologics Evaluation and Research, told reporters that one patient had died and another one remains in critical condition due to blood clots after receiving Johnson & Johnson's COVID-19 vaccine.
A Johnson & Johnson spokesperson, in turn, said the company was collaborating with regulators, and supported "open communication" with healthcare providers regarding any new findings, so that any related risks might be monitored.