People wearing face masks are seen on an airport express train in Seattle, the United States, March 14, 2021. (Xinhua/Wu Xiaoling)
Public health experts are concerned that the United States may witness a COVID-19 resurgence if states and people do not cautiously follow safety and protective measures.
More than a dozen states have seen an uptick in COVID-19 infections, including Alaska, Connecticut, Delaware, Idaho, Maine, and Nevada, according to the latest data of the U.S. Centers for Disease Control and Prevention (CDC).
Although the country's national daily case average continues to fall -- about 32.5 percent over the last month -- nearly a third of all states have seen their average number of cases rise at least 10 percent, according to an ABC News report.
Several states, including Delaware, Idaho, Minnesota, Nevada, Oregon and West Virginia, have seen their case averages increase by at least 25 percent in the last week.
"I don't expect to see something as bad as we just recovered from, but if we're not careful, cases can rise again if we let our guard down too soon," said Tara Smith, a professor of epidemiology at the Kent State University College of Public Health.
Health officials have repeatedly warned about a potential COVID-19 resurgence as some state leaders have lifted mask mandates and eased restrictions.
It is too early to know if the drop in new cases is a turning point "because new, more contagious variants are circulating in the country," Stanley Perlman, professor of microbiology and immunology at the University of Iowa, told Xinhua in a recent interview.
Experts are concerned that new variants are outpacing the vaccinations, and have called on the public to double down on safety measures such as wearing face masks, social distancing and avoiding crowded areas.
A total of 4,855 infection cases of coronavirus variants had been reported in the United States as of Tuesday, according to CDC data.
The vast majority of these cases, 4,686, were caused by the variant known as B.1.1.7, which was originally detected in Britain.
There were 142 cases of a new strain initially discovered in South Africa, called B.1.351, and 27 cases of the P.1 strain first discovered in Brazil.
"We hope that the vaccine rollout will outweigh the variants spread," Perlman said.
