US COVID-19 cases top 50 million

The total number of COVID-19 cases in the United States has surpassed 50 million on Monday, while the death toll from the disease is approaching 800,000, according to data from Johns Hopkins University.

The United States remains the country worst hit by the pandemic, with the world's most cases and deaths. The new Omicron variant has reached more than half of the U.S. states and the dominant Delta variant continues to run rampant around the nation.

Experts said the high caseload and death toll are the results of a confluence of factors: low vaccination rates, colder weather that forces more people indoors, and a still-divided political response to combatting the virus.

The rising COVID-19 cases are driven partly by the Delta and the Omicron variants which have been spreading rapidly across the United States.

The current seven-day daily average of COVID-19 cases is about 118,500, a 37-percent jump from the previous week, according to data from the U.S. Centers for Disease Control and Prevention (CDC).

The seven-day average of daily deaths is about 1,100, up 28 percent from the prior week, the CDC said.

Currently, the United States is witnessing about 7,400 new hospital admissions each day, a 16-percent increase from the previous week, the data showed.

The Omicron variant, which is possibly more contagious than the Delta variant, has been found in at least 29 U.S. states as of Monday, since the country's first confirmed case of the Omicron COVID-19 variant was identified in the state of California on Dec. 1.

The number reflected the potentially heightened transmissibility of the Omicron strain and complexity in taming the pandemic, health experts said.

Mutations in Omicron might increase transmissibility, confer resistance to therapeutics, or partially escape infection or vaccine-induced immunity, according to the CDC.

The United States had suffered a miserable winter, with 300,000 daily COVID-19 cases reported in early January this year.

The number and growth of daily cases, deaths, hospital admissions continued to set new records at the time. COVID-19 cases around the country have surged from 21.8 million in early January to over 50 million in December.

Carlos del Rio, executive associate dean of the Emory School of Medicine and Grady Health System in Georgia, told Xinhua that the main reasons for the recent surge were increasing the transmissibility of new variants, seasonality of the pandemic which sees the number of cases increasing in colder weather, and the number of the unvaccinated.

In most places in the country where key COVID-19 indicators are rising, cases, hospitalizations, and deaths are mostly among the unvaccinated, del Rio said in an email interview with Xinhua.

About 202.2 million Americans, or 60.9 percent of the population, have been fully vaccinated as of Sunday. About 54.4 million fully-vaccinated people have received a booster dose, according to CDC data.

Yet nearly 40 percent of the U.S. population has not been fully vaccinated.

CDC Director Rochelle Walensky said earlier that COVID-19 has become "a pandemic of the unvaccinated."

Del Rio said the United States may witness another difficult winter next year. "Getting more people vaccinated through mandates and requirements, providing boosting, and making rapid testing readily available are the priorities," he told Xinhua.