Delta strain becomes dominant variant in U.S.

Visitors tour the National Mall in Washington, D.C., the United States, June 26, 2021. (Photo by Ting Shen/Xinhua)

The Delta variant represented 51.7 percent of new COVID-19 infections in the United States over the two weeks ending July 3, according to the CDC.

WASHINGTON, July 7 (Xinhua) -- The highly transmissible Delta strain has overtaken the Alpha variant to become the dominant variant in the United States, according to new estimates from the U.S. Centers for Disease Control and Prevention (CDC).

Delta, which was first found in India and is now in over 100 countries, represented 51.7 percent of new infections in the United States over the two weeks ending July 3, according to the CDC.

Meanwhile, the proportion of new cases caused by Alpha, which was first detected in Britain, was just 28.7 percent over the same time period, according to the CDC.

Recently, health officials and experts have warned that the Delta variant was on track to become the dominant variant in the United States, as its prevalence in the nation doubles about every two weeks.

They are concerned the variant will cause a surge in new cases this fall, hitting the unvaccinated population the hardest.

Increasing cases were reported in states with lower vaccination rates, including Alabama, Arkansas, Louisiana and Mississippi, according to the CDC.

People walk on street in New York, the United States, June 15, 2021. (Xinhua/Michael Nagle)

Although Delta is highly contagious, research show that most vaccines still remain highly effective at preventing hospitalizations and deaths caused by the variant.

U.S. President Joe Biden on Tuesday pushed for all eligible Americans to get COVID-19 vaccinations, stressing the importance of being protected against Delta.

The country reached its highest vaccination rate in mid-April when the seven-day average of doses administered daily topped about 3.4 million. But the rate has dropped since then.

About 47.6 percent of the U.S. population is fully vaccinated against COVID-19, and 55.1 percent of the population has received at least one shot as of Wednesday, CDC data show.

Biden set a goal in May of having 70 percent of American adults receive at least one COVID-19 shot by the Fourth of July. But just 18 states and Washington, D.C. surpassed that goal by the date, according to a Forbes report.