WASHINGTON, July 23 (Xinhua) -- COVID-19 cases, deaths and hospitalizations continue to surge among the unvaccinated across the United States, fueled by the rapid spread of the highly transmissible Delta variant.

More than 91 million people live in a county considered to have high COVID-19 transmission, according to the U.S. Centers for Disease Control and Prevention (CDC). And 48 states have a seven-day average of new cases at least 10 percent higher than the week before, according to data from Johns Hopkins University.

COVID-19 cases, hospitalizations and deaths were all up double digits in recent weeks as Delta spreads across the United States.

Currently, about 40 percent of new COVID-19 cases came from Florida, Texas and Missouri, according to the White House. Florida takes the lead in new coronavirus infections, and state hospitals have reported record number of COVID-19 patients.

Health experts blame the recent surges in COVID-19 cases on the low vaccination rates and the accelerating Delta variant transmission.

Los Angeles County officials said about 98 percent of those hospitalized in the last six months were unvaccinated people, adding Delta is a "game changer" as cases now rise among the vaccinated.

On Wednesday, the county reported a 20-fold increase in new cases over the previous month, according to the public health department.

About 48.8 percent of the U.S. population is fully vaccinated against COVID-19, and 56.4 percent of the population has received at least one shot as of Thursday, according to CDC data.

Slow vaccinations across the United States have ignited debate over mandated mask wearing and vaccinations.

Experts said with the highly contagious Delta variant spreading, particularly among unvaccinated Americans, it may be time for much of the country to put masks back on.

Los Angeles County reinstated a mask mandate last weekend, requiring masking indoors regardless of vaccination status. U.S. Surgeon General Vivek Murthy said other areas may have to follow.

"In areas where there are low numbers of vaccinated people, or where cases are rising, it's very reasonable for counties to take more mitigation measures like the mask rules you see coming out in LA, and I anticipate that will happen in other parts of the country," Murthy told ABC.