Global coronavirus cases exceeded 10 million on Sunday according to a Reuters tally, marking a major milestone in the spread of the respiratory disease that has so far killed almost half a million people in seven months.

Florida and four other states recorded daily highs for cases of COVID-19 on Saturday, highlighting the worsening spread of the coronavirus in parts of the U.S. South and West, prompting some officials to roll back their reopening plans.

The United States recorded 45,242 new cases of COVID-19 on Friday – the largest single-day increase of the pandemic – according to a Reuters tally, bringing the total number of Americans who have tested positive to at least 2.48 million.

The governor of Texas temporarily halted the state’s reopening as COVID-19 infections and hospitalizations surged and the country set a new record for a one-day increase in cases.

Government experts believe more than 20 million Americans could have contracted the coronavirus – 10 times more than official counts – indicating many people without symptoms have or have had the disease, senior administration officials said.

Many studies assessing the accuracy of COVID-19 antibody tests had major shortcomings, a review concluded, offering further evidence the blood tests are of little use for people seeking to know with certainty if they have been infected.

In the battle against COVID-19, the United States continues to see spikes in multiple states, and the nation’s top virus expert says the next few weeks will be critical to contain the spread of the disease that has caused the death of more than 121,000 Americans.

After more than 100 days of lockdown, New York City residents celebrated their progress in curbing the coronavirus pandemic by getting their first haircuts in months, shopping at long-closed stores and dining at outdoor cafes.

Global cases of the novel coronavirus surpassed 9 million as Brazil and India grappled with a surge in infections while the United States, China and other hard-hit countries reported new outbreaks, according to a Reuters tally.

The coronavirus pandemic is accelerating, with Thursday’s 150,000 new cases the highest in a single day and nearly half of those in the Americas, the World Health Organization (WHO) said.