Following is a summary of current health news briefs.

COVID-19 forces some U.S. schools to close, as new cases remain high in most states

Almost as quickly as they welcomed students back, some U.S. schools are closing again due to outbreaks of COVID-19, the latest challenge as the nation tries to reopen while the level of new cases per day remains high in most states. Schools in the United States are set to reopen for the start of the academic year either this month or early September. Some – particularly in urban centers – have opted for online-only learning, while others have chosen in-person learning or a hybrid of the two.

U.S. COVID-19 deaths rise; cases drop for fourth week in a row

The U.S. death toll from COVID-19 rose 2% to about 7,400 people last week, while new cases declined for a fourth week in a row, according to a Reuters tally of state and county reports. The country posted 360,000 new COVID-19 cases for the week ended Aug. 16, down from a weekly peak of over 468,000 cases in mid-July. The United States has the worst outbreak in the world in terms of total cases and deaths, accounting for a quarter of the global total of 21 million cases.

What you need to know about the coronavirus right now

Here’s what you need to know about the coronavirus right now: Concern over U.S. autumn resurgence Immune response after mild COVID-19 is prolonged; psychiatric risk revealed

The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus. Mild COVID-19 induces prolonged immune response.

U.S. states seek $2.2 trillion from OxyContin maker Purdue Pharma: filings

U.S. states claimed they are owed $2.2 trillion to address harm from OxyContin maker Purdue Pharma LP’s alleged role in America’s opioid epidemic, accusing the drugmaker in new filings of pushing prescription painkillers on doctors and patients while playing down the risks of abuse and overdose. In filings made as part of Purdue’s bankruptcy proceedings that were disclosed on Monday, the states said Purdue, backed by the wealthy Sackler family, contributed to a public health crisis that has claimed the lives of roughly 450,000 people since 1999 and caused strains on healthcare and criminal justice systems. The filings cited more than 200,000 deaths in the U.S. tied directly to prescription opioids between 1999 and 2016.

Hispanics, non-white workers highly affected by U.S. COVID-19 outbreaks, says CDC

Outbreaks of the new coronavirus in U.S. workplaces have disproportionately hit Hispanic and non-white communities, according to an analysis of data from Utah by the Centers for Disease Control and Prevention. According to the report, workers from those communities accounted for 73% of workplace-associated COVID-19 cases between March 6 and June 5, even though only 24% of Utah’s workforce in all affected sectors identified as Hispanic, Latino, or a race other than non-Hispanic whites.

Testing of CanSino’s COVID-19 candidate vaccine begins in Russia

Russia’s Petrovax has started a late-stage trial of a COVID-19 candidate vaccine from CanSino Biologics Inc in the country, records show, as the Chinese drug firm steps up testing abroad to close in on regulatory approval. The Ad5-nCoV vaccine already has approval for use by China’s military after early and mid-stage trials, and further late-stage trials are being lined up for Mexico and Saudi Arabia.

U.S. CDC reports 169,350 deaths from coronavirus

The U.S. Centers for Disease Control and Prevention (CDC) on Monday said the number of deaths due to the new coronavirus had risen by 654 to 169,350 and reported 5,382,125 cases, an increase of 41,893 cases from its previous count. The CDC reported its tally of cases of the respiratory illness known as COVID-19, caused by a new coronavirus, as of 4 pm ET on August 16 versus its previous report released on Sunday. (https://bit.ly/2DT7ymp)

U.S. court upholds patent for Novartis MS drug Gilenya

A U.S. district court upheld the validity of a patent for Swiss drugmaker Novartis’ top-selling multiple sclerosis (MS) drug Gilenya, helping Novartis protect its blockbuster MS treatment from U.S. competition. The U.S. District Court for the district of Delaware said in a ruling dated Aug. 10 and unsealed on Monday that Novartis’ patent was valid, rejecting a lawsuit from generic maker HEC that was backed by other generic drugmakers.

Mink at two Utah farms test positive for COVID-19

The United States Department of Agriculture (USDA) said on Monday that mink at two farms in Utah tested positive for the novel coronavirus, the first such confirmed cases in the animal in the country. People who had contact with the animals have also tested positive for the virus, which causes COVID-19 in humans, the agency said. (https://bit.ly/3aykgCI)