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Final Coronavirus Vaccine Trials Get Underway

TUESDAY, July 28, 2020 (HealthDay News) -- As the U.S. coronavirus case count passed 4.3 million on Monday, companies launched the final phase of testing for two potential COVID-19 vaccines.

In one trial begun on Monday, the first of 30,000 volunteers were either given a vaccine developed by Moderna Inc. and the U.S. National Institutes of Health or a placebo shot, the Washington Post reported.

Pharmaceutical giant Pfizer also announced Monday that it was starting a 30,000-person final phase vaccine trial, to be conducted at 120 sites globally.

"We are participating today in the launching of a truly historic event in the history of vaccinology," Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said during a news conference on the Moderna vaccine, the Post reported.

He predicted that researchers would probably be able to tell whether the Moderna vaccine was effective by November or December, although he added that it was a "distinct possibility" an answer could come sooner. Pfizer officials have said the company expects to be able to seek regulatory authorization or approval for its vaccine by October, the Post reported.

Both vaccines require two doses, spaced several weeks apart. Then researchers will have to wait to see whether people get infected or sick with COVID-19. A clear signal of success or failure will depend on how fast the trials recruit participants and how long it takes for enough people to become infected to observe whether there is an effect, the Post reported.

To show the Moderna vaccine is 60 percent effective, Fauci said, there would need to be about 150 infections among the 30,000 participants.

In terms of slowing the spread of coronavirus, there were new signs of hope on Monday. New cases numbers leveled off in Florida, Texas and Arizona, The New York Times reported.

Texas, which joined California, New York and Florida on Monday to become the fourth state with more than 400,000 known cases, has seen the seven-day average of new cases drop from a high of 10,461 on July 19 to 8,243 on July 26. Florida's seven-day average of new cases hit a high of 11,870 on July 17 and fell to 10,544 on July 26, the Times reported. In Arizona, the seven-day average of new cases is also down, from 3,849 on July 6 to 2,628 on July 26.

Testing delays bedevil efforts to curb spread

Still, laboratories across the country are being crushed by the surge of COVID-19 tests, the Associated Press reported.

The bottlenecks are creating problems for workers kept off the job while awaiting results, nursing homes struggling to keep the virus out, and for the labs themselves, the wire service said. Some labs are taking weeks to return COVID-19 results, fueling fears that people without symptoms could be spreading the virus if they don't isolate while they wait.

"There's been this obsession with, 'How many tests are we doing per day?'" former CDC Director Dr. Tom Frieden told the AP. "The question is how many tests are being done with results coming back within a day, where the individual tested is promptly isolated and their contacts are promptly warned."

Frieden and other public health experts have called on states to publicly report testing turnaround times, calling it an essential metric to measure progress against the virus.

In an effort to find a faster and cheaper way of testing Americans, the U.S. Food and Drug Administration has given emergency approval to pooled testing, which combines test samples in batches, the AP reported.

With pooling, laboratories would combine parts of samples from several people and test them together. A negative result would clear everyone in the batch. A positive result would require each sample to be retested.

The technique works best when fewer than 10% of people are expected to test positive, the AP reported. For example, pooling would not be cost-effective in Arizona, where a surge has pushed positive test results to well over 10%.

By Tuesday, the U.S. coronavirus case count passed 4.3 million as the death toll passed 148,400, according to a Times tally.

According to the same tally, the top five states in coronavirus cases as of Tuesday were: California with over 467,000; Florida with nearly 432,700; New York with over 417,000, Texas with over 402,000 and New Jersey with nearly 182,000.

Nations grapple with pandemic

Elsewhere in the world, the situation remains challenging.

In Hong Kong, officials said Monday they will ban public gatherings of more than two people, suspend all inside dining and mandate masks in public places including the outdoors, the strictest measures issued against COVID-19 since the virus began spreading widely in January, the Post reported.

Chief Secretary for Administration Matthew Cheung, said the measures will take effect Wednesday and continue for seven days before they are reviewed again.

Vietnam is evacuating 80,000 people from the central city of Danang after four residents tested positive this weekend. The country had gone 100 days without a single case of local transmission, the Times reported.

The evacuation is expected to take at least four days. The evacuees are mostly local tourists; Vietnam remains closed to incoming foreign tourists, the Times reported.

Things continue to worsen in India. On Tuesday, the country neared 1.5 million infections and over 33,400 deaths, a Johns Hopkins tally showed. The surge comes weeks after a national lockdown was lifted, and it's prompted some parts of the country to revert back to stricter social distancing measures. Only the United States and Brazil have higher caseloads.

Brazil is also a hotspot in the coronavirus pandemic, with more than 2.4 million confirmed infections by Tuesday, according to the Hopkins tally. It has the second-highest number of cases, behind only the United States.

Cases are also spiking wildly in Russia: As of Tuesday, that country reported the world's fourth-highest number of COVID-19 cases, at over 822,000, the Hopkins tally showed.

Worldwide, the number of reported infections passed 16.4 million on Tuesday, with more than 654,000 deaths, according to the Hopkins tally.

More information

The U.S. Centers for Disease Control and Prevention has more on the new coronavirus.

SOURCES: The New York Times; Washington Post; Associated Press

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