CNN – Americans are at odds over whether it's necessary to keep taking coronavirus protective measures, but a leading researcher says the data is clear: The path ahead in the Covid-19 pandemic is being shaped by masks.
"We now have really clear evidence that wearing masks works -- it's probably a 50% protection against transmission," Dr. Chris Murray, director of the Institute for Health Metrics and Evaluation, or IHME, at the University of Washington, told CNN late Tuesday.
"And so, what happens in the next month or two is very much in the hands of how people respond."
But as health experts stress the importance of wearing masks, the matter has gotten political. President Donald Trump has foregone face coverings in public while his presumptive rival Joe Biden has worn one, staking their ground in the partisan debate over whether masks are a paranoid restriction or a necessary precaution.
At least 1,681,418 people in the US have been infected with the virus through Wednesday and 98,929 people have died, according to Johns Hopkins University.
The number of US deaths forecast by August has shifted to 132,000 -- 11,000 fewer than projected a week ago -- according to the IHME's model, one of more than a dozen highlighted by the US Centers for Disease Control and Prevention.
Behavioral changes like wearing masks could be responsible for the reduction, Murray said.
Many officials have urged their residents to wear masks. Former acting CDC director Dr. Richard Besser called it "an American thing to do," and Ohio Gov. Mike DeWine said wearing a mask isn't political, it's "about loving your fellow human being."
Still, warmer weather and a holiday weekend drew large crowds from their homes and into public spaces recently, with many faces uncovered.
The decision to wear a mask or avoid one will determine what happens next in the pandemic, Murray said.
Tests could be wrong and danger could be higher
Many reopenings also are contingent on testing and data showing that the transmission of the virus is low. But the accuracy of some tests has been called into question.
Antibody tests used to determine if people have been infected in the past with Covid-19 might be wrong up to half the time, the US Centers for Disease Control and Prevention said in new guidance posted on its website.
Health care providers might need to test people twice, the CDC said. The tests that look for evidence of an immune response to infection are not accurate enough to make policy decisions.
There are also implications for individual decision making. Although there is little evidence yet to show that having recovered from the virus provides immunity from contracting Covid-19 again, health experts worry that a test that falsely shows the presence of antibodies would influence people to behave as if they had the infection and are now protected.
And the numbers may even be confounded by tests for current illness.
Doctors are increasingly reporting that they cannot find evidence of the virus until they perform tests deep in the respiratory system. Many children have come into hospitals severely ill but do not test positive until after repeated tests.
It is not only a problem for treating patients -- it calls into question whether low reports in cases really means it is time to reopen workplaces and public spaces.
How the infection numbers are trending
Infection rates vary from state to state.
Illinois appears to be entering a "downward trend," with the week ending May 16 being the first with a lower number of coronavirus deaths than the week before, Illinois Public Health Director Dr. Ngozi Ezike announced at a news conference Tuesday.
But the possible trend is still at its early stages, Ezike said, and the public has a responsibility to continue to decrease transmission.
New York, the hardest hit state for the virus, reported Monday that 73 residents died in a single day, the lowest daily death toll since the start of the pandemic in the US, Gov. Andrew Cuomo said Tuesday.
But other regions do not have the same good news. There were 17 states as of Tuesday in which the number of cases was still trending upward.
Mississippi Gov. Tate Reeves warned residents to stay vigilant in a news conference Tuesday because the state is still seeing a steady number of cases.
Meanwhile, Michigan Gov. Gretchen Whitmer said, despite pressure from the public and a decline in cases, the state is also not letting its guard down.
"Now, I'm not going to be bullied into ignoring the science and making political calculations," Whitmer said. "Let's not, us here in Michigan, have made this sacrifice in vain, and see our numbers start to rise again. ... That means masks and distancing, and hand washing."
Elsewhere, Washington DC, is on track to report 14 days of coronavirus decline Wednesday, a benchmark that has been cited for a safe reopening.
Steady numbers spark reopenings
Every state has begun to reopen, lifting restrictions on businesses and public spaces often in phases specific to the needs of the area.
"We are walking into the unknown," California Gov. Gavin Newsom said. The state was one of the first to impose restrictions and has been on the back end of lifting them.
More than 80% of counties in the state are allowed to begin the third of a four-phase reopening plan. This stage includes allowing hair salons and barbershops to reopen along with retail shops.
The state has reported 99,810 cases and 3,826 deaths, but hospitalizations have been declining slightly over the past two weeks, and the number of those in ICU beds remains stable, the governor said.
The state's final phase of reopening includes resumption of concerts and spectator events, but Newsom says, "we are not there yet."
Such large gatherings could soon resume in Florida, where Walt Disney World and Sea World on Wednesday will present reopening plans to the Orange County Economic Recovery Task Force, according to a county news release.
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