Covid-19 Live Updates: New York Goes a Month With a Positivity Rate of Under 1 Percent

‘Be smart’: New Yorkers get good news on virus numbers, but also a warning.

The share of virus tests coming back positive in New York State has stayed below 1 percent for 30 straight days, suggesting that the state’s aggressive approach to containing its outbreak — once the most severe in the country — has largely worked.

The state’s positivity rate, announced on Sunday, remained below 1 percent even as parts of the economy gradually reopened, the number of people being tested continued to trend upward, and other states grappled with sharply rising case counts.

But for all the encouragement offered by the monthlong marker, many New Yorkers remain anxious heading into the fall and winter, when case counts could rise as the nation’s largest public school district and more businesses are preparing to reopen.

Even Gov. Andrew M. Cuomo, in announcing the figure, took the opportunity to urge not celebration but continued restraint, pointing in a statement to New York’s approach to reopening — slower and more controlled than in most other states — as well as its statewide mask mandate.

Ms. Harris’s remarks came after federal officials alerted state and major city public health agencies last week to prepare to distribute a vaccine to health care workers and other high-risk groups as soon as late October or early November. Given that no vaccine candidates have completed the kind of large-scale human trials that can prove efficacy and safety, that time frame has heightened concerns that the Trump administration is seeking to rush a vaccine rollout ahead of Election Day, Nov. 3.

For months, Ms. Harris and Joseph R. Biden Jr. have assailed Mr. Trump for his handling of the coronavirus crisis. Ms. Harris’s comments on Sunday questioning a potential vaccine, as scientists racing for a vaccine report constant pressure from a White House anxious for good news, are likely to further sow skepticism among Americans considering whether to get the vaccine when it becomes available.

With concern about the politicization of vaccines and treatments on the rise, five drug companies are preparing to issue a statement this week pledging to not release a vaccine unless it meets rigorous standards for effectiveness and safety. The companies — Pfizer, Moderna, Johnson & Johnson, GlaxoSmithKline and Sanofi — are aiming to reassure the public that they will not seek premature approval under political pressure.

Ms. Harris on Sunday also said she and Mr. Biden would set a national “standard” for mask wearing, stopping short of endorsing a mandate.

“This is not about punishment. It’s not about Big Brother,” Ms. Harris said, adding that wearing a mask is a “sacrifice” in a time of crisis.

Her comments appeared to be a softening of the position she and Mr. Biden have previously staked out.

Last month, Mr. Biden and Ms. Harris called for Americans to be required to wear masks, telling reporters after receiving a briefing from public health experts that every American should wear a mask while outside for at least the next three months and that all governors should mandate mask wearing.

“We are open to thinking outside the box and coming up with new ways to handle this pandemic,” said Esther Babady, the director of the clinical microbiology service at Memorial Sloan Kettering Cancer Center in New York. But she said antigen tests that could work at home had yet to enter the market.

Also, no rigorous study has shown that fast and frequent testing is better than sensitive but slower in the real world, she said. “The data for that is what’s missing.”

What has been put forth about the approach is “largely aspirational, and we need to check it against reality,” said Dr. Alexander McAdam, the director of the infectious diseases diagnostic laboratory at Boston Children’s Hospital and an author of a recent report on pandemic testing strategies in The Journal of Clinical Microbiology.

Most of the virus tests to date rely on a laboratory technique called PCR, long considered the gold standard because it can pick up even small amounts of genetic material from germs like the coronavirus.

But sputtering supply chains have compromised efforts to collect, ship and process samples for PCR tests, lengthening turnaround times. And the longer the wait, the less useful the result.

Last Monday, the University of Washington, based in Seattle, sent an email to about 500 of its researchers telling them to be wary of suspicious packages and saying that virus researchers elsewhere had been targeted.

“We have received unfortunate reports from our contacts at the Federal Bureau of Investigations (FBI) that threatening mail has been sent to COVID-19 researchers on the east coast of the United States,” said the email, which was first reported by BuzzFeed News on Saturday.

The BuzzFeed News article quoted an F.B.I. spokesman saying that the bureau, “along with our local law enforcement partners, responded to a suspicious package sent to a few university researchers” and that “preliminary testing has indicated there is no threat to public safety in connection with this mailing.”

A University of Washington spokeswoman, Susan Gregg, provided a copy of the university’s email to The New York Times and said no suspicious packages had been reported so far.

The email warned researchers to be on the lookout for signs of suspicious mail, including an address with misspelled words, no return address, oily stains, discoloration or a strange odor. Any mail that raised concerns, the email said, should be left unopened and reported to the police by calling 911.

Research at the University of Washington includes 16 clinical studies related to the virus and a prominent but sometimes criticized forecasting model. The model estimated last week that Covid-19 would kill about 410,000 people in the United States by the end of the year, more than double the current death toll, drawing skepticism from experts who said predictions about the course of the pandemic months into the future are too uncertain to be useful.

The report of threats to researchers follows earlier signs of the risks faced by public health officials and others involved in the pandemic response. Dr. Anthony Fauci, a member of President Trump’s virus task force and the nation’s leading expert on infectious diseases, received additional security in April after threats, and he said the security was also expanded to his daughters. Local and state health officials have also been targeted by those challenging public health measures.

After earlier post-holiday spikes in cases, a warning for Labor Day weekend.

For many Americans, Labor Day is a goodbye to summer before children go back to school and cold weather arrives. But public health experts worry that in the midst of a pandemic, this weekend could result in disaster in the fall.

After the Memorial Day and Fourth of July weekends, cases of Covid-19 surged around the United States after people held family gatherings or congregated in large groups.

Dr. Anthony S. Fauci, the country’s top infectious disease expert, said he wanted people to enjoy Labor Day weekend, but urged precautions.

“You don’t want to tell people on a holiday weekend that even outdoors is bad — they will get completely discouraged,” Dr. Fauci said. “What we try to say is enjoy outdoors, but you can do it with safe spacing. You can be on a beach, and you don’t have to be falling all over each other. You can be six, seven, eight, nine or 10 feet apart. You can go on a hike. You can go on a run. You can go on a picnic with a few people. You don’t have to be in a crowd with 30, 40 or 50 people all breathing on each other.”

In terms of daily case counts, the United States is in worse shape going into Labor Day weekend than it was for Memorial Day weekend. The nation now averages about 40,000 new confirmed cases per day, up from about 22,000 per day ahead of Memorial Day weekend.

When Mr. López Obrador was still kissing babies at rallies and comparing the virus to the flu, Ms. Sheinbaum was planning for a long pandemic. She pushed an aggressive testing and contact tracing campaign, and set up testing kiosks where people get swabbed for free.

She also required that everyone in Mexico City use face coverings on public transit, and wore a mask each time she addressed the news media. And when doctors told her the N95 masks the federal government had imported from China were too narrow to fit Mexican faces, she had a local factory converted into a mask-making operation.

For Ms. Sheinbaum, a scientist with a Ph.D. in energy engineering, aligning too closely with the president would mean ignoring the practices she knows are in the best interest of public health. Stray too far, and she risks losing the support of a political kingmaker who is said to be considering her — the first woman and first Jewish person elected to lead the nation’s capital — as the party’s next presidential candidate.

So far, her strategy has been to follow the science while refusing to criticize the president.

Other coronavirus news from around the world:

The virus is spiking around college campuses as students return.

Within days of the University of Iowa’s reopening, students were complaining that they couldn’t get coronavirus tests or were bumping into people who were supposed to be in isolation. Undergraduates were jamming sidewalks and downtown bars, masks hanging below their chins, never mind the city’s mask mandate.

Now, Iowa City is a full-blown pandemic hot spot — one of about 100 college communities around the United States where infections have spiked in recent weeks as students have returned for the fall semester. Although the rate of infection has bent downward in the Northeast, where the virus first peaked in the United States, it remains high across many states in the Midwest and the South, and evidence suggests that students returning to big campuses are a major factor.

In a New York Times review of 203 U.S. counties where students make up at least 10 percent of the population, about half have experienced their worst weeks of the pandemic since Aug. 1. In about half of those, figures showed that the number of new infections is currently peaking.

Despite the surge in cases, there has been no uptick in deaths in college communities, data shows. This suggests that most of the infections are stemming from campuses, since young people who contract the virus are far less likely to die than older people.

However, leaders fear that young people who are infected will contribute to the spread of the virus throughout the community.

The surge in infections reported by county health departments comes as many college administrations are also disclosing clusters on their campuses, and taking disciplinary actions against students who flout rules. Northeastern University dismissed 11 students for violations last week, keeping their tuition.

And on Saturday, New York University said it had suspended 20 students since classes resumed. The virus’s potential spread beyond campus greens has deeply affected the workplaces, schools, governments and other institutions of local communities.

The result is often an exacerbation of traditional town-and-gown tensions as college towns have tried to balance economic dependence on universities with visceral public health fears.

Chance office encounters that used to allow for networking have been replaced by the formal geometry of the Zoom screen. And with fewer and less extensive connections than white colleagues to begin with, Black and Hispanic workers can find themselves more isolated than ever.

Assignments end up flowing to people who look more like top managers — a longstanding issue — while workers of color hesitate to raise their voices during online meetings, said Sara Prince, a partner at the consulting firm McKinsey.

“It’s a critical issue, and there is a real risk facing diversity and inclusion in the current environment,” Ms. Prince said. “When the leader is looking for someone to take up the mantle, most of them go to the comfort zone of people who remind them of themselves. This is exacerbated by the virtual office.”

It’s harder to tell which employees have shrunk back in their chairs or otherwise withdrawn in virtual meetings, said Evelyn Carter, managing director at Paradigm, a consulting firm, but moderators should pay attention to clues, like people with their cameras off, and try to draw those participants back into the discussion.

Some experts do see upsides for office workers who might have been marginalized.

“Most minorities are left out of informal networks and might not have been invited out for drinks or lunch,” said Tina Shah Paikeday, who oversees global diversity and inclusion advisory services at Russell Reynolds, a recruiting firm.

“The Zoom meeting is intentionally planned, and managers feel very intentional about inviting everyone.”

“It’s a great equalizer, and it creates opportunities for affinity group within large organizations,” she said. “It could end up being a good thing for minorities.”

Reporting was contributed by Kenneth Chang, Catie Edmondson, Natasha Frost, Robert Gebeloff, Shawn Hubler, Danielle Ivory, Jennifer Jett, Natalie Kitroeff, Sarah Kliff, Patrick J. Lyons, Tiffany May, Dera Menra Sijabat, Eric Nagourney, Richard C. Paddock, Tara Parker-Pope, Austin Ramzy, Nelson D. Schwartz, Mike Seely, Sarah Watson, Katherine J. Wu and Mihir Zaveri.