A version of this story appeared in the June 10 edition of CNN’s Coronavirus: Fact vs. Fiction newsletter. Sign up here to receive the need-to-know headlines every weekday.

CNN  — 

The World Health Organization has flip-flopped. And it’s not the first time.

An official at WHO yesterday rowed back an earlier comment that transmission of Covid-19 by people without symptoms is “very rare,” clarifying that asymptomatic spread is actually a “major unknown.”

Maria Van Kerkhove, WHO’s technical lead for coronavirus response, called it a “misunderstanding.” The agency’s bottom line: Someone with no symptoms can spread it.

The episode attracted widespread criticism over the organization’s public health messaging, and sparked scientific debate over the open question around asymptomatic spread.

The backpedaling highlighted the difficulties of communicating medical advice amid a rapidly changing pandemic, and to an audience desperate for good news.

“Worth keeping in mind that WHO staff … have been running at top speed since early Jan. Doing daily press briefings & assisting countries while under fire from all corners,” Devi Sridhar, a global public health expert at University of Edinburgh, said in a tweet. “They must be exhausted like all of us & need some support.”

But critics — that point to WHO’s delay in endorsing masks and previous insistence that small airborne droplets aren’t a big factor in the virus’ spread — say it’s not the first time the international body has diverged with global scientific consensus, and then changed course.

YOU ASKED. WE ANSWERED

Q: What’s the difference between asymptomatic and pre-symptomatic spread? And does it matter with coronavirus?

A: The WHO’s initial comments on Monday appeared to directly contradict guidance from public health organizations, including the US Centers for Disease Control and Prevention, which have said about a third of coronavirus infections may be asymptomatic. The CDC also estimates that 40% of coronavirus transmission is occurring before people feel sick, meaning they are pre-symptomatic. Here’s what you need to know:

Asymptomatic spread is the transmission of the virus by people who do not have symptoms and will never get symptoms from their infection. But those infected carriers could still get others very sick.

Pre-symptomatic spread is the transmission of the virus by people who don’t look or feel sick, but will eventually get symptoms later.

Send your questions here. Are you a health care worker fighting Covid-19? Message us on WhatsApp about the challenges you’re facing: +1 347-322-0415.

WHAT’S IMPORTANT TODAY

Exclusive: Kremlin spokesperson speaks out on Russia’s handling of the virus

Russia has been one of the countries hardest hit by the pandemic and the government’s response has received heavy criticism at home and abroad. Russian doctors have described critical shortages of equipment, (which hospital administrators and local governments deny), and observers have questioned whether Russia is under-reporting mortality figures.

But Kremlin spokesman Dmitry Peskov — who is back at work after being hospitalized with Covid-19 himself — has defended his country’s coronavirus response, in an exclusive interview with CNN.

Fauci says virus is “worst nightmare”

Dr. Anthony Fauci, the top US infection disease expert, has offered a bleak assessment of the coronavirus, describing the disease as his “worst nightmare” — in some ways more than Ebola or HIV.

“In a period of four months, it has devastated the world,” Dr. Fauci said during a conference held by the Biotechnology Innovation Organization. “And it isn’t over yet.”

19 states see rising cases with one asking hospitals to activate emergency plans

As parts of America have rushed to reopen without robust testing and contact tracing in place, health experts have warned that a second peak of Covid-19 is inevitable. Now, a spike in infections in 19 US states, believed to be linked to crowded Memorial Day celebrations, are raising concerns of just that. Arizona is already telling its hospitals to activate emergency plans in preparation for a surge in patients.

And some of those states that are seeing an upward trend are not following CDC guidelines on reporting probable cases.

After outbreak on US Navy carrier, many sailors have antibodies

An investigation of a major outbreak aboard the USS Theodore Roosevelt aircraft carrier may reveal clues as to how Covid-19 affects younger adults.

More than 1,000 of the ship’s nearly 4,900-member crew tested positive for coronavirus. After spending weeks at a port in Guam, the ship returned to sea last month. The majority — nearly 60% — of sailors in the study who had antibodies had neutralizing ones. These antibodies bind to the virus, potentially disabling it from attacking human cells. This is “a promising indicator of at least short-term immunity,” the researchers wrote.

ON OUR RADAR

  • Dice were flying and restaurants were jam-packed as Sin City reopened. The bad news: From casino floors and the busy sidewalks lining Las Vegas Boulevard, few visitors were wearing face coverings or practicing social distancing.
  • Parts of America were already struggling with access to groceries pre-pandemic. Now these areas, commonly known as food deserts, are even more problematic.
  • People “will and should have sex,” the New York City Health Department has said, encouraging people to “be creative” in its updated guidelines for safer sex during the pandemic.
  • Japanese tech conglomerate SoftBank says it’s conducted voluntary antibody tests on more than 44,000 employees, their families, clients and outside medical professionals such as doctors and dentists. That’s more than any other company in Japan.
  • The State Department informed Congress it intends to reopen the US consulate in Wuhan — where the coronavirus outbreak originated — later this month, according to a congressional notification obtained by CNN.
  • The global economy will take at least two years to recover from the impact of coronavirus, according to the Organisation for Economic Co-operation and Development (OECD), which is formed of 37 nations.

TOP TIPS

Imagine taking a walk in your neighborhood, carefully staying 6 feet apart from others to ensure social distancing. You see an elderly man collapse on the sidewalk. He’s having a heart attack. Everything you’ve heard of late tells you to avoid close contact with strangers, especially the elderly.

Is it safe to perform CPR (cardiopulmonary resuscitation) to try to save his life? There’s an answer: It’s strongly encouraged that people perform CPR or chest compressions on others during the global pandemic, according to a new report. In fact, you may actually be hundreds of times more likely to save the dying man’s life than you yourself are to die from Covid-19 by coming to his aid.

TODAY’S PODCAST

“There are several cases and participants who describe this ongoing fatigue and malaise, a feeling of not well.” Dr. Reynold Panetierri, a pulmonary critical care physician

Shortness of breath, fatigue, brain fog. Most Covid-19 patients recover from the virus, but what does that recovery look like? CNN’s Chief Medical Correspondent Dr. Sanjay Gupta looks at some of the long-term symptoms that can linger months later. Listen Now.