The World Health Organization warned Monday that children across the world will die as the coronavirus pandemic forces some countries to temporarily halt vaccinations for other deadly diseases such as polio.

Even as hospitals and governors raise the alarm about a shortage of ventilators, some critical care physicians are questioning the widespread use of the breathing machines for Covid-19 patients, saying that large numbers of patients could instead be treated with less intensive respiratory support.

As the coronavirus landed in the U.S. in January, scientists began whispering about an apparent difference from its notorious sibling, the virus that caused SARS: People infected with this one could easily infect others — even if they had no symptoms.

The White House coronavirus response coordinator said Monday that she is "very worried about every city in the United States" and projects 100,000 to 200,000 American deaths as a best case scenario.