With COVID-19, when can we get back to normal?

With millions of workers and students regularly logging on from home because of the pandemic, the question often arises: When will things return to normal? Some workers in China are returning to work after the virus first emerged in January but they are wearing masks and taking other precautions.

Bill Gates recently repeated his view that broad vaccination will be needed before societies can be completely safe from COVID-19, which might not happen until late 2021. However, he.added that schools "will be able to resume in the fall" in an interview with  Becky Quick on CNBC's Squawk Box that aired Thursday.*

In an interview on PBS Newshour with Judy Woodruff on Tuesday, the billionaire founder of Microsoft said a vaccine will need to become available “before you can be completely safe.” 

In mid-March, experts said it would take a year to 18 months to develop a vaccine, and many companies are working feverishly on the process.

Until vaccinations are developed and widely used, the virus could rebound if strict quarantines aren’t being followed. Even when a vaccine appears, some experts worry some people will refuse to take it.

“The vaccine is critical because until you have that, things aren’t really going to be normal. They could open up to some degree, but the risk of rebound will be there until we have very broad vaccination,” Gates said.

In China, where things are improving, government officials are sending people back to work, but they are wearing masks and having their temperature checked and not gathering in large groups, he said.

Gates had previously said on CBS on April 2 that mass gatherings might need to remain optional or “not come back at all” until populations are widely vaccinated. 

RELATED: COVID-19: Gates warns against mass gatherings before virus vaccinations

The question of when people can gather again is intensely being discussed by businesses and organizations, including colleges that are preparing for summer and fall admissions, with nearly all classes now being conducted online in the U.S.

Gates offered an opinion that while large gatherings might not be able to take place until a vaccine is being widely used, he suggested there could be exceptions for smaller gatherings of young, healthy people, say, in a college classroom. But he was reserved: “We’ll have to figure out how to draw that threshold. We may understand age-specific risk at that point.”

The Bill and Melinda Gates Foundation is working with partners to study other countries and how they are staging return to work and school.  The foundation has focused heavily on health issues in poor countries and Gates said on PBS that emerging countries in Africa and elsewhere are where the most COVID-19 deaths will occur because people often live close to one another and have poor medical care.

A report in the New York Times Wednesday set out four benchmarks for how to decide when people can safely leave their homes, based on insights from experts:

-- When hospitals can safely treat all patients requiring hospitalization without resorting to crisis standards of care.

-- When a state is at least able test everyone who has symptoms.

-- When a state is able to conduct monitoring of confirmed cases and contacts.

-- When there is a sustained reduction in cases for at least 14 days. It can take up to two weeks for symptoms to emerge and any infections that have occurred will take that long to appear.

* Content was updated Thursday.