Michaeleen Doucleff

There's cause for concern. But how concerned should we be? Here's a rundown of the current thinking on key issues as transmission, severity of disease — and effectiveness of vaccines.

The European Center for Disease Prevention and Control says the COVID-19 variant spreading across England appears to be more contagious. Scientists examine what that means for the rest of the world.

Dr. Chizoba Barbara Wonodi of Johns Hopkins University explains why a strategy to vaccinate everyone may not be the best approach to fighting the virus in lower-income countries such as Nigeria.

Experts say low-risk people in the U.S. will likely be immunized before many high-risk people in poor countries.

At least three coronavirus vaccines have been deemed effective. Some Western countries will start vaccination as early as this month. But it's unclear when less wealthy nations will get the vaccines.

In 2015, the mosquito-borne virus Zika exploded in South America. Health experts predicted it would erupt in Africa. But a major outbreak never happened. Now scientists think they understand why.

"The vaccine is on its way, folks," Dr. Anthony Fauci announced. But what about the rest of world, especially families in poorer counties. Is the vaccine "on its way for them?"

Wealthy countries have a strategy to secure doses of any forthcoming vaccines. And that's creating a problem for lower-income nations.

The culprit is air pollution — a problem around the globe, from homes where people cook using coal and wood to the smoky streets of San Francisco when wildfires were raging.

On an eight-hour Emirates flight, with mask-wearing enforced, a whopping 27 coronavirus-positive people boarded the plane in Dubai. Guess how many passengers got infected?

How risky is it to travel on the plane during the pandemic? Scientists are beginning to answer that question, and are trying to figure out what passengers can do to lower their exposure risk.

There's evidence that certain vaccines boost the body's defense against many kinds of illness. Scientists are investigating whether this benefit extends to protection from COVID-19.

As scientists race to develop a vaccine specific for COVID-19, some researchers are testing an old vaccine, that's been proven safe and is cheap to manufacture, to see if it could slow the pandemic.

As if the pandemic weren't enough, people are wondering whether climate change will cause pathogens buried in frozen ground to come back to life as the Arctic warms. How worried should we be?

Here are recommendations from researchers on how to stave off infectious diseases such as the common cold and the flu during a flight.

Some parents swear by it. They say it's the only way they and their babies get any sleep. Others parents say it's harmful. So what does the science say? Here we separate fiction from fact.

Last fall, Merck said it would stop selling its rotavirus vaccine to West Africa and redirect its supply to China at a higher price. After NPR broke the story, the situation changed — for the good.

For the first time, the World Health Organization has estimated how well the world is doing to prevent low-weight births. The progress is too slow, researchers say.

A dengue vaccine put thousands of kids at risk for a deadly condition. Some scientists say the manufacturer and health officials did too little to warn parents in the Philippines.

A dengue vaccine put thousands of kids at risk for a deadly disorder. Some scientists says the manufacturer did too little to warn parents in the Philippines.