Hanna Barczyk for NPR / Juan Gaertner / Science Source / Sanchit Khanna / Hindustan Times via Getty Images

Hanna Barczyk for NPR / Juan Gaertner / Science Source / Sanchit Khanna / Hindustan Times via Getty Images

For the second year in a row, the global pandemic has dominated our blog – and the attention of our readers.

Our top stories on COVID showcase the ever-changing nature of the crisis. In February, readers were curious about the mysterious decline in cases in India, which increased again in the spring, creating another popular story. In summer they wanted to read about the Delta variant, only to shift the focus to Omicron in winter. The readers wanted to know the whole time: Do vaccines and masks still work against all coronavirus mutations?

That list of stories, says NPR correspondent Michaeleen Doucleff, “really shows how much has happened in just one year.”

“Last December we had doubts that the variants would change the course of the pandemic,” she adds. “Here we are 12 months later, still fighting the delta rise and facing another variant that looks even more contagious.”

Out of the 321 global health and development stories published on our blog in 2021, here are the 11 most popular COVID stories sorted by page views.

Heavily vaccinated Israel saw a dramatic increase in new COVID cases. Here’s why

What happened? Here are six lessons from Israel’s experience – and one emerging question for the future of the pandemic. Published on August 20, 2021

Medics in Jerusalem transferred a COVID-19 patient to Hadassah Ein Kerem Hospital. Many hospitals in Israel were at full capacity this summer after a sharp spike in coronavirus infections.

Menahem Kahana / AFP via Getty Images

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Medics in Jerusalem transferred a COVID-19 patient to Hadassah Ein Kerem Hospital. Many hospitals in Israel were at full capacity this summer after a sharp spike in coronavirus infections.

Menahem Kahana / AFP via Getty Images

How SARS-CoV-2 in American deer could change the course of the global pandemic

Scientists have evidence that SARS-CoV-2 circulates in white-tailed deer in the United States. Published on November 10, 2021

A new study suggests that white-tailed deer like the one here could carry the SARS-CoV-2 virus indefinitely and could transmit it to humans at regular intervals.

Matt Stone / MediaNews Group / Boston Herald via Getty Images

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Matt Stone / MediaNews Group / Boston Herald via Getty Images

A new study suggests that white-tailed deer like the one here could carry the SARS-CoV-2 virus indefinitely and could transmit it to humans at regular intervals.

Matt Stone / MediaNews Group / Boston Herald via Getty Images

Exceptional patient offers surprising clues as to the origin of coronavirus variants

Scientists investigated a possible link between mutations in the UK and South Africa – and those of a patient in Boston who had been living, growing viruses in his body for five months. Published on February 5, 2021

How India went from a glimmer of hope to a world record for most COVID cases in one day

The number of COVID-19 cases in India fell to a record low in February. Now a shocking surge is causing health systems – and possibly law and order – to collapse. What went wrong? Published on April 22, 2021

Relatives carried the wrapped body of a family member who had died of COVID-19 from an ambulance to a crematorium in New Delhi.

T. Narayan / Bloomberg via Getty Images

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T. Narayan / Bloomberg via Getty Images

Relatives carried the wrapped body of a family member who had died of COVID-19 from an ambulance to a crematorium in New Delhi.

T. Narayan / Bloomberg via Getty Images

New studies find evidence of “superhuman” immunity to COVID-19 in some people

For example, some scientists describe the results of a series of studies that looked at the antibodies made by people who were infected with the coronavirus and then received an mRNA vaccine. Published on September 7, 2021

The endgame of COVID: Scientists have an inkling of where SARS-CoV-2 is going

Pandemic predictions were made – and then things would change. But based on models and studies (including a 1980s test that injected virus into human noses), researchers have a new endgame thesis. Published October 29, 2021

The Delta variant isn’t just hyper-contagious. It also grows faster in you

New research from China suggests that people infected with the Delta variant have, on average, about 1,000 times more virus in their airways than those infected with the original strain. Published July 21, 2021

What the rapid spread of Omicron could mean for the US – and the world

The variant has spread with remarkable speed in South Africa – and discovered in at least 60 other countries. Specialists try to figure out the next level of this unpleasant variant. Released Dec 10, 2021

Studies indicate a sharp decrease in vaccination protection compared to Omicron – but give cause for optimism

In small studies in South Africa and Germany, the results show a significant decrease in the ability of vaccines to neutralize this variant. But there are other findings that are encouraging. Published December 8, 2021

A man is vaccinated against COVID-19 at a clinic in Johannesburg, South Africa. The Omicron variant appears to be causing an upswing in South Africa. New studies suggest that vaccines against this variant may not be as effective, but a booster may help.

Shiraaz Mohamed / AP

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Shiraaz Mohamed / AP

A man is vaccinated against COVID-19 at a clinic in Johannesburg, South Africa. The Omicron variant appears to be causing an upswing in South Africa. New studies suggest that vaccines against this variant may not be as effective, but a booster may help.

Shiraaz Mohamed / AP

The Secret of India’s Decreasing COVID-19 Cases

From 100,000 cases a day in September, India fell to about 10,000 a day this year. Is it climate Demographics? Mask requirement? Scientists are looking for answers. Published on February 1, 2021

A mural in New Delhi is part of India’s public health news. The country has seen a dramatic drop in new cases since peaking in Fall 2020, but researchers aren’t sure why.

Sanchit Khanna / Hindustan Times via Getty Images

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A mural in New Delhi is part of India’s public health news. The country has seen a dramatic drop in new cases since peaking in Fall 2020, but researchers aren’t sure why.

Sanchit Khanna / Hindustan Times via Getty Images

Coronavirus FAQ: Why am I suddenly hearing so much about KF94 masks?

There are N95s that come out on top when it comes to protection. There are KN95s that you can easily buy – except that the quality can vary. But earlier this year, South Korea’s KF94 masks started to generate a lot of buzz. Published on January 22, 2021

South Korea’s KF94 mask hides the Mona Lisas smile – but how effective is it in preventing the spread of the coronavirus? Masked pedestrians stroll through a shopping area in Seoul.

Chung Sung-Jun / Getty Images

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South Korea’s KF94 mask hides the Mona Lisas smile – but how effective is it in preventing the spread of the coronavirus? Masked pedestrians stroll through a shopping area in Seoul.

Chung Sung-Jun / Getty Images