Rob Stein

Updated Oct. 14, 12:45 p.m. ET

If you got the Johnson & Johnson vaccine as your first COVID-19 shot, a booster dose of either the Moderna or Pfizer-BioNTech vaccine apparently could produce a stronger immune response than a second dose of J&J's vaccine. That's the finding of a highly anticipated study released Wednesday.

Carlene Knight's vision was so bad that she couldn't even maneuver around the call center where she works using her cane.

"I was bumping into the cubicles and really scaring people that were sitting at them," says Knight, who was born with a rare genetic eye disease.

But that's changed as a result of volunteering for a landmark medical experiment. Her vision has improved enough for her to make out doorways, navigate hallways, spot objects and even see colors.

"It's nice. I don't scare people and I don't have as many bruises on my body," Knight says, laughing.

Americans may be able to breathe a tentative sigh of relief soon, according to researchers studying the trajectory of the pandemic.

The delta surge appears to be peaking nationally, and cases and deaths will likely decline steadily now through the spring without a significant winter surge, according to a new analysis shared with NPR by a consortium of researchers advising the Centers for Disease Control and Prevention.

A head-to-head comparison of all three COVID-19 vaccines found Moderna is holding up better than Pfizer and the Johnson & Johnson vaccine provides the weakest protection.

But the researchers stressed that all three vaccines are still providing strong protection against people getting so sick that they end up in the hospital.

Like millions of others, Kathleen Hipps thought she was safe from COVID-19 after she got two shots of the Moderna vaccine last spring. So she figured she just had a summer cold when she got the sniffles in July. But then she opened some Vick's VapoRub.

"Anyone who's ever smelled Vick's VapoRub knows how pungent of a smell it is. And I couldn't smell it. And that's how I knew I had COVID," says Hipps, 40, a Los Angeles lawyer who has two young sons.

For the first time, scientists have shown that a new kind of genetic engineering can crash populations of malaria-spreading mosquitoes.

In the landmark study, published Wednesday in the journal Nature Communications, researchers placed the genetically modified mosquitoes in a special laboratory that simulated the conditions in sub-Saharan Africa, where they spread the deadly disease.

Updated July 29, 2021 at 12:05 PM ET

This story has been updated throughout to reflect new research.

New data on the delta variant is coming in, and it's not looking good. The currently authorized vaccines are still very protective, especially against hospitalization and death. But when it comes to getting an asymptomatic or mild case of COVID-19, they may not be quite as protective as they were against earlier strains.

Updated July 9, 2021 at 2:05 PM ET

As the weather warmed up this year, coronavirus case numbers plummeted, and life in the U.S. started to feel almost normal. But in recent weeks, that progress has stalled.

The vaccination campaign has slowed, and the delta variant is spreading rapidly. And new infections, which had started to plateau about a month ago, are going up slightly nationally.

Patrick Doherty had always been very active. He trekked the Himalayas and hiked trails in Spain.

But about a year and a half ago, he noticed pins and needles in his fingers and toes. His feet got cold. And then he started getting out of breath any time he walked his dog up the hills of County Donegal in Ireland where he lives.

"I noticed on some of the larger hill climbs I was getting a bit breathless," says Doherty, 65. "So I realized something was wrong."

Updated June 22, 2021 at 4:25 PM ET

The dangerous Delta variant of the coronavirus is spreading so quickly in the United States that it's likely the mutant strain will become predominant in the nation within weeks, according to federal health officials and a new analysis.

The U.S. is banning the importation of dogs from more than 100 countries for at least a year because of a sharp increase in the number of puppies imported into the country with fraudulent rabies vaccination certificates.

"We're doing this to make sure that we protect the health and safety of dogs that are imported into the United States, as well as protect the public's health," Dr. Emily Pieracci of the Centers for Disease Control and Prevention tells NPR.

As the pandemic calms in the U.S., a growing number of states have started scaling back how often they update their dashboards tracking what's happening with the virus.

The moves are sparking alarm among many public health experts.

For decades, scientists have been prohibited from keeping human embryos alive in their labs for more than 14 days. The prohibition was aimed at avoiding a thicket of ethical issues that would be raised by doing experiments on living human embryos as they continue to develop.

Routine screening for colorectal cancer should begin at age 45 instead of 50, an influential panel is recommending.

Starting routine screening five years earlier could prevent more deaths from colorectal cancer, which is the third-leading cause of cancer deaths in the United States, the U.S. Preventive Services Task Force concluded.

Carlene Knight would love to do things that most people take for granted, such as read books, drive a car, ride a bike, gaze at animals in a zoo and watch movies. She also longs to see expressions on people's faces.

"To be able to see my granddaughter especially — my granddaughter's face," said Knight, 54, who lives outside Portland, Ore. "It would be huge."

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