As the world grapples with Covid-19, influenza isn’t getting much attention these days. But the flu’s global impact is staggering: three million to five million cases of severe illness every year, and up to 650,000 deaths. Every few decades, a new flu strain spills over from animals and leads to a pandemic.

The deadly toll of influenza is all the more striking when you consider that we have had vaccines to fight it for eight decades. But they remain mediocre. A flu shot is good for only one flu season, and its effectiveness typically reaches somewhere between 40 and 60 percent. In some years it’s as low as 10 percent.

Continue reading “First, Impressive Vaccines for Covid. Next Up: The Flu.” →

A British clinical trial found no sign of danger in getting a flu shot and a second dose of a Covid-19 vaccine at the same time, results that support the advice of U.S. health authorities and are welcome news for strained health care workers as flu season hits.

In the study, doctors recruited 679 people from April to June across Britain. At the time, all of the volunteers had received a first dose of a Covid-19 vaccine, either from AstraZeneca or Pfizer-BioNTech, the two vaccines first authorized there.

Continue reading “A study finds no signs of trouble in getting flu and Covid shots at the same time.” →

Ancient human footprints preserved in the ground across the White Sands National Park in New Mexico are astonishingly old, scientists reported on Thursday, dating back about 23,000 years to the Ice Age.

The results, if they hold up to scrutiny, would rejuvenate the scientific debate about how humans first spread across the Americas, implying that they did so at a time when massive glaciers covered much of their path.

Researchers who have argued for such an early arrival hailed the new study as firm proof.

Continue reading “Ancient Footprints Push Back Date of Human Arrival in the Americas” →

For half a billion years or so, our ancestors sprouted tails. As fish, they used their tails to swim through the Cambrian seas. Much later, when they evolved into primates, their tails helped them stay balanced as they raced from branch to branch through Eocene jungles. But then, roughly 25 million years ago, the tails disappeared.

Charles Darwin first recognized this change in our ancient anatomy. But how and why it happened has remained a mystery.

Continue reading “How Humans Lost Their Tails” →

A second dose of Johnson & Johnson’s vaccine substantially increased its protection against Covid-19, the company announced Tuesday morning.

In a clinical trial, researchers found that two doses of the vaccine delivered 94 percent efficacy against mild to severe Covid-19 in the United States, up from 74 percent conferred with a single shot, the company reported. And two shots showed 100 percent efficacy against severe disease, although that estimate had a wide range of uncertainty.

Continue reading “An extra J. & J. shot substantially boosts protection against Covid, the company reports.” →