Joe Palca

An analysis of blood from people who had received the Johnson & Johnson COVID-19 vaccine found a lower level of neutralizing antibodies against viral variants but a strong response involving T cells.

A new study shows that the Johnson and Johnson COVID-19 vaccine may prevent severe disease — even in the face of dangerous coronavirus variants.

NASA's Juno spacecraft traveled to 645 miles above the surface of the solar system's largest moon, Ganymede, on Monday.

On Monday, the visit by NASA's Juno spacecraft will make the first close fly-by of Jupiter's moon Ganymede in more than 20 years. What are scientists hoping to learn?

Instead of putting genetic instructions into people whose cells then make a viral protein, the vaccines from Novavax, Medicago and Sanofi carry a spike protein payload.

Scientists around the world are working on a way to inject vaccines painlessly. The trick is to make the needles so small. they don't interact with the nerve endings that signal pain.

Getting a shot is a pain. But scientists are working on a way to inject a vaccine without the ouch. The solution: a patch that applies an array of microscopic needles and feels like Velcro.

The FDA has said that the COVID-19 vaccine made by Pfizer can be used in children as young as 12, expanding the number of people in the U.S. who qualify for the vaccine.

A large Chinese rocket will drop out of orbit on Saturday, but it will be what is uncontrolled re-entry. Or to put it another way, no one can say for certain exactly where it will land.

Using two different COVID-19 vaccines is a bit like giving the immune system two pictures of the virus, maybe one face-on and one in profile.

Researchers are exploring a mix-and-match strategy for vaccinating people against COVID-19. That means using two different kinds of vaccines instead of the same brand of vaccine twice.

Researchers are trying to come up with tests that can be performed using a blood sample that will determine not only whether a COVID-19 vaccine will work but also for how long.

Scientists are working on boosters to deal with the possibility that current COVID-19 vaccines may eventually wear off — or the virus will mutate in ways that will evade the vaccine's protections.

Fresh off the first powered flight on another world, NASA's Mars 2020 mission has managed another key first that could pave the way for future astronauts.

NASA announced that a small helicopter sent to Mars aboard the Perseverance rover took flight — the first controlled, powered flight on another planet. The helicopter took aerial photos of Mars.

The tiny helicopter took off and hovered briefly — the first such flight on another planet. The Perseverance rover kept tabs on the mission from a viewing point about 60 yards away.

Ingenuity is a tissue box sized helicopter that hovered in the super thin Martian atmosphere, took some pictures and landed safely.

The CDC and FDA have asked to pause using the Johnson & Johnson COVID-19 vaccine after six women developed a rare blood clot condition and one died. The pause is only expected to last days.

The FDA and the Centers for Disease Control and Prevention called for the pause in the use of the Johnson & Johnson vaccine — following reports of blood clots in six women who received the vaccine.

The three vaccines available in the U.S. are safe and effective, but not ideal. Now, work is underway to create more convenient and potent vaccines, including a tablet and nasal spray.