MARY LOUISE KELLY, HOST:
Encouraging news today about the prospects for a vaccine to prevent COVID-19. NPR science correspondent Joe Palca has more.
JOE PALCA, BYLINE: Dan Barouch is a vaccine maker at Beth Israel Deaconess Hospital. He says there's a lot to learn before scientists can make a vaccine for COVID-19.
DAN BAROUCH: For example, it is not yet known whether people who are infected with COVID and recover are then protected against reexposure.
PALCA: In other words, if you get sick once, will your immune system protect you from getting sick again?
BAROUCH: And it is also not yet known whether people who are vaccinated will be protected against infection.
PALCA: To begin to answer those questions, Barouch and his colleagues performed a series of experiments with rhesus macaque monkeys. In two papers published in the journal Science, Barouch says nine monkeys who were infected with the coronavirus and recovered did not get reinfected when exposed to the virus. Another group of monkeys received several different experimental vaccines. Here, the results were a bit more equivocal.
BAROUCH: Some of the animals were completely protected. Some were partially protected. But nevertheless, what we showed was that the vaccine-induced antibody response correlated with the extent of protection.
PALCA: That is, the better the antibody response, the better the vaccine. A third paper in the journal Nature Communication involves smaller animals, mice and guinea pigs. Here, the researchers studied a vaccine made by Inovio already being tested in humans. David Weiner of the Wistar Institute is a co-author on that paper. He says he and his colleagues were looking for the kind of immune responses that would prevent illness.
DAVID WEINER: And we can get those after one or two immunizations in 100% of animals.
PALCA: Now, mice and guinea pigs and monkeys are not humans. But as Dan Barouch puts it...
BAROUCH: These studies increase our optimism that the development of a vaccine will likely be possible.
PALCA: Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.