Nobody is eager to be stuck by a needle twice, so naturally many would view a COVID-19 vaccine that provides disease protection after a single injection as a good thing.
Two new studies released Thursday suggest that might be possible.
Both studies involved rhesus macaque monkeys. In one study, researchers from Beth Israel Deaconess Medical Center and pharmaceutical company Janssen injected the animals either with a vaccine candidate or an inert placebo. Six weeks after they were injected, the researchers exposed the animals to the coronavirus, both by putting it in their noses and down their throats.
All 20 of the animals receiving the inert, placebo injection showed signs of infection in both their lungs and noses after being exposed to the virus. But one of the vaccine candidates seemed quite effective in preventing infection. In the six animals vaccinated with this particular candidate, none had signs of infection in their lungs, and only one had a sign of infection in the nose.
Candidate Janssen's parent company, Johnson & Johnson, has decided to start testing in humans. Initial trials started this week.