J&J said on Friday that in the United States and seven other countries, the single injection vaccine was 66% effective in preventing moderate to severe illnesses and much more protective – 85% – against the most severe symptoms.
There was some geographical variation. The vaccine worked best in the US – 72% effective against moderate to severe COVID-19 – compared to 57% in South Africa, where it was against an easier to spread mutant virus.
“Playing with a shot was certainly worth it,” said Dr. Mathai Mammen, head of global research at J&J’s Janssen Pharmaceuticals unit, to the Associated Press.
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With vaccinations getting off to a rough start all over the world, experts were counting on a single dose vaccine that would increase scarce supplies and avoid the logistical nightmare of getting people back for reinforcements.
But with some other competing vaccines that have been shown to be 95% effective after two doses, the question is whether a little less protection is an acceptable trade-off to get more injections quickly.
The company said that within a week it will file an emergency use request in the US and then abroad. She hopes to supply the United States with 100 million doses by June, and hopes to have some ready for shipment as soon as the authorities give the green light.
These are preliminary findings from a study of 44,000 volunteers that has not yet been completed. The researchers tracked illnesses from 28 days after vaccination – around the time when, if participants were receiving a range of two doses, they would need another injection.
After the 28th, no one who was vaccinated needed hospitalization or died, regardless of whether they were exposed to “regular COVID or these particularly unpleasant variants,” said Mammen. When the vaccinees were infected, they had a milder illness.
Defeating the scourge that killed more than 2 million people worldwide will require vaccinations for billions, and vaccines in different countries so far require two doses a few weeks apart for full protection. The first data is mixed about exactly how all the different types work, but the photos taken by Pfizer and Moderna seem to have about 95% protection after the second dose.
But in the midst of scarcity, some countries have advised to postpone the second dose of certain vaccines, with little data on how it would affect protection.
All COVID-19 vaccines train the body to recognize the new coronavirus, usually by detecting the spiny protein that surrounds it. But they are done in very different ways.
The J&J injection uses a cold virus like a Trojan horse to carry the spike gene to the body, where cells make harmless copies of the protein to prepare the immune system in case the real virus appears.
Rival AstraZeneca manufactures a vaccine against the similar cold virus, which requires two doses. AstraZeneca and J&J vaccines can be stored in a refrigerator, making them easier to ship and use in developing countries than frozen ones made by Pfizer and Moderna.
It is unclear how well the AstraZeneca version, being used in Britain and several other countries, works. Tests in Britain, South Africa and Brazil have suggested that two doses are about 70% effective, although there are doubts about how much protection the elderly receive. A study in progress in the USA may provide more information.
J&J said its vaccine works consistently for a wide range of people: a third of the participants were over 60 and over 40% had other illnesses that put them at risk for severe COVID-19, including obesity, diabetes and HIV.
J&J said the vaccine is safe, with reactions similar to other injections of COVID-19, such as the fever that occurs when the immune system is accelerated.
Although it released few details, the company said there were no serious allergic reactions. But occasionally, other COVID-19 vaccines trigger such reactions, which can be reversed if promptly treated – and authorities have warned people to be on the lookout, regardless of the type of vaccine used.
J&J had covered its bets with a study of a two-dose version of its vaccine, which is still in progress.
Friday’s provisional results come in the wake of another vaccine in final testing. Novavax reported this week that his vaccine appears 89% effective in a study in the United Kingdom and that it also appears to work – albeit not so well – against new mutant versions of the virus circulating in Britain and South Africa. USA and Mexico is still recruiting volunteers.
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