Johnson & Johnson’s long-awaited vaccine seems to protect against COVID-19 with a single shot – not as strong as some two-shot rivals, but still potentially useful for a world in dire need of doses. J&J said on Friday that in the US and seven other countries, the single-injection vaccine was 66% effective overall in preventing moderate to severe disease and much more protective – 85% – against the worst symptoms.
There was some geographical variation. The vaccine worked better in the US – 72% effective against moderate to severe COVID-19 – compared to 57% in South Africa, where it was against a mutant virus easier to spread.
“Single-dose gambling is definitely worth it,” Dr. Mathai Mammen, global head of research for Janssen J & J’s pharmaceutical unit, told the Associated Press.
With vaccinations started globally, experts relied on a single-dose vaccine that would extend supply and avoid the logistical nightmare of causing people to return for recalls.
But with other competing vaccines that have been shown to be 95% effective after two doses, the question is whether a slightly lower protection is an acceptable compromise to get more blows quickly.
The company said within a week it would file an application for emergency use in the US and then abroad. It expects to deliver 100 million US doses by June and expects to have a few ready to ship as soon as authorities give the green light.
These are the preliminary findings of a study of 44,000 volunteers, which has not yet been completed. The researchers looked at diseases that started 28 days after vaccination – about when, if participants received a variety of two doses in return, they would have needed another shot.
After day 28, no one who was vaccinated needed hospitalization or died regardless of whether they were exposed to “ordinary COVID or these particularly ugly variants,” Mammen said. When the vaccines became infected, they had a milder disease.
To defeat the scourge that has killed more than 2 million people worldwide will require the vaccination of billions, and the shots fired in various countries so far require two doses a few weeks away for complete protection. Early data is mixed with exactly how well all the different types work, but the photos taken by Pfizer and Modern appear to be approximately 95% protective after the second dose.
But amid shortages, some countries have recommended delaying the second dose of certain vaccines, with little data on how this would affect protection.
All COVID-19 vaccines train the body to recognize the new coronavirus, usually by spotting the spikey protein that covers it. But they are done in very different ways.
J & J’s shot uses a virus as cold as a Trojan horse to carry the spike gene into the body, where cells make harmless copies of the protein to create the immune system where the real virus appears.
Rival AstraZeneca makes a vaccine similar to the cancer virus, which requires two doses. Both AstraZeneca and J&J vaccines can be stored in the refrigerator, making them easier to transport and use in developing countries than frozen ones made by Pfizer and Moderna.
It is not clear how well the AstraZeneca version works, used in the UK and a few other countries. Tests in the UK, South Africa and Brazil have suggested that two doses are about 70% effective, although there is little data available on how much protection older adults receive specifically. An ongoing US study may provide more information.
J&J said its vaccine works consistently in a wide range of people: one-third of participants were over 60 and more than 40 percent had other diseases, putting them at risk for severe COVID-19 , including obesity, diabetes and HIV.
J&J said the vaccine is safe, with similar reactions to other COVID-19 vaccines, such as fever, that occur when the immune system is revitalized.
Although it published some details, the company said there were no serious allergic reactions. But occasionally, other COVID-19 vaccines trigger such reactions, which can be reversed if treated promptly – and authorities have warned people to be on the lookout for any type of vaccine used.
J&J covered its bets with a study of a two-dose version of its vaccine, which is still ongoing.
Friday’s interim results follow another vaccine in the final tests. Novavax reported this week that its vaccine is 89% effective in a study in the UK and that it appears to work – though not as well – against new mutant versions of the virus circulating in the UK and South Africa. A larger study in the US and Mexico still enrolls volunteers.