Johnson & Johnson’s long-awaited vaccine appears to protect against COVID-19 all at once – not as strong as some two-dose rivals, but still potentially useful for a world sorely in need of more doses.
J&J said Friday that in the United States and seven other countries, the single-injection vaccine was 66% effective overall in preventing moderate to severe disease and much more protective – 85% – against more severe symptoms.
There was some geographic variation. The vaccine worked better in the United States – 72% effective against moderate to severe COVID-19 – compared to 57% in South Africa, where it faced a mutated virus that was easier to spread.
“The single-dose game was certainly worth it,” Dr Mathai Mammen, head of global research for J&J’s Janssen pharmaceutical unit, told the Associated Press news agency.
With vaccinations off to a rocky start globally, experts were relying on a single-dose vaccine that would increase scarce stocks and avoid the logistical nightmare of getting people to come back for boosters.
But since some other competing vaccines have been shown to be 95% effective after two doses, the question is whether a little less protection is an acceptable compromise to get more vaccines into the guns quickly.
The company said within a week it would file for emergency use in the United States and then overseas. It expects to deliver 100 million doses to the United States by June, and expects to have some ready for shipment as soon as authorities give the green light.
These are preliminary results of a study of 44,000 volunteers that have not yet been completed. Researchers tracked diseases from 28 days after vaccination – around the time, if participants were given a two-dose variety instead, they would have needed another vaccine.
After day 28, no vaccinated person required hospitalization or died, regardless of whether they were exposed to “regular COVID or those particularly nasty variants,” Mammen said. When the vaccinees got infected, they got milder illness.
Beating the scourge that has killed more than two million people worldwide will require immunization of billions, and the vaccines rolled out so far in different countries both require two doses within weeks of each other for full protection. Initial data is mixed on how exactly all of the different types work, but the injections given by Pfizer and Moderna appear to be around 95% protective after the second dose.
But amid the shortages, some countries have advised delaying the second dose of some 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 made in a very different way.
J & J’s shot uses a cold virus like a Trojan horse to carry the spike gene around the body, where cells make harmless copies of the protein to prime the immune system in case the real virus does arise.
Rival AstraZeneca makes a similar cold virus vaccine that 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 the frozen type made by Pfizer and Moderna.
It’s unclear how well the AstraZeneca version, used in the UK and several other countries, works. Tests in the UK, South Africa and Brazil suggest that two doses are around 70% effective, although there are questions about protecting the elderly. 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% had other illnesses that put them at risk for severe COVID-19, including obesity, diabetes and HIV.
J&J said the vaccine was safe, with reactions similar to other COVID-19 injections, such as a fever that occurs when the immune system is reactivated.
Although it released a few details, the company said there were no serious allergic reactions. But sometimes other COVID-19 vaccines trigger such reactions, which can be reversed if treated quickly – and authorities have warned people to be on the lookout for whatever type of vaccine is used.
J&J had hedged 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 final testing. Novavax reported this week that its vaccine appears to be 89% effective in a UK study, and that it also appears to work – but not as well – against new mutated versions of the virus circulating in Britain and South Africa. A larger study in the United States and Mexico is still recruiting volunteers.