WASHINGTON — The U.S. will likely begin distributing a third vaccine against COVID-19 in the next week, and health officials are girding for questions about which one is best.
The Johnson & Johnson vaccine will offer a single-dose option that could help speed vaccinations. The challenge will be explaining how protective the J&J shot is after the astounding vaccine trial success of two-dose vaccines from Pfizer and Moderna.
Those shots were found to be about 95% effective against symptomatic COVID-19 in clinical trials.
The numbers from J&J are not that high, it's around 72%, but they are not an apples-to-apples comparison.
"That's because the trials were not done head-to-head," Dr. Leana Wen, a CNN medical analyst and former Baltimore public health commissioner said. "It's not as if we had several groups of people -- one group got placebo, one group got Pfizer, one group got Moderna and one group got Johnson & Johnson. That's not how this was done."
Experts also point out the trials were done at different times. The Johnson & Johnson vaccine clinical trials were done while several mutations of the coronavirus were spreading.
Notably, their vaccine was tested in South Africa, where the dominant strain was a variant believed to be more contagious and potentially more serious. In South Africa, the Johnson & Johnson vaccine had a 64% efficacy rate.
Neither Pfizer nor Moderna's vaccine was tested in that environment with that variant. Some studies are underway to see how protective those two vaccines are against the South Africa variants and others.
Experts point out the Johnson & Johnson vaccine offers 86% effective protection against severe forms of coronavirus, keeping patients out of the hospital if they have any symptoms at all.
"The key here isn't that we want to prevent infections, though we do," Dr. Ashish Jha, dean of Brown University's School of Public Health, told CNN. "We want to prevent people from getting really sick and obviously prevent people from dying. And all three of these vaccines appear terrific for that goal."
Bottom line, experts agree that the best vaccine is the one being offered at the time a person becomes eligible in their state.