A top official heading the Trump administration’s federal vaccine program said on Jan. 3 that the government is considering giving people a half-dose of Moderna’s COVID-19 vaccine in order to get more people inoculated faster.
The vaccine regimen for Moderna’s product involves an initial inoculation, followed by a booster shot 28 days later. Pfizer’s vaccine also follows a similar regimen.
“We know that for the Moderna vaccine, giving half of the dose to people between the ages of 18 and 55, two doses, half the dose, which means exactly achieving the objective of immunizing double the number of people with the doses we have,” Slaoui said.
“We know it induces identical immune response” to the full dose, he said, adding that the FDA would ultimately decide whether to accelerate injecting half the volume of the vaccine in order to get more people inoculated faster.
Slaoui said on Jan. 3 that in the previous 72 hours, another 1.5 million people had received shots.
CBS’s Margaret Brennan asked Slaoui whether it was reasonable to use the existing vaccine supply to “hit as many people at once” rather than hold back half the doses for a second shot, the idea being to “space out the time between doses” and administer the second booster shot as more doses are manufactured.
Slaoui said the effectiveness data of the vaccine is based on a two-dose regimen at a specific interval and that using up the existing supply on the first wave of shots without clarity on when the second dose would be available may not achieve the goal of providing protection.
“We have no data after one dose,” he said, adding that leaving “people a month, two months, three months with maybe incomplete immunity, waning immunity, maybe even the wrong kind of immune response induced,” would “not be responsible,” referring to Brennan’s suggestion.
He said the correct approach is to maintain the two-dose regimen as the second dose “gives you 10 times higher immune response than the first dose,” adding that a better solution to getting more people vaccinated quickly is to reduce dosage size in the Moderna vaccine.
“I think that’s a more responsible approach that will be based on facts and data to immunize more people. And, of course, we continue to produce more vaccine doses,” he said.
It comes amid concerns that vaccine rollout in the United States has been slow. Trump administration officials had said they expected 20 million people would get vaccinated against COVID-19 by the end of the year, but the figure now stands at around one-third of the initial projection.
Slaoui was asked in the interview whether Operation Warp Speed could help accelerate vaccine rollout, to which he replied: “We stand by here to help any specific request.
“We will do the best we can, as we have done over the last eight months, to make these vaccines, indeed, make it into the arms of people.”