Only 1.5% of those eligible to receive the new Covid booster jab - which was tested on just 8 mice, not humans, before the FDA approved it - have taken the updated shot, according to data released Thursday by the Centers for Disease Control and Prevention (CDC).
Approximately 4.4 million people have taken the tweaked booster shot from Pfizer and Moderna after they were rolled out three weeks ago around Labor Day weekend. The bivalent shots were designed to target both the original Covid-19 strain, and the currently circulating Omicron subvariants BA.4 and BA.5, NBC News reports.
"I would expect a much higher proportion of Americans to have gotten the booster by this point," said Yale Medicine infectious diseases specialist, Dr. Scott Robers, who said the relatively low uptake was "demoralizing."
"The fact that this booster came out days before Biden said the pandemic is over is a huge mixed message," said Roberts, who added that a lack of public awareness surrounding the shots - or the 'prevailing narrative that the pandemic is ending' might have hindered the rollout. "Now it’s going to be that much harder to convince those at risk who are on the fence to get a booster."
As of Tuesday, the US had shipped over 25 million boosters to tens of thousands of sites.
Approximately 80% of the US population has received at least one shot of the primary Covid vaccine, and almost 68% are considered 'fully vaccinated' by the CDC - meaning they've received two doses of Pfizer or Moderna's offering, or one dose of Johnson & Johnson's vaccine.
experts are still gathering real-world data, since the shots were distributed without results from human trials. Laboratory studies found that the boosters generated strong antibody responses against BA.4 and BA.5, and human trial data showed that a similar vaccine yielded a strong antibody response against the initial omicron strain, BA.1.
Authorization of the bivalent boosters for children ages 5 to 11 may be just weeks away, Dr. Peter Marks, director of the Food and Drug Administration’s Center for Biologics Evaluation and Research, said at an event this week with the Covid-19 Vaccine Education and Equity Project. -NBC News
Word of the slow uptake comes after Denmark recommended that only those over the age of 50, or who are at risk of developing severe Covid-19, receive the vaccine.