The manufacturer of the only monkeypox vaccine approved by the Food and Drug Administration has written to federal health officials warning against a plan to split doses to stretch the supply.
In a letter sent to Health and Human Services Secretary Xavier Becerra, and Food and Drug Administration Commissioner Robert M Califf, Bavarian Nordic CEO Paul Chaplin wrote: “We do have some reservations … due to the very limited safety data available.”
Conducting further studies before overhauling the nation’s monkeypox vaccine strategy would be “prudent”, Mr Chaplin said. The letter was obtained and first reported on by The Washington Post.
Mr Chaplin further said that his company had been “inundated with calls from US state government officials with questions and concerns” about how to implement the new plan.
On Wednesday, administration officials acknowledged the concerns of the manufacturer but said the new strategy would still go ahead.
“We’ve had conversations with them about this, and so has FDA,” Secretary Becerra said in an interview. “We wouldn’t have moved forward unless we thought it was safe and effective, and if FDA hadn’t dotted its I’s and crossed its T’s.”
The Post reports that some administration officials believe that Bavarian Nordic’s concerns stem from the potential loss in profits through lower sales from a reduced need for orders from the US, currently in the grip of a growing monkeypox crisis.
A company representative, speaking anonymously to the paper, insisted that the concerns were based on issues of safety.
The Biden administration has said it still plans to procure more than 5 million additional single-dose vials from Bavarian Nordic by 2023.
US health officials on Tuesday authorised a plan to stretch the nation’s limited supply of monkeypox vaccine by giving people just one-fifth the usual dose, citing research suggesting that the reduced amount is about as effective.
The so-called dose-sparing approach also calls for administering the Jynneos vaccine with an injection just under the skin rather than into deeper tissue — a practice that may rev up the immune system better. Recipients would still get two shots spaced four weeks apart.
“It’s safe, it’s effective, and it will significantly scale the volume of vaccine doses available for communities across the country,” Robert Fenton, the White House’s monkeypox response coordinator, told reporters.
Mr Califf, who authorised the new approach on Tuesday, cited a 2015 study into the two-dose vaccine that he said showed the strategy would be effective. Mr Chaplin, the Bavarian Nordic CEO, was one of the authors of the study.
“The results of this study demonstrate that intradermal administration produces similar immune response to subcutaneous administration,” Mr Califf said on Tuesday. The FDA commissioner first publicly floated the dose-splitting strategy last week.
The highly unusual step is a stark acknowledgment that the US currently lacks the supplies needed to vaccinate everyone seeking protection from the rapidly spreading virus.
That includes 1.6 million to 1.7 million Americans considered by federal officials to be at the highest risk from the disease, primarily men with HIV or men who have a higher risk of contracting it. Vaccinating that group would require more than 3.2 million shots.
White House officials said the new policy would immediately multiply the 440,000 currently available as full doses into more than 2 million smaller doses.
There have been approximately 9,500 cases of monkeypox confirmed in the US, overwhelmingly among gay and bisexual men, and local officials have pressed the White House to deliver more vaccine doses amid surging demand.
At present authorities in New York and other hotspots have been delaying second doses to focus on giving initial shots to try and curb the spread.
The US declared the monkeypox outbreak to be a public health emergency on 5 August.
With additional reporting from the Associated Press
