Vaccine manufacturers told lawmakers they’re on track to deliver hundreds of millions of doses of vaccine by mid-summer, but whether the available vaccines and those in line for possible FDA approval can stand up to new variants remains unclear.
“The most pressing challenge that we have right now is the lack of supply of vaccine doses,” said House Committee on Energy and Commerce’s Oversight and Investigations Subcommittee Chair Diana DeGette (D-Colo.). She stressed Americans’ frustration last year when vaccination allocations to states fell short of what was needed to vaccinate high-risk populations.
But manufacturers reassured the chairwoman that their companies had overcome initial hurdles and increased production.
“We anticipate all 300 million contracted doses will be made available for shipment to points of use as directed by the U.S. government by the end of July,” John Young, group president and chief business officer of Pfizer, told the subcommittee during a hearing on Tuesday.
That’s enough doses to vaccinate up to 150 million Americans, he noted.
Pfizer, which was the first company to receive an emergency use authorization (EUA) for a COVID-19 vaccine from the FDA, has shipped 40 million doses as of February 17 to sites across the U.S., as directed by the federal government, he said.
The company has been able to scale up production through investments to manufacturing sites and new manufacturing lines and by contracting with two additional manufacturers. Additional doses were also made available following the FDA’s approval of a six-dose label for each vial, and through increasing batch sizes and reducing cycle times, Young said.
These advances have allowed the company to make 13 million doses available each week by mid-March — a significant jump from the four to five million doses available per week in early February. In total, 120 million vaccine doses will be ready by the end of March and another 80 million are expected to be available by the end of May.
Moderna, according to company president Stephen Hoge, MD, has delivered over 54 million vaccine doses to sites around the country. The company plans to deliver its first 100 million doses of vaccine by the end of March, having doubled its monthly deliver since the end of 2020, and is looking to double its monthly shipments by April to over 40 million doses per month.
Acknowledging that both drug companies faced initial obstacles to ramping up vaccine production, DeGette asked Hoge whether Moderna was on track to also make 300 million doses available to Americans by the end of July.
“[W]e do believe we’re on track to meet those deadlines,” Hoge said.
DeGette also asked Richard Nettles, MD, vice president of medical affairs for Janssen Pharmaceutical Companies of Johnson & Johnson, whether the company would be able to meet its own projected goal of 100 million doses by the end of June, if the J&J vaccine receives an EUA.
“Yes, we are on track to deliver the 100 million doses by the end of June,” Nettles said.
He noted later in the hearing that 20 million vaccine doses will be available by the end of March and that the company is ready to ship “immediately upon emergency use authorization nearly 4 million doses of our vaccine.”
In his opening testimony, Nettles shared that clinical trials found complete protection against COVID-19 hospitalization and death 28 days after vaccination. The J&J vaccine was also shown to be 85% effective in preventing severe disease, including in countries where new coronavirus variants are emerging, and has been shown to be 72% effective in the U.S. in preventing moderate-to-severe disease.
An FDA advisory committee, an independent body of experts, will meet on Friday to discuss the benefit-risk profile of the vaccine and to determine whether to recommend that the agency provide J&J with an EUA. That authorization, if it occurs, could happen as early as this weekend.
Responding to Variants
Phase III trials of the Pfizer and Moderna vaccines demonstrated efficacy rates of 95% and 94%, respectively, as witnesses from both companies testified. Several committee members, however, expressed concerns about these vaccines’ ability to respond to emerging variants.
Young noted that Pfizer’s mRNA platform enables scientists to develop “boosting doses” if necessary and to quickly modify the sequence of the vaccine to respond to changes in the virus, if data suggest that changes to virus could impact the level of protection afforded by Pfizer’s vaccine.
Having conducted in vitro studies on immune responses triggered by the vaccine against variants from the U.K. and South Africa, “we believe the vaccine should provide protection from these variants,” Young said, adding that “to date we’ve seen no real-world evidence to suggest a significant reduction in protection provided by our current vaccine.”
He also shared that Pfizer “hope[s] to initiate a study to investigate the effectiveness of a third booster of vaccine,” and is already discussing trial designs to examine the safety and immunogenicity of an updated vaccine with the FDA.
For Moderna’s part, Hoge, in his written testimony, said the company is closely tracking emerging variants and testing its existing vaccine against them. Moderna is also studying potential booster shots of the original vaccine or a special version intended to respond to the variants.
Pediatric Populations, Supply Shortages
Committee members, including Rep. Kim Schrier (D-Wash.), also asked witnesses about their companies’ plans to develop a vaccine for children.
Pfizer is currently conducting studies in subjects ages 12-15 and plans to begin studies in children under the age of 11 soon, Young said.
Hoge said that the Moderna vaccine is being actively studied in participants ages 12-18 and “moving into younger populations in the near term.”
Finally, when asked one by one whether vaccine manufacturers are worried about access to raw materials as more companies are expected to receive EUAs, none of the panelists expressed concern.
“We think we have the supplies and consumables we need,” Hoge said.
And asked by the Committee’s Ranking Member Rep. Morgan Griffith (R-Va.) whether witnesses needed anything more from the federal government in order to accelerate production, no one had any clear demands.
“All we need is the continued partnership of the government,” Young said.
Source: MedicalNewsToday.com
