MedPage Today 2020.11.09

Reaction was generally — but not universally — positive to Pfizer’s and BioNTech’s announcement that their mRNA COVID-19 vaccine candidate was more than 90% effective in interim phase III trial results.

Matthew Spinelli, MD, of the University of California San Francisco, said he is “overall pretty excited” about the results, and added there was a “real desire to know” this data, given not only its importance, but also to ready the public health logistics that will be required for vaccine distribution.

Reaction was generally — but not universally — positive to Pfizer’s and BioNTech’s announcement that their mRNA COVID-19 vaccine candidate was more than 90% effective in interim phase III trial results.

Matthew Spinelli, MD, of the University of California San Francisco, said he is “overall pretty excited” about the results, and added there was a “real desire to know” this data, given not only its importance, but also to ready the public health logistics that will be required for vaccine distribution.

“It’s the silver lining of science by press release,” he told MedPage Today, describing how hearing the headlines without data might be “discomfiting for a scientist, but it’s helpful to have a sense of what the pre-print or publication will ultimately look like because this is going to require an incredible public health infrastructure.”

Spinelli referred to the challenges of storage during vaccine distribution. The vaccine is a two-dose regimen and needs to be stored in a medical grade deep freezer, at an average of -103º F.

“It’s more complicated than the average vaccine; it’s going to require a lot of logistical thinking,” he said, and the resulting vaccination campaign will be “on a scale we haven’t seen.”

These concerns were echoed by analysts, such as Philipp Rosenbaum, PhD, senior infectious diseases analyst at GlobalData, who pointed out that “concerns about the supply and distribution of COVID-19 vaccines, especially for mRNA vaccine[s] such as Pfizer’s that require deep-freeze storage and have a rather short shelf-life at refrigerator temperatures, will only add barriers.”

“As a proof of concept, it’s incredible,” Spinelli added, though it doesn’t negate the need to develop additional vaccines, which may work better in specific populations.

 

The results released Monday were from analysis of 94 confirmed COVID-19 cases in trial participants who had received the full two-dose series and were followed for at least 7 days after the second dose. In the full trial, participants are to be followed for 2 years.

So far, the study has enrolled 42,538 participants, including nearly 39,000 who had received the scheduled two doses as of Nov. 8. However, it was unclear how many of those had gone 7 days past their second dose and were included in the interim analysis.

For purposes of regulatory filings, final efficacy analyses will be conducted when the trial has accrued 164 confirmed COVID-19 cases.

But not everyone greeted the topline results with enthusiasm. Washington, D.C.-based advocacy group Public Citizen slammed the release of “preliminary and incomplete clinical trial data” results by press release, calling it “bad science.”

“Crucial information absent from the companies’ announcement is any evidence that the vaccine prevents serious COVID-19 cases or reduces hospitalizations and deaths due to the disease,” said Michael Carome, MD, director of Public Citizen’s Health Research Group, in a statement.

Carome pointed out that safety data were not released (the companies’ press release only said the independent data monitoring committee hadn’t identified “any serious safety concerns”), and the trial results have not been independently reviewed by an FDA advisory committee, calling for enthusiasm for the vaccine to be “tempered.”

Spinelli raised some of the same concerns, saying we have yet to see safety data, and raised questions about the durability of immunity to SARS-CoV-2 conferred by the vaccine.

If full data bears out the interim 90% efficacy, it would be comparable to vaccines for other respiratory illnesses, such as rotavirus and pertussis, Spinelli said, and obviously higher than the seasonal influenza vaccine, which the CDC estimated at 45% vaccine efficacy in 2019-2020.

Reference