New study would evaluate a lower dosage of vaccine
AstraZeneca is likely to run an additional global trial to assess the efficacy of its COVID-19 vaccine candidate, its chief executive Pascal Soriot was quoted as saying on Thursday following questions over the results from the company’s late-stage study.
The company is also working with regulators to investigate a lower dosage of the vaccine that performed better than a full dosage, a spokesman for the company said.
“Now that we’ve found what looks like a better efficacy, we have to validate this, so we need to do an additional study,” to evaluate the lower dosage, Soriot said in a Bloomberg News report.
Soriot said it would probably be another “international study, but this one could be faster because we know the efficacy is high so we need a smaller number of patients.”
Asked by Reuters about the Bloomberg report on the additional trial, a spokesman for AstraZeneca said there is “strong merit in continuing to further investigate the half-dose/full dose regimen.”
“We are further evaluating the data and will work with regulators on the best approach for further evaluation. This would add to data from existing trials which are currently being prepared for regulatory submission,” he said.
The news comes as AstraZeneca faces questions about its success rate that some experts say could hinder its chances of getting speedy U.S. and EU regulatory approval.
Several scientists have raised doubts about the robustness of results showing the experimental vaccine was 90 per cent effective in a sub-group of trial participants who, by error initially, received a half dose followed by a full dose.
At the heart of concerns is that the trial’s most promising result of 90 per cent comes from a sub-group analysis — a technique many scientists say can produce spurious readings.
Dr. Matthew Oughton, an attending physician at Jewish General Hospital in Montreal who is not involved in the vaccine research, said earlier on Thursday that additional clinical trials could help provide better answers to questions as they come up about how effective and safe the vaccine is.
Dr. Howard Njoo, Canada’s deputy chief public health officer, told reporters that vaccine clinical trial data from press releases are being heavily scrutinized.
“The lesson for all of us is we need to do our due diligence,” Njoo said of the approval process for vaccine candidates.
Federal officials say Canada has agreements with these vaccine manufacturers: AstraZeneca, GlaxoSmithKline/Sanofi, Johnson & Johnson, Medicago, Moderna, Novavax and Pfizer.
Njoo said the hope is to immunize three million Canadians in priority groups initially with two doses.
Health Canada must first authorize any vaccines as both safe and effective and check that the products are manufactured to high-quality standards before people receive any immunizations.