(Reuters) – AstraZeneca is likely to conduct a further global study to assess the effectiveness of the COVID-19 vaccine at a lower dose, the CEO was quoted as saying in a late-stage study on Thursday.
Instead of adding the study to an ongoing U.S. process, AstraZeneca could launch a new study to evaluate a lower dose of the vaccine that performs better than the full dose, Pascal Soriot told Bloomberg News.
“Now that we’ve found better efficacy, we need to confirm this, so we need to do more research,” he said, adding that the new, probably global study could be faster because fewer subjects would be needed as efficacy was already known to be high.
The news comes when AstraZeneca faces issues of failure that some experts say could hinder the chances of obtaining official approval from the US and the EU as soon as possible.
Several scientists have expressed doubts about the reliability of the results published on Monday that the experimental vaccine was 90% effective in a subset of experimental participants who initially received half a dose by mistake and then a full dose.
Soriot said he did not expect further negotiations to delay British and European official approvals.
An AstraZeneca spokesman, on a question about the Bloomberg report, said he had serious merits in continuing to investigate half-dose / full-dose dosing. Additional insights from the data would be added to existing studies that are being prepared for regulatory submission, he said.
Running another test shouldn’t be too much of a complication for the British pharmaceutical maker in the race to develop a vaccine to curb the epidemic that is killing more than a million people and fooling the global economy.
Helen Fletcher, a professor of immunology at the School of Hygiene and Tropical Medicine in London, says another study will not necessarily delay the green light, as the effectiveness of the higher-dose system remains in line with the World Health Organization’s goal. It was not uncommon to do new tests on approved vaccines, he said.
The vaccine is one of three that can be approved before the end of the year. This month, Pfizer and Moderna reported that about 95% of their vaccines were effective in preventing disease and setting the bar high.
Nevertheless, the AstraZeneca shot developed at the University of Oxford is cheaper, easier to distribute and scalable faster than its rivals.
Britain on Friday asked its drug regulator to assess whether the vaccine candidate meets strict safety standards for temporary delivery, a step towards starting the introduction of the vaccine before the end of the year.
AstraZeneca expects 4 million doses to be available in the UK by the end of next month.
An expert-reviewed analysis of the data from the new study will be published in a medical journal in the coming weeks.
The European Medicines Agency did not respond immediately to requests for comments.
AstraZeneca told Reuters on Thursday that the half-dose administration had been reviewed and approved by independent data security observers and the UK regulator, adding that the regulator had publicly confirmed it was “no concern”.
However, approval by the U.S. Food and Drug Administration (FDA) may take longer because the agency is unlikely to approve the vaccine based on studies elsewhere, especially considering issues over the results, Soriot said.
AstraZeneca head of research, Mene Pangalos, told Reuters on Monday that the company is starting talks with the FDA to change the negotiation plan to add a more efficient dosing system.
In some countries, licensing is expected before the end of the year.
Astrazeneca has contracted shipments of the vaccines to several countries, including 120 million doses to Japan and 85 million doses to Australia.
Australian Prime Minister Scott Morrison, speaking to the media, expressed confidence in the vaccine, which is being manufactured by the country’s biomedical giant, CSL Ltd.
The Indian Serum Institute is testing the vaccine there.
“Even the lowest efficacy results are 60-70%, which means a viable vaccination against the virus,” the institute said in a statement, adding that the tests are running smoothly.