The European Medicines Agency (EMA), the EU drug regulator, recommended issuing a conditional marketing authorization for Moderna’s COVID-19 vaccine, which follows the authorization of the Pfizer-BioNTech vaccine in late December. 

“This vaccine provides us with another tool to overcome the current emergency,” Emer Cooke, Executive Director of EMA, said in the press release. “It is a testament to the efforts and commitment of all involved that we have this second positive vaccine recommendation just short of a year since the pandemic was declared by WHO.” 

The European Commission is expected to grant the vaccine authorization in the coming days. The Moderna vaccine has already been authorized and rolled out in the US, Canada, and Israel. 

The EMA has received criticism for its delay in reviewing the AstraZeneca-University of Oxford vaccine, which has been approved in Britain and India. The drug company has reportedly already submitted its data to the EMA for a conditional marketing authorization as part of the ongoing rolling review process.

US Experts Consider Administering Half Doses of Moderna Vaccine

Meanwhile, in the US, officials at the National Institutes of Health, in collaboration with Moderna, were examining whether vaccine doses can be halved while maintaining their effectiveness, in an effort to extend vaccine supplies.

The prospect of changing the dosing regimen was raised by Moncef Slaoui, head of the US Operation Warp Speed, in an interview with CBS “Face the Nation” on Sunday. 

“We know [a 50-microgram half dose] induces identical immune responses to the 100-microgram doses, therefore we are in discussions with Moderna and with the FDA – ultimately it will be an FDA decision – to accelerate by injecting half the volume,” said Slaoui. 

According to Moderna’s Phase II clinical trial data submitted to the US Food and Drug Administration (FDA), the immune responses between the full dose and half dose among participants aged 18 to 55 were comparable when maintained on the schedule with a 28 day interval. 

The research could continue for at least two months, according to John Mascola, director of the Vaccine Research Center at the NIH. “It’s important to do these analyses that we’re doing, and have all that data in our pocket in the event that there’s a need to use it,” he said in an interview with the New York Times on Tuesday. 

US Food and Drug Administration Pushes Back Against UK Plans To Extend Interval Between Pfizer doses

The FDA, the agency responsible for any changes to vaccine dosing or schedules, issued a strongly worded statement on Monday night, pushing back against a recent UK policy decision permitting an extension of the interval between the first and second dose of the Pfizer vaccine upon – and in some cases, even a mix and match vaccines. 

“These are all reasonable questions to consider and evaluate in clinical trials. However, at this time, suggesting changes to the FDA-authorized dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence,” said Stephen Hahn, FDA Commissioner, in the statement. 

“Without appropriate data supporting such changes in vaccine administration, we run a significant risk of placing public health at risk, undermining the historic vaccination efforts to protect the population from COVID-19.”

Germany Also Decides Against Delaying Second COVID-19 Dose

Germany also decided to stick to the standard vaccination regimen proposed by Pfizer and BioNTech, after considering following the lead of Britain to delay the administration of the second dose. 

The German independent expert panel advised against making changes to the regimen without sufficient evidence. 

“My impression is that it makes a lot of sense, especially with these sensitive issues, where trust and reliability are important, that we stick to the approval,” said German health minister Jens Spahn at a press conference on Wednesday.

Image Credits: Tanveer Shaikh/Flickr, Bret Bostock/Flickr.