LONDON – The EMA has issued a positive opinion on Pfizer Inc./Biontech SE’s COVID-19 vaccine, BNT-162b2, becoming the first regulator to recommend a full marketing authorization, rather than approval for emergency use.

The vaccine, now brand named Comirnaty, still has to go through the formality of being approved by EU member state governments, but the EU health commissioner, Stella Kyriakides, has said she expects roll out to start on Dec. 27.

“This is the first marketing authorization of a COVID-19 vaccine in the EU. It is valid in all 27 member states at the same time,” said EMA Executive Director Emer Cooke. “There is a firm scientific foundation for roll out,” she said.

Cooke said the EMA had done in 11 weeks, work that would normally take a year. The agency’s two scientific committees were helped by the quality of the data, she said.

The assessment was done in the face of intense debate, with some calling for approval to be speeded up, while others have expressed concerns the agency was going too fast. “While we’ve taken every step to expedite [the process], ensuring the vaccine’s safety has been our primary concern,” Cooke said. “We at EMA have depended on the strength of the scientific data, nothing else.”

The EMA has weighed up what Harald Enzman, chair of the Committee for Medicinal Products for Human Use (CHMP), described as a “truckload” of data. “Fully assessing this in this timeframe required outstanding teamwork,” he said.

One of the good things about the EMA’s committees is that they have representatives of every member state, making it difficult for any single government to exert political pressure. “The focus was exclusively on the science. We wouldn’t allow political whitewashing. It was a scientific assessment. Full stop,” Enzman said.

To date, Comirnaty has been approved for emergency or temporary use in 15 other countries, including the U.S., meaning approval to market ends if/when the pandemic is declared over.

Cooke said the EMA’s conditional marketing approval will give the agency greater oversight but also “creates additional obligations for us as a regulatory authority.” In addition to providing results from the main phase III trial over the next two years it has to run, Pfizer and Biontech will have to conduct additional studies.

Those will look at how long protection lasts, how good the vaccine is at preventing severe COVID-19 disease, how well it protects immunocompromised people, children and pregnant women, and whether it prevents asymptomatic cases.

“Our work does not stop here,” Cooke said. “We will continue to collect and analyze data on the safety and effectiveness of this vaccine.”

Will vaccines remain effective against new SARS-CoV-2 variant?

In common with many other COVID-19 vaccines in development, Comirnaty delivers genetic instructions for the spike protein by which the virus enters the human host. Given that, news of a major new variant of SARS-CoV-2, with 22 distinct mutations, including some in the spike protein, and now rampant in London and southeast England, has set alarm bells ringing.

Marco Cavaleri, head of Biological Health Threats and Vaccines Strategy at the EMA, said there is not yet enough evidence to give a definitive answer, but it is known that neutralizing antibodies from plasma in people who have been vaccinated recognize the new variant in vitro.

“It is really early to say. You would need to see the virus changing quite substantially. For the time being, we are not worried,” Cavaleri said.

Researchers in the U.K. who first became aware of the new variant on Dec. 11 have spent the past week or so frantically trying to assess the significance of the 22 mutations. A key finding to date is that the variant, named B.1.1.7, has greater transmissibility. The first example was from a swab taken in September. By early November, it accounted for 28% of infections in London, by early December for 62%.

During November, when a national lockdown was in place and incidence of COVID-19 was plateauing or declining, Kent, one of the counties adjoining London, was going against the tide, with infections on the rise.

There was no evidence from behavioral surveys to suggest lockdown regulations were not being observed, leading Public Health England to ask for a review of the genetic epidemiology. That led to identification of B.1.1.7, which computer modeling suggests is more than 70% more transmissible than other SARS-CoV-2 variants that are circulating in the U.K.

“It’s really unusual to have 22 coding changes,” said Wendy Barclay, head of the department of infectious diseases at Imperial College London and a member of the government’s Nervtag (new and emerging virus threats) committee. “We don’t really understand at the moment the biology of all the mutations,” Barclay said. However, there is “biological plausibility” that they change the way the virus enters human cells in a way that could increase transmission.

Peter Horby, professor of emerging infectious diseases at Oxford University and chair of Nervtag, said new evidence is emerging that points to greater ease of transmission. “As of last Friday, we had moderate confidence. Over the weekend more analysis was done on bigger datasets, and this afternoon [Dec. 21] a dozen scientists met and went through the data again and the additional analyses. We now have high confidence it does have a transmission advantage,” Horby said.

It is thought B.1.1.7 originated in the U.K., but the index case has not come to light, so it has not been possible to investigate the features of the infection that might have sparked the mutations.

Since the sequence was released, a handful of cases have been reported from Denmark, Italy and the Netherlands; however, those and other countries in Europe carry out far less viral genome sequencing than the U.K., which to date has contributed 45% of all sequences in the global genomics database.

As to whether B.1.1.7 could limit the effectiveness of COVID-19 vaccines, Barclay said, “We are not completely confident at the moment. It is very important we carry out an analysis of that very quickly. The best way is to look to see if antibodies in vaccine recipients can recognize it. That work is underway at several labs in the U.K.,” she said.

The immune response induced by vaccines is to the spike protein as a whole, Barclay noted. “It’s unlikely a single mutation would throw off all the antibodies, but [the immune response] will possible be compromised to some extent.”