Europe's medicines regulator is expecting to receive a formal Covid-19 vaccine application from Johnson & Johnson in the next few days.
"Probably as early as next week," Marco Cavaleri, chair of the European Medicines Agency's vaccine evaluation team, told Reuters today.
He noted that the EMA has been conducting a rolling review of the vaccine for sometime. "Mid-March is reasonable for the EMA decision," he said.
Unlike the other coronavirus vaccines, Johnson & Johnson's only requires one dose.
The EMA, Mr Cavaleri added, has been in contact to date with about 50 pharmaceutical companies working on Covid vaccines.
Regarding the Russia's Sputnik V vaccine, he said the agency is in constant contact with the company producing it.
"There is a constructive cooperation. If there are no problems with the answers we receive on the subject of the production phase, the rolling review could start within a matter of weeks," he said.
The EMA is also in contact with the Chinese companies developing vaccines, particularly Sinovac Biotech, but the process for the Chinese vaccine is a few steps behind the Russian one, he said.
Also today, the Netherlands-based drugs regulatory body said it had launched a real-time review of CureVac's Covid-19 vaccine to speed up potential approvals.
The EMA's human medicines committee will review data from ongoing trials of the German biopharmaceutical firm's vaccine until there is enough clinical data for approval, it said.
Having started mass testing of its vaccine candidate, which uses next-generation mRNA technology, in Europe and Latin America in December, CureVac expects an initial readout from the study in March or April.
The EMA said its decision to start the "rolling review" of the vaccine, CVnCoV, was based on its preliminary results from laboratory studies and early clinical studies in adults.
Marco Cavaleri also said today that the EMA is planning to speed up assessments of any Covid vaccines that are modified to protect against variants of the virus.
He said there should be no need for lengthy large-scale trials like those needed to evaluate the first coronavirus vaccines, since tweaks for new variants can be tested on smaller groups.
"We are working on updated guidelines, assuming that we cannot ask for large Phase III trials. This will allow us to go faster," said Mr Cavaleri.
"We will ask for much smaller trials, with a few hundred participants, rather than 30,000 to 40,000," he told Reuters. He said the EMA would focus primarily on immune response data.
Drugmakers including Pfizer, Moderna and AstraZeneca have been testing their Covid-19 vaccines against several fast-spreading, more infectious variants of the novel coronavirus.
Variants which emerged in Brazil (known as P.1.), Britain (known as B.1.1.7) and South Africa (known as B.1.351) have already spread around the world, piling more pressure on governments struggling to tame the pandemic which has killed almost 2.5 million people.
Normally, an EMA approval requires extensive studies with large numbers, starting with safety and ending with efficacy.
