The European Union could approve two coronavirus vaccines being tested by Pfizer-BioNTech and Moderna before the end of December, EU Commission president Ursula von der Leyen said tonight.
Ms Von der Leyen said the European Medicines Agency could give "conditional marketing authorisation... as early as the second half of December if all proceeds now without any problem".
Working together, US giant Pfizer and Germany's BioNTech have developed a vaccine the firms say has had successful clinical trials and have sent data to the EMA.
US biotech company Moderna has said its experimental vaccine is 95% effective.
The Amsterdam-based EMA will have to study test results before recommending that Brussels gives its approval, but - speaking after talks with EU leaders - Ms von der Leyen was cautiously optimistic.
The European Union has contracts to reserve hundreds of millions of doses of future vaccines with BioNTech, Purevac, AstraZeneca and Sanofi, if they can be brought to market.
Ms von der Leyen stressed that in the case of US firms, the EMA was in daily contact with its American equivalent the FDA.
"And if all proceeds with no problems, EMA tells us that the conditional marketing authorisation for BioNTech and Moderna could happen as early as the second half of December 2020."
Meanwhile the University of Oxford is expected to release data on the effectiveness of its coronavirus vaccine in the coming weeks, with the latest trial results suggesting it produces a strong immune response in older adults.
The ChAdOx1 nCov-2019 vaccine has been shown to trigger a robust immune response in healthy adults aged 56-69 and people over 70.
Phase two data, published in The Lancet, suggests one of the groups most vulnerable to serious illness and death from Covid-19 could build immunity, researchers say.
According to the researchers, volunteers in the trial demonstrated similar immune responses across all three age groups (18-55, 56-69, and 70 and over).
The study of 560 healthy adults - including 240 over the age of 70 - found the vaccine is better tolerated in older people compared with younger adults.
Volunteers received two doses of the vaccine candidate, or a placebo meningitis vaccine.
No serious adverse health events related to the vaccine were seen in the participants.
The results are consistent with phase one data reported for healthy adults aged 18-55 earlier this year.
Study lead author Professor Andrew Pollard, from the University of Oxford, said: "Immune responses from vaccines are often lessened in older adults because the immune system gradually deteriorates with age, which also leaves older adults more susceptible to infections.
"As a result, it is crucial that Covid-19 vaccines are tested in this group who are also a priority group for immunisation."
Researchers say their findings are promising as they show that the older people are showing a similar immune response to younger adults.
The study also found the vaccine, being developed with AstraZeneca, was less likely to cause local reactions at the injection site and symptoms on the day of vaccination in older adults than in the younger group.
Adverse reactions were mild - injection-site pain and tenderness, fatigue, headache, feverishness and muscle pain - but more common than seen with the control vaccine.
Thirteen serious adverse events occurred in the six months since the first dose was given, none of which were related to either study vaccine.
The authors note some limitations to their study, including that the participants in the oldest age group had an average age of 73-74 and few underlying health conditions, so they may not be representative of the general older population, including those living in residential care settings or aged over 80.
Phase three trials of the vaccine are ongoing, with early efficacy readings possible in the coming weeks.