Simon Clarke, an associate professor in cellular microbiology at the University of Reading, said this week that while both variants had some new features in common, the one found in South Africa "has a number additional mutations" that included more extensive alterations to the spike protein.
There had been 170 cases of the disease in its trial of more 43,000 volunteers, of which 162 were observed in the placebo group and eight in the vaccine group.
But overall, she insisted, her Commission's strategy to snap up orders past year for half a dozen vaccines unproven at the time had been the right one, done in the teeth of fierce global competition.
World Health Organization said there was now no evidence on the need for a booster dose, and said there was no data available on the interchangeability of the Pfizer-BioNTech vaccine with other Covid-19 vaccines.More news: N Korea threatens to build more nukes, cites USA hostility
"This would enable the European Union to purchase up to 600 million doses of this vaccine, which is already being used across the EU". Negotiations are ongoing for one from Novavax.
Maj. -Gen. Dany Fortin, the military commander leading vaccine logistics in Canada, says 171,600 doses of the Moderna vaccine are set to be delivered by the end of next week.
The Moderna vaccine, which was given the green light this week, is to arrive here shortly but it is only expected to add around 10,000 doses per week to HSE stocks initially.
Will delaying the second dose make the vaccine less effective overall?
The vaccines are being delivered to sites across the country as the government commits to offering a vaccine to more than 13 million people in the top four priority groups by mid-February.More news: COVID-19 vaccine not mandatory, health-care workers 'encouraged' to get it
The German health ministry said it has bought an option for an additional 30 million doses directly from BioNTech/Pfizer and 20 million from Curevac, and is negotiating with Moderna. If we're going to get definitive answer they'll be the ones we get it from.
However, the Portuguese health minister Marta Temido, who is now holding the rotating presidency of the EU Council of health ministers, has confirmed this morning that some countries have purchased vaccines on their own side.
It comes as NHS leaders warned this week of London hospitals soon being overwhelmed by Covid-19, with a shortfall of up to 5,500 beds by January 19.
Some 1.3 million people have already received either the Pfizer-BioNTech or Oxford/AstraZeneca jab, with updated figures expected on Thursday. But experts noted that this vaccine and others will still need to be tested against other mutations of concern, and that the new study only looked at one key mutation contained in the variants, not the full variants.More news: Red Deer unemployment rate dips below 10%
But they are logistically very challenging because they must be kept in sub-Arctic temperatures except for limited periods for transport and stocking just before use.