Trials involving the Oxford vaccine were initially planned as single dose studies but were later changed to include a second dose when substantial increase in neutralising antibodies were seen when a second dose was administered during the phase-1 trial.
This means the vaccine could significantly slow the spread of the virus, potentially allowing restrictions to be lifted more quickly. Other countries have followed suit, some recommending dosing intervals no more than six weeks apart; the USA has recommended sticking with the three or four weeks between doses in line with most clinical-trial results.
Reuters shared the letter - which it obtained from the university through a Freedom of Information request - with three different experts in medical ethics.
They also report that due to the time required to manufacture the second dose, there were "delays in administration of the second dose for a large number of trial participants who received the two-dose schedule".
The spokesman's suggestion that no error was made is contradicted by documents produced a year ago by Oxford and its vaccine partner, drugs giant AstraZeneca PLC. Totally, 17,177 participants were included in the efficacy analysis - 8,597 who received the vaccine and 8,580 control participants.
Russian Federation became the first country to register a Covid vaccine for emergency use back in August, despite it only having been tested on a handful of people.
But questions surrounding the clinical trials continue to plague the vaccine.
G7 foreign ministers express deep concern over Myanmar coup
Aung San Suu Kyi went on to win two elections, one in 2015 and another in 2020 with the latter being contested by the military. Myanmar Army armored vehicles drive past a street after they seized power in a coup in Mandalay, Myanmar February 2, 2021.
"There is still insufficient data for those aged above 65". The company has said it is doing its best to boost supplies.
Mene Pangalos, executive vice-president of biopharmaceuticals research and development at AstraZeneca, said no patients experienced severe COVID-19 or required hospitalization three weeks after receiving a first dose, and that efficacy appeared to increase up to 12 weeks after the initial shot.
Asked whether the United Kingdom had contacted RDIF about acquiring some of the vaccine, Mr Dmitriev said: 'Not yet, but I think once we have proven the efficacy of an AstraZeneca-Sputnik combination, I think it is possible to have this discussion with the United Kingdom'. Combining data from the two dosing regimens resulted in an efficacy of 70.4%.
As of February 1, more than 1.6 million doses had been administered in France.
Pollard and colleagues found vaccine efficacy was 54.9% (95% CI 32.7%-69.7%) at less than 6 weeks, and was supported by data showing binding antibody responses more than two-fold higher after 12 or more weeks versus an interval of less than 6 weeks in adults ages 18-55.
"But I think there is a bit of hope in that, when we look at studies that have been done of the vaccines from any country in the world, including those with the variants, if they look at severe disease in those studies then we're still seeing very good protection".
