COVID-19 vaccination linked to lower hospitalization risk in real-world data from Scotland

Scotland's vaccination drive appears to be markedly reducing the risk of hospitalization for COVID-19, suggesting that both the Pfizer-BioNTech and Oxford-AstraZeneca shots are highly effective in preventing severe infections, preliminary study findings showed on Monday.

Results of the study, which covered the entire Scottish population of 5.4 million people, showed that by the fourth week after the initial dose, the Pfizer and AstraZeneca vaccines were found to reduce the risk of hospitalization by up to 85 per cent and 94 per cent respectively.

"These results are very encouraging and have given us great reasons to be optimistic for the future," said Aziz Sheikh, a professor at the University of Edinburgh's Usher Institute who co-led the study.

Sheik cautioned at a media briefing that the results are preliminary data, yet to be peer-reviewed by independent scientists, but added: "I am very encouraged. We now have national evidence ... that vaccination provides protection against COVID-19 hospitalizations."

Vaccination results

He said he expected other countries using the same two vaccines and a similar strategy — England and Wales for example — would see a similar positive impact in reducing the number of people being hospitalized with COVID-19.

Data for the vaccines' effect in Scotland was gathered between Dec. 8 and Feb. 15. Researchers said that during this period, 1.14 million vaccines were administered and 21 per cent of Scotland's population had received a first dose.

Among those aged 80 years and over — one of the highest risk groups for COVID-19 — vaccination was associated with an 81 per cent reduction in hospitalization risk in the fourth week, when the results for both vaccines were combined.

Jim McMenamin, Public Health Scotland's COVID-19 incident director, said the findings are particularly important "as we move from expectation to firm evidence of benefit from vaccines."

"Getting the first dose into as many people as possible as quickly as possible seems a sensible way forward," Sheikh said in an interview with CBC News.

Quebec has already adopted the single-dose strategy amid some controversy.

Dr. Gaston De Serres, a medical epidemiologist with Quebec's public health institute, said the real-world vaccine data from Scotland adds to the evidence for other provinces to rethink their plans. 

"You will certainly reduce the number of hospitalizations and deaths … by deferring the second dose and administering the first dose to as many people as possible," he said.