Air turbulence: When can it become dangerous?
Flight turbulence like that encountered by a Singapore Airlines flight on Tuesday is extremely common, but there's one aspect of severe turbulence an aviation expert says can lead to serious injury.
The protection that vaccines give against coronavirus infection, and potentially severe disease, is highly likely to wane over time so vaccine campaigns will continue for years to come, scientists told the British government's advisory group.
"It is highly likely that vaccine induced immunity to SARS-CoV-2 infection, and potentially severe disease (but probably to a lesser extent) will wane over time," according to an executive summary of a document considered by the government's Scientific Advisory Group for Emergencies (SAGE).
"It is therefore likely that there will be vaccination campaigns against SARS-CoV-2 for many years to come, but currently we do not know what will be the optimal required frequency for re-vaccination to protect the vulnerable from COVID disease," the scientists said.
The document, titled "How long will vaccines continue to protect against COVID?," was written by prominent virologists and epidemiologists from Imperial College London, University of Birmingham and Public Health England.
Britain has approved and is using three shots - Oxford-AstraZeneca, Pfizer-BioNTech and Moderna - in a mass vaccination program that started in December 2020.
Real world data show that these vaccines protect with 95% or greater effectiveness against the Alpha variant that dominated in Britain in early 2021, the scientists said, although the ability of the shots to protect against infection and onward transmission was lower.
They said it might be expected that vaccine effectiveness would remain high for severe disease but effectiveness against mild disease and infection could fall off over time.
Anecdotal reports from Britain and Israel, which rolled out a comprehensive early campaign, supported that concept, they said.
Israel will begin offering a third shot of the Pfizer-BioNTech COVID-19 vaccine to people aged over 60, a world first in efforts to slow the spread of the highly contagious Delta variant.
Since the emergence of the Delta variant, the Israeli health ministry has twice reported a drop in the vaccine's efficacy against infection and a slight decrease in its protection against severe disease.
In a separate report to the U.K. government on July 22, scientists said there was a "realistic possibility" that new strains could emerge that could lead to more widespread severe disease or evade the impact of the current vaccines.
The emergence of such strains could lead to a return to tighter controls and lockdowns, with a consequent impact on economic activity.
Flight turbulence like that encountered by a Singapore Airlines flight on Tuesday is extremely common, but there's one aspect of severe turbulence an aviation expert says can lead to serious injury.
British Columbia serial killer Robert Pickton was attacked and sustained life-threatening injuries in a Quebec prison Sunday in what officials described as a 'major assault.'
New inflation data is 'welcome news' for consumers and an economist says it could signal the possibility for a interest rate cut as several core measures also continue to ease.
House of Commons Speaker Greg Fergus is facing fresh Conservative-led calls to resign, this time over "very partisan" and 'inflammatory' language used – the Liberals say mistakenly – to promote an upcoming event.
Ontario Provincial Police continue to investigate a long weekend fatal boat collision on Bobs Lake, north of Kingston, Ont.
In his latest column for CTVNews.ca, former NDP leader Tom Mulcair argues that if there's an unofficial frontrunner in the eventual race to replace Justin Trudeau as Liberal leader, it has to be former Bank of Canada governor Mark Carney.
The organizers of a month-long boycott of Loblaw-owned stores say they've decided to extend the boycott past May.
Donald Trump's reelection campaign called 'The Apprentice,' a film about the former U.S. president in the 1980s, 'pure fiction' and vowed legal action following its premiere at the Cannes Film Festival. But director Ali Abbasi is offering to privately screen the film for Trump.
The trial of a Winnipeg man who has admitted to killing four women has heard he searched the internet to look up the definition of what it means to be a serial killer.
Public libraries in Atlantic Canada are now lending a broader range of items.
Flashes of purple darting across the sky mixed with the serenading sound of songs will be noticed more with spring in full force in Manitoba.
Catching 'em all with impressive speed, a 7-year-old boy from Windsor, Ont. who only started his competitive Pokémon journey seven months ago has already levelled up to compete at a world championship level.
A sanctuary dedicated to animals with disabilities is celebrating the third birthday of one of its most popular residents.
2b Theatre recently moved into the old Video Difference building, seeking to transform it into an artistic hub, meeting space, and temporary housing unit for visiting performers in Halifax.
A B.C. woman says her service dog pulled her from a lake moments before she had a seizure, saving her life.
A Starbucks fan — whose name is Winter — is visiting Canada on a purposeful journey that began with a random idea at one of the coffee chain's stores in Texas.
Members of Piapot First Nation, students from the University of Winnipeg and various other professionals are learning new techniques that will hopefully be used for ground searches of potential unmarked grave sites in the future.
ALS patient Mathew Brown said he’s hopeful for future ALS patients after news this week of research at Western University of a potential cure for ALS.