'A beautiful soul': Funeral held for baby boy killed in wrong-way crash on Highway 401
A funeral was held on Wednesday for a three-month-old boy who died after being involved in a wrong-way crash on Highway 401 in Whitby last week.
Scientists in the U.K. believe they have discovered the reason why some people experienced the very rare side-effect of blood clots after receiving the AstraZeneca COVID-19 vaccine.
The findings, published in the journal Science Advances on Wednesday, reveal that a protein found in blood is drawn to a component of the vaccine, which triggers a reaction from the body’s immune system that can result in clots.
The AstraZeneca vaccine, like other viral vector vaccines, uses a safe virus as a “host” to deliver genetic information about the COVID-19 spike protein to the vaccine recipient's cells so that they can build an immune response and create antibodies.
The AstraZeneca COVID-19 vaccine uses a cold virus from a chimpanzee, also known as a chimpanzee adenovirus, as the delivery system. This is because it cannot make humans sick – and, because they have not been exposed to it before, they will not have antibodies against it.
Viral vector vaccines modify the delivery virus so that it cannot spread, they simply delivers the instructions for the body’s cells.
By analyzing the chimpanzee adenovirus used by AstraZeneca with cryo-electron microscopy, which allows for molecular-level details to be seen, researchers found that the adenovirus attracts the blood protein known as “platelet factor 4” to it.
Cryo-electron microscopy involves flash-freezing the study subject and then bombarding them with electrons to produce microscope images of individual molecules. Those are then used to reconstruct the structure of the subject in minute detail.
The cryo-electron microscopy image of the chimpanzee adenovirus, which is less than 100 nanometres across, that delivers the Oxford-AstraZeneca vaccine. (Science Advances Journal)
The cryo-electron microscopy image of the chimpanzee adenovirus which delivers the Oxford-AstraZeneca vaccine. (Science Advances Journal)
Platelet factor 4 is implicated in the origins of another clotting event called heparin-induced thrombocytopenia (HIT), which causes changes to the blood that may cause a clot to form in the blood vessels.
Researchers posit that the body begins to attack the platelets that are attached to the adenovirus, after mistaking it as part of the foreign virus. Then, when antibodies are released into the bloodstream to attack, they clump together with the platelet factor 4 and can form a dangerous blood clot known as vaccine-induced thrombotic thrombocytopenia or VITT.
Because that sequence of events in the body is so specific, it may explain why the development of blood clots after receiving the vaccine is such a rare phenomenon.
The U.K. findings echo a Canadian study conducted by researchers at McMaster University in Hamilton, Ont., and published this July in the scientific journal Nature.
In the Canadian study, researchers analyzed blood samples from five patients with VITT and compared them to blood samples of 10 patients with HIT and 10 samples from healthy individuals.
Looking at the amino acids of the interaction between the VITT antibodies and platelet factor 4 protein, researchers found eight specific amino acids on the platelet protein that were identical to the binding site of HIT, which they believe could explain the similar patterns in how the blood clots form after vaccination.
However the U.K. study was able to render the highest resolution of the adenovirus used in the AstraZeneca COVID-19 vaccine to date, allowing them to better understand its primary cell attachment proteins and its structure.
VITT has been linked to at least one death in Canada after an Ontario man received the AstraZeneca vaccine in May, and to 73 deaths out of close to 50 million doses of AstraZeneca administered in the U.K.
The Public Health Agency of Canada’s National Advisory Committee of Immunization stopped recommending AstraZeneca’s COVID-19 vaccine as a second dose option after some Canadian recipients reported blood clots in the spring of 2021.
Researchers in the U.K. hope their study findings can be used to improve future vaccines and reduce the risk of blood clots.
-----
With files from CTVNews.ca writer Brooklyn Neustaeter
A funeral was held on Wednesday for a three-month-old boy who died after being involved in a wrong-way crash on Highway 401 in Whitby last week.
There has been a "sophisticated" cybersecurity breach detected on B.C. government networks, Premier David Eby confirmed Wednesday evening.
Toronto police say a man was taken into custody outside Drake's Bridle Path mansion Wednesday afternoon after he tried to gain access to the residence.
U.S. President Joe Biden said for the first time Wednesday he would halt shipments of American weapons to Israel, which he acknowledged have been used to kill civilians in Gaza, if Prime Minister Benjamin Netanyahu orders a major invasion of the city of Rafah.
Rookie goalie Arturs Silovs will start in net for the Canucks as Vancouver kicks off a second-round series against the Edmonton Oilers Wednesday night.
One of the Indian nationals accused of murdering British Columbia Sikh activist Hardeep Singh Nijjar says in a social media video that he received a Canadian study permit with the help of an Indian immigration consultancy.
Pfizer has agreed to settle more than 10,000 lawsuits about cancer risks related to the now discontinued heartburn drug Zantac, Bloomberg News reported on Wednesday, citing people familiar with the deal.
Quebec Premier Francois Legault is defending his comments about a new history museum after he was accused by a prominent First Nations group of trying to erase their history.
Independent U.S. presidential candidate Robert F. Kennedy Jr. had a parasite in his brain more than a decade ago, but has fully recovered, his campaign said, after the New York Times reported about the ailment.
The stakes have been set for a bet between Vancouver and Edmonton's mayors on who will win Round 2 of the Stanley Cup playoffs.
A grieving mother is hosting a helmet drive in the hopes of protecting children on Manitoba First Nations from a similar tragedy that killed her daughter.
A chicken farmer near Mattawa made an 'eggstraordinary' find Friday morning when she discovered one of her hens laid an egg close to three times the size of an average large chicken egg.
A P.E.I. lighthouse and a New Brunswick river are being honoured in a Canada Post series.
An Ontario man says he paid more than $7,700 for a luxury villa he found on a popular travel website -- but the listing was fake.
Whether passionate about Poirot or hungry for Holmes, Winnipeg mystery obsessives have had a local haunt for over 30 years in which to search out their latest page-turners.
Eighty-two-year-old Susan Neufeldt and 90-year-old Ulrich Richter are no spring chickens, but their love blossomed over the weekend with their wedding at Pine View Manor just outside of Rosthern.
Alberta Ballet's double-bill production of 'Der Wolf' and 'The Rite of Spring' marks not only its final show of the season, but the last production for twin sisters Alexandra and Jennifer Gibson.
A mother goose and her goslings caused a bit of a traffic jam on a busy stretch of the Trans-Canada Highway near Vancouver Saturday.