麻豆影视

Coronavirus

    • Second-dose struggles: normal immune responses more intense than 1st dose for some

    Share

    Becca Young woke up the day after getting her second dose of a COVID-19 vaccine with a body so sore and head so achy it felt as if she'd been dancing and drinking at a raging party the night before.

    Young, a trivia host from Kitchener, Ont., and her husband Matt Neil received their second mRNA vaccine on Saturday. But while Neil felt fine aside froma minor headache, Young could barely get out of bed for most of Sunday.

    鈥淪ore arm, sore back, just super achy. And my head - it was kind of reminiscent of an alcohol hangover,鈥 she said with a laugh. 鈥淚t's funny because the first vaccine I got was Pfizer and the second was Moderna. So I did get a cocktail.鈥

    Young, who had only a sore arm after her first dose, is among many Canadians to experience stronger reactions to the second jab, and experts say that's normal.

    Nafissa Ismail, director of the Neuro-Immunology, Stress and Endocrinology (NISE) Laboratory at the University of Ottawa, said while the immune system generally responds less severely when re-exposed to a pathogen a second time, that's not how our COVID-19 vaccines work.

    Instead, mRNA and viral-vector vaccines give cells instructions on how to detect the coronavirus's spike protein so that the body can mount a defence if it meets the actual virus.

    鈥淭hey are not injecting us with a weakened form of the virus or a dead form of the virus,鈥 Ismail said, referring to common methods of other vaccines. 鈥淪o the first time we get the message, our immune system hasn't yet produced antibodies.

    鈥淏ut when we get the second dose ... there's this dual action where some antibodies are already there and ready to fight, plus we're asking the immune system to make more antibodies. So symptoms tend to get amplified.鈥

    Everyone's immune system responds differently to vaccines, which Ismail said is the reason so many varying side effects are reported. Soreness, headache, fatigue and fever symptoms tend to last only a day or two, but can linger for some people.

    Younger adults, who typically have robust immune systems, are more likely to experience routine reactions, Ismail added, while women also generally have stronger responses for the same reason.

    Health Canada's report on COVID-19 vaccine side effects, which includes reactions disclosed by people following first or second doses, shows 79.1 per cent of adverse events are reported by women - a rate of 38.6 reports per 100,000 doses administered, compared to 11.6 from men.

    The agency's website says it's unclear whether women are more likely to report a reaction, or if biological differences are to blame, but it adds that similar trends have been seen in other countries.

    Steven Kerfoot, an immunologist with Western University, said stronger second-dose reactions to COVID-19 vaccines haven't been 鈥渁bsolutely confirmed鈥 as something that's happening regularly, but anecdotally - and in Kerfoot's own experience - it does seem to be the case.

    Mixing and matching vaccines could spark a more intense reaction for some Canadians, like Kerfoot, who received Oxford-AstraZeneca first and an mRNA vaccine the second time around. But blending the similarly structured mRNA jabs likely doesn't cause stronger side effects, Kerfoot added, nor should the timing between doses.

    The difference is what's going on biologically after each dose, he said.

    Mild unpleasantness felt within hours-to-days of dose 1 is the immune system 鈥渂ecoming suspicious (of) a viral infection,鈥 Kerfoot said, and it responds in general ways to fight it off.

    Aches and the pain, feeling tired, 鈥渢hat's your body declaring a shutdown, (saying) 'stay in bed, conserve your energy,鈥' Kerfoot said, while a fever raises the body'stemperature to limit a virus's ability to replicate.

    鈥淭hose (reactions) can happen after the first dose and the second dose. But the difference with the second dose is now you have other very specific detectors, especially antibodies, in place,鈥 he said.

    鈥淪o it's reasonable that people would feel more symptoms the second time around because the additional antibody detection system is ready to respond more quickly and strongly.鈥

    While a strong response is normal, the absence of a reaction doesn't necessarily signify a weak immune system or an ineffective vaccine.

    Christopher Richardson, a microbiology expert at Dalhousie University, said his reaction was 鈥渜uite intense鈥 after his first dose but not his second.

    鈥淓veryone's a little bit different,鈥 Richardson said, positing that perhaps enough antibodies and T-cells are produced after some peoples' first dose that the immune response is more controlled the second time around.

    Kerfoot added most people who don't exhibit post-vaccine reactions should still be 鈥渧ery confident鈥 that the shot did work.

    Young, who moved her trivia nights to virtual platforms when the pandemic began, said 24 hours of achiness was a good trade-off for the protection she now has against COVID-19, and the closer it brings her to hosting in-person events again.

    鈥淭hat's well worth feeling a little bit crappy for one day,鈥 she said.

    This report by The Canadian Press was first published July 7, 2021.

    CTVNews.ca Top Stories

    Why brain aging can vary dramatically between people

    Researchers are uncovering deeper insights into how the human brain ages and what factors may be tied to healthier cognitive aging, including exercising, avoiding tobacco, speaking a second language or even playing a musical instrument.

    The union representing some 1,200 dockworkers at the Port of Montreal has overwhelmingly rejected a deal with their employers association.

    A man who was critically injured in a police-involved shooting in Hamilton late Sunday afternoon has died in hospital, says the province鈥檚 police watchdog.

    Canada

    World

    Politics

    • Murray Sinclair鈥檚 family members say the late justice and senator has been laid to rest according to his wishes.

    • Prime Minister Justin Trudeau announced voters in Cloverdale鈥擫angley City will pick their next member of Parliament on Dec. 16.

    Health

    Sci-Tech

    Entertainment

    Business

    Lifestyle

    Sports

    Autos

    Local Spotlight

    For the second year in a row, the 鈥楪ift-a-Family鈥 campaign is hoping to make the holidays happier for children and families in need throughout Barrie.

    Some of the most prolific photographers behind CTV Skywatch Pics of the Day use the medium for fun, therapy, and connection.

    A young family from Codroy Valley, N.L., is happy to be on land and resting with their newborn daughter, Miley, after an overwhelming, yet exciting experience at sea.

    As Connor Nijsse prepared to remove some old drywall during his garage renovation, he feared the worst.

    A group of women in Chester, N.S., has been busy on the weekends making quilts 鈥 not for themselves, but for those in need.

    A Vancouver artist whose streetside singing led to a chance encounter with one of the world's biggest musicians is encouraging aspiring performers to try their hand at busking.

    Ten-thousand hand-knit poppies were taken from the Sanctuary Arts Centre and displayed on the fence surrounding the Dartmouth Cenotaph on Monday.

    A Vancouver man is saying goodbye to his nine-to-five and embarking on a road trip from the Canadian Arctic to Antarctica.

    • Weather watchers were treated to an exceptionally rare display on Friday evening as rare cloud formations filled Vancouver skies.

    • For some shoppers it was Nov. 1, but for others the first hints of Christmas - saccharine treats, festive-fragranced candles and gaudily wrapped gift sets - were being noticed in stores long before the final Halloween decor had been cleared.

    • Thousands of people are expected to gather in downtown Vancouver on Monday to observe the city鈥檚 100th Remembrance Day ceremony.

    • Toronto is expected to see an economic boost to the tune of nearly $300 million thanks to Taylor Swift鈥檚 upcoming Eras Tour, which will be making a stop in Canada鈥檚 largest city for a six-show run later this month.

    • One man was transported to hospital early Monday morning after a stabbing in the northwest end of the city, Toronto police say.

    • A pair of 105-mm howitzers bark constantly as they turn plywood tank targets into kindling kilometres away on the windswept landscape of one of Canada's largest military bases.

    • Two semis were among the vehicles involved in a multi-vehicle crash that brought westbound traffic along Stoney Trail Northwest to a standstill on Sunday.

    • NEW THIS MORNING

      NEW THIS MORNING

      An Ottawa boy with a rare disease will be getting the chance to see Taylor Swift in concert after the winner and organizers of an auction held on his behalf gifted the tickets to him.

    • CTVNewsOttawa.ca looks at Remembrance Day ceremonies in Ottawa.

    • After months of controversy surrounding a dog park in Ottawa's west end, a solution has been reached to divide the park in half.

    • The employers association at the Port of Montreal locked out nearly 1,200 longshore workers, bringing a halt to traffic at the port.

    • An elementary school in Greenfield Park on Montreal鈥檚 South Shore is closed after it was the target of an alleged arson attack.

    • Though most businesses are expected to be open on Remembrance Day, there are some establishments that will be closed to commemorate the holiday.

    • Monday is Remembrance Day, a time to honour armed forces members who have died in the line of duty.

    • Boasting 2,300 square metres of skating space at its new location, Edmonton's Rollers Roller Rink believes it is the largest in Canada.

    • A Cape Breton senior recalls her life in German-occupied France, and her mother鈥檚 death, during the Second World War.

    • It's been a trip to cherish for a group of Canadians visiting Belgium this week to honour the legacy of Indigenous soldiers.

    • A pillar in Canada鈥檚 history was honoured in Winnipeg Sunday afternoon, with thousands showing up to pay tribute to the life and legacy of the late Murray Sinclair.

    • Winnipeg police have identified two men involved in a stabbing incident earlier this week.

    • There will be two ceremonies taking place in Regina for Remembrance Day, hosted by the Royal Canadian Legion.

    • Regina author Valerie Crowther is celebrating the release of her book 鈥榃ar Letters: Linking Lives in the Second World War.鈥

    • It was a somber day at Mosaic Stadium as members of the Saskatchewan Roughriders officially cleaned out their stalls and closed the book on the 2024 season.

    • A man has been charged after a stabbing at an apartment building in Kitchener.

    • The Guelph Police Service is putting out a warning after two deaths in the downtown area.

    • Two new tributes to Canada鈥檚 veterans have been unveiled at the Elmira Cenotaph.

    • Saskatchewan RCMP are searching for a suspect after a man was seriously injured in a farm-related incident in Montreal Lake.

    • It was a somber day at Mosaic Stadium as members of the Saskatchewan Roughriders officially cleaned out their stalls and closed the book on the 2024 season.

    • The Regina Rams claimed the Hardy Cup after a hard fought battle against the Saskatoon Huskies 19-14 on Saturday in the first all Saskatchewan U-Sports western conference final since 2002.

    • Emergency crews responded to the scene on Road 68/Highway 2 east of Thamesford around 7 p.m.

    • On Friday, the Sarnia Police Service (SPS) received a report of an alleged abduction in the area of Kathleen Avenue and Walnut Avenue.

    • 11 AM:WATCH LIVE

      11 AM:WATCH LIVE

      The events will start at 10:15 a.m. with a parade that forms up in front of the Delta London Armories, marches east on Dundas Street and turns north onto Waterloo Street to Dufferin Avenue, the west to the Cenotaph.

    • A group of former NHL players faced off against York Regional Police officers in Newmarket Sunday afternoon to raise funds for Special Olympics programs across the province.

    • A driver is facing multiple charges after a multi-vehicle collision on Highway 400 early Sunday morning.

    • The agreed statement of facts was read to the court on Friday in the case of Alex Williams, the 24-year-old jail guard charged last fall with smuggling cannabis and tobacco into Central North Correctional Centre in Penetanguishene.

    • 11 AM:WATCH LIVE

      11 AM:WATCH LIVE

      Representatives of the Windsor Veterans Memorial Services Committee, military representatives, wreath bearers, government officials, and members of the public will attend the Cenotaph at City Hall Square for the outdoor service.

    • One person has been arrested after Chatham-Kent Police Service (CKPS) received multiple complaints about an alleged drunk driver.

    • More details have been released about a police investigation at the Ambassador Bridge that connects Windsor, Ont. and Detroit, MI.

    • Environment Canada says heavy rain and winds could cause power outages on Vancouver Island as an "intense" storm system is set to hit the B.C. coast Sunday.

    • Six deer were struck by vehicles in six different locations in a six-hour period on B.C. highways on Saturday, according to the transportation ministry.

    • The union for locked-out port workers in British Columbia says the BC Maritime Employers Association cut off talks in less than an hour Saturday, refusing to budge on a final offer that the union has so far rejected.

    • The emergency department at South Okanagan General Hospital in Oliver, B.C., will be closed for 31 hours this weekend, the second such closure in a week and the third since the start of November.

    • Police in Kamloops, B.C., are reminding parents and guardians to check their children's Halloween candy after receiving a report of a mother finding a razor blade in one of her daughter's treats.

    • More than two years after Alannah Brown and Douglas Barker were found dead north of Penticton, police are asking for help identifying a vehicle they believe was associated with the crime.

    • The Southern Alberta Recreation Association is officially announcing the Town of Taber as next year鈥檚 host for the Southern Alberta Summer Games.

    • The Lethbridge Hurricanes broke open a close game with three goals in the first two minutes of the third period as they defeated the Warriors 7-3 in a game played Friday night in Moose Jaw.

    • There might not a lot snow just yet, but many southern Albertans are still itching to get outdoors.

    • Police have arrested a 15-year-old in connection with a break-in and $50,000 in damage done to the Centennial Arena in Elliot Lake in September.

    • Mayors of the five largest cities in northern Ontario met in North Bay the last two days to discuss a range of critical issues impacting their cities and the region.

    • Residents in the Sault expressed concerns ranging from vandalism to privacy invasions during recent consultations on the city's plan to install automated speed enforcement cameras.

    N.L.

    Shopping Trends

    The Shopping Trends team is independent of the journalists at 麻豆影视. We may earn a commission when you use our links to shop.聽Read about us.

    Stay Connected
    Follow 麻豆影视