The updated flu vaccine may work better than last year's did against the H3N2 strain but public health experts once again expect it to underperform.

The updated flu vaccine may work better than last year's did against the H3N2 strain but public health experts once again expect it to underperform.

Flu vaccine to underperform again

Epidemiologist expects less than ideal protection against resurgent H3N2 flu strain but better than 'zero' last year

There are signs the flu season may hit B.C. early and hard and public health officials are warning they expect the flu vaccine to again be less effective than they’d like.

The most dangerous influenza type for vulnerable people is the H3N2 strain that was dominant in last year’s severe flu season.

But because of a genetic mismatch, the vaccine provided last year was useless in warding off H3N2, according to B.C. Centre for Disease Control epidemiologist Dr. Danuta Skowronski.

That component of the vaccine was replaced on orders of the World Health Organization, but preliminary evidence suggests the new version will still not be a good match against H3N2, falling well short of the 60 to 70 per cent protection rates against other flu strains in most years.

“I believe it’s going to be better than last year – in other words I don’t think it’s going to be zero – but by how much, I can’t say,” Skowronski said.

She said there’s good reason to hope it may be 40 to 60 per cent effective overall, adding she continues to recommend the vaccine, particularly for those more vulnerable.

“If you are a high-risk person, especially with heart and lung conditions or elderly, even if you’re looking at vaccine protection of 30, 40 or 50 per cent, you’re still better off than if you’re unvaccinated.”

Flu vaccine will be widely available by November and may be offered sooner than that in high-risk settings like residential care homes.

Epidemiologists had expected H3N2 would be less prevalent this year, with more of a mix of H1N1 and influenza B strains also in circulation, making the mismatch less of a worry.

But Skowronski noted there have already been two H3N2 outbreaks in long-term care homes in B.C.’s Vancouver Coastal health region – one in the summer and another in late September.

“To have had outbreak activity already in the summer is very unusual,” she said. “We are monitoring that closely for the possibility of an early season.”

Apart from last year, B.C. hasn’t seen flu outbreaks this early since 2009.

Last year, with H3N2 widespread and the mismatched vaccine offering no defence, there were 175 outbreaks in long-term care homes.

That was the highest number in more than a decade and twice as many outbreaks as the previous peak year of 2012.

Skowronski acknowledged the mismatch problems threaten to erode public confidence in the flu vaccine but hopes vulnerable patients are not dissuaded.

“For me, it would be a double tragedy, frankly, if coming out of last season our high-risk people lost faith and did not get the vaccine.”

While influenza is a “miserable” illness, Skowronski said it’s not life-threatening to healthy people, for whom vaccination is still encouraged but a matter of personal preference.

About one-third of B.C. residents typically get the flu vaccine each year.

H3N2 vaccines have consistently underperformed in recent years.

Skowronski said more work is needed to try to solve the challenges of accurately gauging the vaccine’s fit against the virus in the lab, and in effectively reproducing a well-matched vaccine without losing its properties.

Also requiring more research, she said, is emerging evidence suggesting repeated use of the vaccine by a given patient diminishes its effectiveness for them in future years.

While the flu vaccine may not perform as well for someone who also received it the previous year as it would for a first-time user, Skowronski said, they’ll still be better off than unvaccinated people.

Her team is trying to recruit more B.C. doctors and nurses to help track the spread of flu strains this year and monitor the effectiveness of this year’s vaccine.

Just Posted

The theme for this year’s Fraser Valley Regional Library Summer Reading Club is “Crack the Case” and Katie Burns, community librarian at the Chilliwack Library, is encouraging people of all ages to sign up. She is seen here at the Chilliwack Library on Friday, June 18, 2021. (Jenna Hauck/ Chilliwack Progress)
Crack the case, read, win prizes with FVRL Summer Reading Club

‘Immerse yourself in other worlds and have a bit of fun while you do it,’ says Chilliwack librarian

Cpl. Scott MacLeod and Police Service Dog Jago. Jago was killed in the line of duty on Thursday, June 17. (RCMP)
Abbotsford police, RCMP grieve 4-year-old service dog killed in line of duty

Jago killed by armed suspect during ‘high-risk’ incident in Alberta

Kalyn Head, seen here on June 4, 2021, will be running 100 kilometres for her “birthday marathon” fundraiser on July 23. (Jenna Hauck/ Chilliwack Progress)
Woman’s 100-km birthday marathon from Chilliwack to Abbotsford will benefit Special Olympics B.C.

Kalyn Head hopes run raises awareness, advocates for inclusion of people with intellectual disabilities

Dancers from the Sts’ailes First Nation perform the eagle dance at a welcome banner dedication ceremony on Thursday, June 10. “Ey Swayel” is a Halq̓eméylem term translated as ‘a good day.’ (Adam Louis/Observer)
VIDEO: ‘A good day’ for Agassiz school as Sts’ailes welcome banner is dedicated

Banner hangs above the school’s entrance, welcoming students, staff and visitors

Missing Abbotsford man Adam Hobbs was found deceased on Thursday evening (June 17).
Body of missing Abbotsford man Adam Hobbs found

Hobbs was reported missing Monday after leaving his job site in Langley

Marco Mendicino, Minister of Immigration, Refugees and Citizenship during a press conference in Ottawa on Thursday, May 13, 2021. THE CANADIAN PRESS/Sean Kilpatrick
Canada to welcome 45,000 refugees this year, says immigration minister

Canada plans to increase persons admitted from 23,500 to 45,000 and expedite permanent residency applications

A police pursuit involving Abbotsford Police ended in Langley Saturday night, June 20. (Black Press Media file)
Abbotsford Police pursuit ends in Langley with guns drawn

One person arrested, witnesses say an officer may have been hurt in collision with suspect vehicle

(file)
Pedestrian hit by police vehicle in Langley

Injuries described as serious, requiring surgery

Barbara Violo, pharmacist and owner of The Junction Chemist Pharmacy, draws up a dose behind vials of both Pfizer-BioNTech and Oxford-AstraZeneca COVID-19 vaccines on the counter, in Toronto, Friday, June 18, 2021. An independent vaccine tracker website founded by a University of Saskatchewan student says just over 20 per cent of eligible Canadians — those 12 years old and above — are now fully vaccinated. THE CANADIAN PRESS/Nathan Denette
At least 20% of eligible Canadians fully vaccinated, 75% with one dose: data

Earlier projections for reopening at this milestone didn’t include Delta variant

This undated file photo provided by Ernie Carswell & Partners shows the home featured in the opening and closing scenes of The Brady Bunch in Los Angeles. Do you know the occupation of Mike Brady, the father in this show about a blended family? (Anthony Barcelo/Ernie Carswell & Partners via AP, File)
QUIZ: A celebration of dad on Father’s Day

How much do you know about famous fathers?

Emily Steele holds up a collage of her son, 16-year-old Elijah-Iain Beauregard who was stabbed and killed in June 2019, outside of Kelowna Law Courts on June 18. (Aaron Hemens/Capital News)
Kelowna woman who fatally stabbed teen facing up to 1.5 years of jail time

Her jail sentence would be followed by an additional one to 1.5 years of supervision

The George Road wildfire near Lytton, B.C., has grown to 250 hectares. (BC Wildfire Service)
B.C. drone sighting halts helicopters fighting 250 hectares of wildfire

‘If a drone collides with firefighting aircraft the consequences could be deadly,’ says BC Wildfire Service

A dose of the Pfizer-BioNTech COVID-19 vaccine is pictured at a vaccination site in Vancouver Thursday, March 11, 2021. THE CANADIAN PRESS/Jonathan Hayward
NACI advice to mix vaccines gets varied reaction from AstraZeneca double-dosers

NACI recommends an mRNA vaccine for all Canadians receiving a second dose of a COVID-19 vaccine

A aerial view shows the debris going into Quesnel Lake caused by a tailings pond breach near the town of Likely, B.C., Tuesday, Aug. 5, 2014. THE CANADIAN PRESS/Jonathan Hayward
Updated tailings code after Mount Polley an improvement: B.C. mines auditor

British Columbia’s chief auditor of mines has found changes to the province’s requirements for tailings storage facilities

Most Read