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

Jill Mackenzie carefully replaces books on the shelves at the Houston Public Library. (Angelique Houlihan photo)
District approves annual library grant

Craft kits featured for summer reading club

The tradition of Houston Christian School grads giving Bibles to incoming kindergarten students will take place this year, but outdoors and in a modified fashion. (File photo)
Houston Christian School grad day is June 24

Grads themselves have set tone for the day, says teacher

Scott Richmond will be starting as the new vice principal for HSS and TSE. (Submitted/Houston Today)
Houston gets a new vice principal

Scott Richmond takes over from Dwayne Anderson who moved to Smithers

A Pacific Salmon Foundation grant of $3,000 is going towards the tree plantations. (Cindy Verbeek photo/Houston Today)
550 trees planted in Houston through A Rocha

Houston Christian School students and volunteers help with the tree planting

Currently the Houston station has 16 paramedics, two ambulances and one community paramedic vehicle. (File photo)
Retirement of longtime paramedics worries Houston community

“No loss of service,” assures BC Emergency Health Services

A small pod of Pacific white-sided dolphins pass by close to shore in Campbell River June 16, 2021. Still capture from video courtesy of Kimberly Hart
VIDEO: Dolphin sunset captured from Vancouver Island shore

Spectacular setting for view of travelling pod of Pacific white-sided dolphins

Police are asking for public assistance in locating Anthony Graham who has been charged with the murders of Kamloops brothers Carlo and Erick Fryer. (RCMP photo)
2 charged, suspect at large in killings of B.C. brothers linked to gang activity: RCMP

Kamloops brothers Erick and Carlo Fryer were found deceased in May on a remote Okanagan road

Albert Health Minister Tyler Shandro and Alberta Premier Jason Kenney unveil an opening sign after speaking about the Open for Summer Plan and next steps in the COVID-19 vaccine rollout, in Edmonton, Friday, June 18, 2021. THE CANADIAN PRESS/Jason Franson
Alberta 1st province in Canada to lift all COVID-19 public health restrictions

70.2% of eligible citizens 12 and older in the province have received a dose of the vaccine

Fraser Health registered nurse Ramn Manan draws a dose of the Pfizer COVID-19 vaccine into a syringe at a walk-up vaccination clinic at Bear Creek Park, in Surrey, B.C., on Monday, May 17, 2021. THE CANADIAN PRESS/Darryl Dyck
‘Honour our fathers’ with COVID-19 vaccine protection, B.C. urges

109 new cases Friday, 75 per cent of 12 and up immunized

(Paul Henderson/ Chilliwack Progress)
Trutch Avenue in Chilliwack to be renamed to remove racist taint

New name to have Indigenous significance as Chilliwack takes new step toward reconciliation

Canadian Prime Minister Justin Trudeau is seen during a joint news conference following the EU-Canada Summit, in Brussels, Belgium, Tuesday June 15, 2021. Trudeau says Canada is on track now to have 68 million doses delivered by the end of July, which is more than enough to fully vaccinate all 33.2 million Canadians over the age of 12. THE CANADIAN PRESS/Adrian Wyld
Vaccine deliveries enough to fully vaccinate all eligible Canadians by end of July

Three in four eligible Canadians now have their first dose, nearly one in five fully vaccinated.

Chief Public Health Officer Theresa Tam listens to a question during a news conference, in Ottawa, Tuesday, Jan. 12, 2021. The number of confirmed COVID-19 cases attributed to the highly contagious Delta variant grew in Canada this week. THE CANADIAN PRESS/Adrian Wyld
Canada’s public health agency reports spike in confirmed cases of Delta variant

More than 2,000 cases of the variant confirmed across all 10 provinces and in one territory

Bella Bella is on B.C.’s Central Coast, accessible only by air and ocean. (Tom Fletcher/Black Press)
B.C. provides $22 million for Heiltsuk development on Central Coast

Elders care home project, tourism, lumber mill supported

Most Read