Flu vaccine was disappointing vs. some strains last season

Flu vaccine was disappointing vs. some strains last season

Flu vaccine was disappointing vs. some strains last season

NEW YORK — The flu vaccine did a disappointing job last winter in the U.S., and officials worry that might be a bad sign for the fall.

Flu vaccines had been about 60% effective against the type of flu that caused the most lab-confirmed illnesses last winter, but last season’s vaccine was only about half that good, according to study results reported Wednesday.

Against another major type of flu, vaccines have already been only around 30% effective.

The new results may be a sign of shrinking effectiveness against a number of strains, and “that’s concerning,” said Brendan Flannery, who oversees the U.S. Centers for Disease Control and Prevention’s system for evaluating the vaccine.

The results come as health officials are gearing up for a critically important flu vaccination campaign, with a record 180 million doses being prepared. U.S. health officials fear a second wave of coronavirus infections, and reducing flu illnesses could help reduce patient traffic if COVID-19 causes doctors’ offices and hospitals to become overwhelmed.

CDC numbers indicate that last winter’s flu season caused somewhere in the neighbourhood of 22 million medical visits, 575,000 hospitalizations and likely more than 40,000 deaths.

Vaccines against many infectious diseases aren’t considered successful unless they work at least 90% of the time, but flu is particularly challenging, partly because the virus can quickly change. Overall, flu vaccine effectiveness averages around 40%. Last season’s was 39% overall.

Last winter’s flu season featured two waves, each dominated by a different virus. Both flu bugs are considered dangerous to children, and it was a very bad flu season for kids.

Health officials reported 185 U.S. flu deaths in children this past flu season, the second highest total in a decade. And officials believe that because of reporting lags, additional cases may still come in.

Most of the children who died were not vaccinated. But how well the vaccine performs in kids remains a large concern.

A Type B flu strain ended up causing most early season illnesses and the bulk of illnesses in children over the entire winter, Flannery said. The vaccine was about 39% effective against that strain in children.

But the vaccine did an awful job against the Type A H1N1 strain that caused the second wave of illnesses. Protection was so low in kids ages 6 months to 17 years that — statistically speaking — it couldn’t be counted as working at all.

The vaccine’s performance was down in adults, too, and health officials don’t know exactly why. It may be due to changes in the virus, Flannery said.

Health officials have changed the components of what’s in the flu shot this year, in what they hope will be a better match against whatever flu strains circulate this fall and winter, he said.

The findings are drawn from a study of more than 2,700 people in five states with lab-confirmed flu infections, and presents estimates of vaccine effective in preventing flu illness severe enough to send a patient to a doctor’s office. They were presented during an online meeting of the Advisory Committee of Immunization Practices, an expert panel which the CDC looks to before making vaccination recommendations to U.S. doctors.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Mike Stobbe, The Associated Press

vaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Alberta Chief Medical Officer of Health Dr. Deena Hinshaw
Alberta eases some COVID-19 restrictions

Salons, barbershops and other personal and wellness services will be open by appointment only

File Photo
‘You took away some real joy.’ Sylvan Lake Winter Village turned off after vandalism

Sometime during the night of Jan, 12 the light display at the pier was vandalized and damaged

(Black Press file photo)
Sylvan Lake man charged with fraud totalling more than $100,000

Sylvan Lake RCMP have been investigating two companies owned by the same man since June 2019

Environment Canada issued a wind warning for parts of central Alberta on Jan. 13, 2021. (Black Press file photo)
Wind warning issued for central Alberta

Environment Canada said strong northwesterly winds will develop in the morning and weaken in the evening

Lesser Slave Lake UCP MLA Pat Rehn. (Facebook)
Kenney kicks Pat Rehn out of UCP caucus after municipal complaints

Rehn had been criticized by municipal leaders in his constituency

blessing
Bentley Blessing Pantry continues to faithfully serve the community

‘We just wanted to make everyone aware that we are still here to serve you throughout this coming year.’

A Suncor logo is shown at the company’s annual meeting in Calgary on May 2, 2019. A worker is missing after a dozer broke through ice on an inactive Suncor tailings pond in northern Alberta.THE CANADIAN PRESS/Jeff McIntosh
Worker missing after dozer breaks through frozen tailings pond in northern Alberta

The worker was an employee of Christina River Construction

A health-care worker prepares a dose of the Pfizer-BioNTech COVID-19 vaccine at a UHN COVID-19 vaccine clinic in Toronto on Thursday, January 7, 2021. THE CANADIAN PRESS/Nathan Denette
COVID clarity: Feds say 42-day gap for 2-dose vaccines OK as provinces race to immunity

‘Realities on the ground’ means that provinces, territories will have difficult choices to make

(Pixabay photo)
Alberta surgeon who hung a noose in a hospital found guilty of unprofessional conduct

College of Physicians and Surgeons says sanctions will be determined at a later hearing

A health-care worker prepares a dose of the Pfizer-BioNTech COVID-19 vaccine at a vaccine clinic in Toronto on Thursday, January 7, 2021. The professional group for emergency doctors in Canada wants more transparency about COVID-19 vaccine distribution. THE CANADIAN PRESS/Nathan Denette
Canadian emergency doctors call for greater transparency on vaccine rollout

Many doctors don’t know when they will be vaccinated and the association says that needs to change

Vancouver Canucks’ Brock Boeser (6) and Elias Pettersson (40) celebrate a goal against the Edmonton Oilers during third period NHL action in Edmonton on Wednesday, Jan. 13, 2021. THE CANADIAN PRESS/Dale MacMillan
Boeser scores 2, Vancouver Canucks dump Edmonton 5-3 in NHL season opener

Rookie Nils Hoglander nets first career goal in win over Oilers

Most Read