NOT OUT OF THE WOODS YET: Brayden Yee, 5, of Shoreline, Washington, receives a dose of FluMist from a Bartell Drugs pharmacist. Photo:TNS
CDC officials recently announced that the 2014-2015 vaccine is a
poor match for about half of the H3N2 viruses that appear to be the
dominant strain already spreading this season, writes Jonel Aleccia
Nancy Dragun wanted to ward off flu this year, so she got her family vaccinated early, a shot for herself and doses of the FluMist nasal spray for her two boys, ages 9 and 11.
“I trust the experts, I guess, and my paediatricians have always recommended it,” said Dragun, 42, who works at the University of Washington.
But Dragun said she’s disturbed at new evidence showing this year’s vaccine — both the FluMist spray and the seasonal shots — likely won’t protect very well against targeted flu viruses. In the case of FluMist, there are problems with effectiveness in two of the three or four flu strains it’s formulated to hit.
“I’m starting to wonder if I should have done that,” Dragun said. “It’s a little bit nerve-wracking, for sure.”
At the start of what may be a bad flu season, health officials are scrambling to reassure the public that even though this year’s vaccine has problems, it’s still the best way to prevent potentially deadly flu infections.
“The flu is a very wily and cagey virus,” said Dr Don Shifrin, a Bellevue, Washington, paediatrician. “Every year we try to play whack-a-mole with the flu virus. Some years we do better than others, but we’re still in the game.”
A report released in November by the federal Centers for Disease Control and Prevention found that FluMist offered “no measurable effectiveness” against one virus, the H1N1 swine flu, among children last year. Because the vaccine hasn’t changed, the same results may occur this year, health officials said.
Then CDC officials recently announced that the 2014-2015 vaccine is a poor match for about half of the H3N2 viruses that appear to be the dominant strain already spreading this season.
“Flu is unpredictable, but what we’ve seen thus far is of concern,” CDC Director Dr Tom Frieden told news reporters.
This could be a worse-than-normal year for flu, Frieden added, because seasons in which H3 viruses dominate typically cause more illnesses and deaths than seasons in which H1 viruses are common.
CDC officials also warned doctors about the problem, urging them — and consumers — to seek antiviral drugs such as Tamiflu and Relenza at the first sign of flu, especially for people particularly vulnerable to infection.
The antiviral drugs don’t stop flu, but they may shorten the intensity and duration of the illness, experts said.
The flu-vaccine problems are bad news for health officials, who recommend that everyone older than six months get shots or sprays. Only about 42 percent of adults and less than 60 percent of kids and teens got inoculated for flu last year, according to the CDC.
In a good year, flu vaccine is about 50 to 70 percent effective at preventing illness, experts estimate. In a bad year, more of those inoculated get sick anyway.
In 2007-2008, when there was a mismatch between vaccine and virus, efficacy dropped to just above 40 percent. Shifrin said he worries that might prompt some people to skip the shots this year — and in the future.
“It’s very easy to scare people,” he said. “We don’t want to put out the message that the flu vaccine doesn’t work.”
The flu season has just started, health records show.
About 94 percent of more than 13,000 samples tested so far by the CDC are the dominant H3N2 subtype of flu, about 6 percent are the B strain, and almost none were the H1N1 swine flu, which descended from the 2009 pandemic strain, according to new flu figures released last week.
But more than half of the H3 subtypes — or 58 percent of the samples — are a new H3 strain that has “drifted,” or changed from the type targeted by this year’s flu vaccine. As a result, the vaccine likely offers poor protection against that strain, Frieden said.
That subtype first showed up in March overseas, but it wasn’t seen in large numbers in the US until September. Because it takes about four months to manufacture a flu vaccine, it’s too late to make a change, Frieden added. So far this year, about 150 million doses of flu vaccine have been released.
The problem with FluMist is different. Scientists still don’t know why the vaccine failed almost completely to protect against the H1N1 swine-flu strain last year, particularly in the youngest patients.
“This was very surprising,” said Mike Jackson, a scientific investigator at Group Health Research Institute in Seattle, one of five sites across the country that routinely conduct vaccine-effectiveness checks for the CDC. “It’s really quite different from the way this specific vaccine performed in the last couple years.”
In fact, CDC officials were so confident about the nasal spray, which uses a live but weakened virus, that in June they recommended that it be the first choice for kids ages 2 to 8 for the 2014-2015 season.
News about problems with the vaccines is surprising and concerning for parents like Dragun.
“As a mother, my first priority is to protect my kids, but I don’t want to put anything additional into them if it’s not going to protect them,” she said.
Health experts say they hope parents take a wider view, that vaccines still offer important defense against flu, which has been linked to the deaths of five children nationally already this season.
“What I would tell parents — and what I would tell my wife, who asked the question — is that the vaccines may have lower effectiveness, but they have some effectiveness,” said Dr Joe Bresee, the chief of epidemiology and prevention in the CDC’s flu branch. “I wouldn’t regret getting the vaccine and, moreover, I would say go out and get it.”
There’s some evidence that FluMist may actually protect better against so-called drifted strains, such as the new H3N2 virus. There’s almost no H1N1 circulating this year, so it’s still a good choice, Bresee said.
If kids already have received FluMist this year, they’re considered fully vaccinated, CDC officials said. It’s not recommended that they get a shot too, noted Dr Doug Opel, a paediatrician and bioethicist at Seattle Children’s.
No parent — or grandparent — should forgo flu vaccine for themselves or their kids because of the reported problems, Opel said.
“Remember, each year, influenza causes more hospitalisations and deaths in the US than any other vaccine-preventable disease,” he said. The CDC estimates that flu causes 200,000 hospitalisations and anywhere between 3,000 and 48,000 deaths in the US in any given year. Most deaths are among people older than 65.
Despite her concerns about vaccine effectiveness, Dragun decided that she’s glad she and her boys are vaccinated. They’re pretty healthy kids, generally, and even if the vaccine doesn’t stop the flu, the illness may be shorter and less severe.
“I guess I come down on that side,” she said. “It’s better to have some protection than no protection.” — The Seattle Times/TNS