Flu Season: Vaccine Seems Good Match So Far

barbara

Pioneer Founding member
Good to know that they don't think this year's vaccine will be a flop like last year's. I didn't even bother to get a flu shot last year because of the fact that it was basically ineffective, especially for my age group. One nurse told me I should get one despite the problem because if I got the flu, I would end up in the hospital most likely, but I would probably be able to shave a day or two off the stay. Say what????


MedPage Today
by Joyce Frieden
News Editor, MedPage Today

Vaccine has been updated to better match the H3N2 strain

WASHINGTON -- Unlike last year, this year's flu vaccine seems to be tracking pretty well with the influenza viruses that are currently circulating, CDC director Tom Frieden, MD, MPH, said Thursday.

"The vaccine has been updated to better match the H3N2 strain," sometimes referred to as the Switzerland variant, Frieden said at a press briefing here sponsored by the National Foundation for Infectious Diseases. "What's spreading are three or four strains that match what's in the flu vaccine this year." A total of 171 million doses of the flu vaccine are available, with 40 million having been distributed so far, he said.

NFID medical director William Schaffner, MD, said that the last flu season "reinforced that every flu season is a unique experience ... Flu is fickle."
During most seasons, flu vaccines offer good protection against circulating viruses, he explained. "But last season was unusual. Not only did we have one strain of influenza that caused almost all of the reported flu cases, but it was different ... It had mutated; it was different than the strain that was represented in the vaccine."

"So far, as we track influenza viruses this year, the ones that are causing very early disease are exactly as was predicted, so looks to me as though [those who take] the vaccine will be well protected," said Schaffner, who is also a professor of preventive medicine and infectious diseases at Vanderbilt University School of Medicine, in Nashville, Tenn.

Although no influenza vaccine will prevent people from getting the flu 100% of the time, "the vaccine is usually about 50-60% effective -- not nearly as much as most major vaccines, but far more effective than anything else you can do to prevent the flu," Frieden said. And even though last year, the overall effectiveness was much lower -- and was only about 13% for the H3N2 strain -- "there are still benefits from flu vaccination even at that lower effectiveness," he added.

To see how well the flu vaccine is likely to work, U.S. researchers engage in global collaboration, working with countries all around the world to see what's spreading in the Southern Hemisphere, which is usually what spreads in the U.S. the following winter, Frieden explained. They also track flu trends in the U.S. during the summer.

This year, 199 specimens were analyzed; "of those, 118 were the H3N2 type that is closely related to this year's vaccine strain. Another 20 were the H1N1 still circulating from back in 2009, also very closely related to what's in the vaccine strain," said Frieden. "There were 61 influenza B strains that were evenly matched between two different strains that were included in the quadrivalent vaccine. All strains analyzed were susceptible to anti-virals oseltamivir [Tamiflu], zanamivir [Relenza], and peramivir [Rapivab]."

Frieden emphasized it was particularly important for healthcare workers to be vaccinated and to make sure all of their eligible patients were vaccinated. To prove his point, he got his own flu vaccination during the press conference. The CDC on Thursday also released results from an online survey of 1,914 healthcare providers which showed that overall, 77.3% of participants reported receiving an influenza vaccination during the 2014–15 season, similar to the 75.2% figure for the 2013-14 season.

Vaccination coverage was highest among healthcare providers working in hospitals (90.4%) and lowest among those working in long term care settings (63.9%), the survey found. In terms of occupation, pharmacists had the highest rate of vaccination (95.3%) while assistants and aides had the lowest (64.4%).

Panelists at the briefing also discussed the importance of pneumococcal vaccines, especially for patients 65 and older or those ages 19-64 with chronic illnesses such as diabetes and heart disease. "These vaccines work," said Schaffner, citing as proof a study that was published in last March in the New England Journal of Medicine analyzing the effectiveness of the conjugate vaccine in those 65 and older.

The study found that "there was a significant reduction in vaccine-type pneumococcal community-acquired pneumonia," he said, noting that the study was quite large and included 85,000 adults 65 and older with no prior pneumococcal vaccination history.

Panelist Kathleen Neuzil, MD, MPH, professor of medicine and director of the Center for Vaccine Development at the University of Maryland School of Medicine, in Baltimore, summed up the flu vaccine situation, saying, "The news is that more people are getting vaccinated, but far too few are getting vaccinated and we need to try to improve that. Lot of gains can be made in the young and middle-aged adult population."

Editor's note: Article author Joyce Frieden is a second cousin to CDC director Tom Frieden. She did not interview him for this story and speaks with him only occasionally.
 
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