Navigation Links
Current Flu Season Worst in 4 Years
Date:4/17/2008

Vaccine wasn't a good match for circulating viruses, CDC says

THURSDAY, April 17 (HealthDay News) -- The current U.S. flu season has been the worst in four years, due, in part, to a vaccine that was not a good match for certain circulating strains of flu virus, U.S. health officials said Thursday.

For strains of influenza A (H3N2) -- the most prevalent virus during the 2007-08 season, the vaccine was 58 percent effective. But it was 100 percent ineffective against influenza B infections, leaving an overall vaccine success rate of about 44 percent, according to the U.S. Centers for Disease Control and Prevention.

"Most of the circulating influenza viruses this season have been less than optimally matched to the viruses in the vaccine," Dr. Dan Jernigan, deputy director of CDC's Influenza Division, said during a teleconference. "However, the vaccine did provide substantial protection against the predominant influenza virus circulating this season -- the H3N2 influenza A virus. Those people vaccinated were 58 percent less likely to have H3N2 infection than those not vaccinated."

The CDC researchers realized that two of the three circulating strains of flu this season did not match the strains contained in the vaccine, based on results of a study done in Marshfield, Wisc.

The CDC began working with the Marshfield Clinic in central Wisconsin to gauge the effectiveness of influenza vaccines during the flu season. Almost all people in Marshfield receive their health care from the clinic, according to a report in the April 18 issue of the CDC's Morbidity and Mortality Weekly Report.

This flu season, Type A H3N2 Brisbane strain has caused most of the illnesses but was not in the vaccine. The influenza A Florida strain, also not in the vaccine, has also caused sickness.

Jernigan noted that while this season's flu vaccine wasn't perfect, this year's results support getting vaccinated, even in years when the vaccine match is less than optimal.

"Although influenza A viruses have predominated this season, the most recently isolated viruses are influenza B viruses," Jernigan said. This year's vaccine is ineffective against influenza B viruses, he said.

Although the overall effectiveness of this year's vaccine was 44 percent, it has been higher in some years and lower in others, Jernigan said. "In the last 20 seasons, 16 have had good matches, and there have been four that were less than optimal matches," he said.

During the 1997-98 flu season, the vaccine's effectiveness was essentially zero, Jernigan said, adding that was the first year the Type A H3N2 influenza virus appeared.

In some years, the flu vaccine has had an effectiveness level of 70 percent, Jernigan said.

During the current flu season, the number of deaths peaked at 9.1 percent of all reported deaths, Jernigan said. "The number of deaths exceeded the epidemic threshold for 13 consecutive weeks," he said.

There were 66 flu-related deaths of children, 56 of whom weren't vaccinated, were improperly vaccinated or were too young to be vaccinated, Jernigan said.

During the 2003-04 season, deaths peaked at more than 10 percent and remained above the epidemic threshold for nine weeks, Jernigan said.

Each flu season, there are three different strains of influenza virus circulating. Different strains appear at different times, and different strains predominate, Jernigan explained. In addition, each of the three strains can respond differently to the flu vaccine.

It is this fluid flu picture that necessitates changing the vaccine from year to year, Jernigan said.

Since it requires almost a year to prepare the vaccine, decisions about the strains to include in the vaccine are often an educated guess.

But a study published in the April 17 issue of the journal Science could eliminate much of that guess work. Researchers reported that flu viruses originate in East Asia and Southeast Asia, and it takes about eight to nine months before these new viruses reach western Europe and North America.

Jernigan said the CDC is currently involved in promoting better surveillance of emerging flu viruses in East Asia and Southeast Asia. The hope is that these surveillance efforts will lead to more effective and better-matched vaccines.

According to the CDC, each year from 5 percent to 20 percent of the U.S. population gets the flu. More than 200,000 people are hospitalized from flu complications, and about 36,000 people die from the disease. Some people, such as older people, young children, and people with certain health conditions, are at high risk for serious flu complications.

More information

To learn more about the flu, visit the U.S. Centers for Disease Control and Prevention.



SOURCES: April 17, 2008, teleconference with Dan Jernigan, M.D., deputy director, Influenza Division, U.S. Centers for Disease Control and Prevention, Atlanta; April 18, 2008, CDC's Morbidity and Mortality Weekly Report


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Law Offices of Howard G. Smith Announces Investigation on Behalf of Current and Former Employees of Inverness Medical Innovations, Inc. Who Invested in the Inverness Medical Innovations, Inc. Employee Savings Plan
2. Keith Denner Extends Current Technologys Chairman and CEO Options
3. Law Offices of Howard G. Smith Announces Investigation on Behalf of Current and Former Employees of Merck & Co., Inc. Who Invested in the Merck & Co., Inc. Employee Savings and Security Plan
4. Law Offices of Howard G. Smith Announces Investigation on Behalf of Current and Former Employees of WellPoint, Inc. Who Invested in the WellPoint Retirement Savings Plan
5. China Bionanometer Industries (CBIU) Describes their Current Production Capacity and Product Lines
6. One-Third of U.S. Primary Care Physicians and Cardiologists Do Not Currently Prescribe Treatment to Meet HDL Cholesterol Targets as Recommended By National Guidelines
7. Current and Emerging Therapies Have No Advantage Over Pfizers Lyrica in Their Effect on Patients Quality of Life in the Treatment of Diabetic Neuropathy
8. Recurrent low-grade carcinoma of the ovary less responsive to chemo than more common ovarian cancers
9. U of Minnesota study finds thalidomide shows promise for treatment of recurrent ovarian cancer
10. Current Blood Sugar Control Test Results Inaccurate
11. Wild Childs Quit Nits Offers a Safe, Natural Alternative to Current Toxic Head Lice Products
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Current Flu Season Worst in 4 Years
(Date:1/17/2017)... CO (PRWEB) , ... January 17, 2017 , ... ... protection and financial planning assistance to families and business professionals throughout central Colorado, ... to regional homeless families. , The Aurora Warms The Night organization is committed ...
(Date:1/17/2017)... ... January 17, 2017 , ... Physicians Education Review®, LCC ... keynote speaker for the 34th Annual Miami Breast Cancer Conference®, on March 9-12, ... president, Phil Talamo, said, “We are delighted to have Sandra Lee join us ...
(Date:1/17/2017)... TX (PRWEB) , ... January 17, 2017 , ... Today, ... USA Wrestling announced a new agreement as part of a long-term extension ... December 2024 and includes the airing of some of the sport’s premier events exclusively ...
(Date:1/16/2017)... ... January 16, 2017 , ... California Southern University has named Dr. ... CalSouthern’s Board of Trustees and as a core faculty member, teaching master’s and doctoral ... professor of psychology at Pepperdine University, where he earned his Doctor of Psychology degree ...
(Date:1/16/2017)... ... January 16, 2017 , ... Anybody who may be looking for a substance ... released by Serenity Recovery, a holistic treatment center for addiction located in Marne, MI. ... and testimonials from patients and staff that visited the 2016 Recovery Palooza support event ...
Breaking Medicine News(10 mins):
(Date:1/17/2017)... 17, 2017 Research and Markets has ... 2017 - 2024" report to their offering. ... This new report revisits the ... that was issued in May of 2015. Self-healing is an area ... previous analysis we projected a market potential of $2.7 billion ($US) ...
(Date:1/17/2017)... Management to Discuss Acquisition of ... KIT-302 Development On Track For An NDA ... Q1 2017   ... Holdings Ltd. (NASDAQ: KTOV ; TASE: KTOV), an innovative biopharmaceutical company, ... rd at 8:30am Eastern Time to discuss the recent acquisition of a ...
(Date:1/17/2017)... 17, 2017  Edwards Lifesciences Corporation (NYSE: ... structural heart disease and critical care monitoring, plans to ... 31, 2016 after the market closes on Wednesday, February ... 5:00 p.m. ET that day to discuss those results. ... (877) 407-8037 or (201) 689-8037.  For 72 hours following ...
Breaking Medicine Technology: