Tracking the next pandemic: Avian Flu Talk |
Two Strains of Seasonal Flu May Not Match Vaccine. |
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jdljr1
Admin Group Joined: June 05 2006 Location: United States Status: Offline Points: 1621 |
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Posted: September 27 2014 at 3:13am |
This new article from CIDRAP could be bad news for us facing the current Northern Hemisphere flu season-the vaccines already manufatured and starting to be given here may already be a mismatch with regards to the H3 and B strains. Just great. At least they will be changed in time for you down-under. For next summer, that is. The most likely scenario us Northerners will face is a reduction in flu vaccine efficacy, never great anyway, from perhaps 70% to only 50%. Just peachy. John L.
http://www.cidrap.umn.edu/news-perspective/2014/09/who-switch-2-3-strains-2015-flu-vaccine
WHO: Switch 2 of 3 strains in 2015 flu vaccineFiled Under: | Sep 26, 2014 1xpert / iStock Two strains for next year's Southern Hemisphere's flu vaccine will be different. The World Health Organization (WHO) yesterday recommended changing two of the three strains in trivalent influenza vaccines for use next year in the Southern Hemisphere, because of signs that changes in circulating strains have made them less well matched to the current vaccine. The WHO called for switching the A/H3N2 and B strains in trivalent vaccines. For quadrivalent (four-strain) vaccines, which contain two B strains, the agency recommended no change in the second B component. The A/H1N1 strain in the vaccine also should stay the same, the WHO said. "Increasing proportions of the recently circulating A(H3N2) and influenza B Yamagata-lineage viruses have undergone antigenic drift since the last vaccine recommendation," the agency said in a question-and-answer statement accompanying the vaccine recommendation. Because of the time it takes to prepare vaccine viruses and grow them in eggs or mammalian cell cultures, the WHO recommends the vaccine strains in September for the following year's Southern Hemisphere flu season and in February for the Northern Hemisphere season. The WHO recommends the following for trivalent vaccines:
For quadrivalent vaccines, the agency recommended using the same strain as in the current Northern Hemisphere vaccine for the second B strain: B/Brisbane/60/2008, which belongs to the Victoria lineage. Quadrivalent vaccines have been developed in recent years because of the difficulty of predicting which B lineage, Victoria or Yamagata, will dominate in any season. Yamagata viruses have remained dominant over Victoria strains over the past 8 months, the WHO said. Antigenic driftTo assess the match between flu vaccines and circulating flu viruses, WHO laboratories take serum from vaccinated ferrets and humans and examine how well the antibodies in the serum react with circulating viruses. Most recently isolated H3N2 viruses were antigenically distinguishable from the H3N2 virus in the current Northern Hemisphere vaccine, called A/Texas/50/2012, and more closely matched A/Switzerland/9715293/2013, the WHO said. "Current vaccines containing A/Texas/50/2012 antigens induced antibodies in humans that reacted less well to A(H3N2) clade 3C.3a viruses," the agency said. The strains in the current Northern Hemisphere vaccine are the same as in last year's version and in the 2014 Southern Hemisphere vaccine. Low drug resistanceIn a note on drug resistance, the WHO report said the "vast majority" of H3N2 and B isolates analyzed in recent months were susceptible to available antivirals, including oseltamivir (Tamiflu), zanamivir (Relenza), peramivir (sold in Japan as Rapiacta), and laninamivir (sold in Japan as Inavir). It said most H1N1 viruses also were susceptible to the drugs, but a small proportion of tested H1N1 isolates showed resistance. In Japan, 2.7% of isolates showed resistance to oseltamivir and peramivir. |
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John L
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Albert
Admin Joined: April 24 2006 Status: Offline Points: 47746 |
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It may not be worth getting, but who knows. I've actually never had a flu shot in my life. No particular reason for not getting it, and I just usually fight my way through being sick, but I also haven't been sick in a few years. People tend to get sick just entering the clinic for the shot. If I had kids or exposed to them I would probably get it.
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jdljr1
Admin Group Joined: June 05 2006 Location: United States Status: Offline Points: 1621 |
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It shall also depend upon how one strain usually dominates, and which one shall this year? If the H1, best to have had the vaccine. But if H3 or B Yamagata dominate, the vaccine may be of little use.
Recently also most parts of Australia were H!, but a minority of areas, it was H3. So what wil I do? I shall get the vaccine, but with now limited expectations.
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John L
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drumfish
Adviser Group Joined: September 08 2014 Status: Offline Points: 3115 |
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I just got my shot 2 days ago. I figure it can't hurt and will probably help. So I get one every year. I have always wondered why they don't put more in them. With insurance its free, I would pay $20 out of pocket for a second shot if offered if it would cover extra strains every year.
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hachiban08
Senior Moderator Joined: December 06 2007 Location: California, USA Status: Offline Points: 15627 |
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I got my shot yesterday, before my PT appt. They only had a few left for the day, because today is their Flu Shot Kickoff thing at Kaiser and expect high wait times. Hopefully it works, if not, it was worth a try.
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Be prepared! It may be time....^_^v
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onefluover
Admin Group Joined: April 21 2013 Location: Death Valleyish Status: Offline Points: 20151 |
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It's been pretty much the same with me. Never had one that I'm aware of. My son gets them but then he still seems to get sick with something literally every two or three months. One time I'm sure I picked up something while getting him his shot. |
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"And then there were none."
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