Side effects, when? 1. Pneumonia is an immediate concern, few days to few weeks at most. Flumist-virus is engineered to grow only in the "cold" nasal mucosa enviroment, not in the "hot" lungs. It has not been a problem in children age 5 to 18, and large trials of couple of thousands were done AND season to season follow up protection proven (at least 1 year follow up).
In the elderly, past 65, some how the virus had INDEED produced pneumonia as a side effect, and usually within days of administration, maybe the elderly do have "cool" lungs.
2. Another concern is the mixing mingling and exchange of properties among the Fluvist-virus and the wild virus variants of the season, IF flumist is given inadvertenly (very easy to do) to a subject with an ongoing wild virus infection it could theoretically form a new vaccine-wild virus strain with worst charasteristics than the parent strains, this I read a post in yahoo that seems reasonable BUT BIG CAVEAT I do not know if possible or real or any evidence of it (but certainly not a wild theory) and IF these were true it is a very complex problem to solve.
By the reading of some of the deposition it does not look like imposible solutions are asked for to Aviron to solve, but more clinical trials, more expense and more delay, so the stock is tanking accordingly.
Aviron was not smart in looking for vaccination of less than 5 year old children, it is more difficult to do everything in that group regarding safety. BUT they are a nice captive population once a vaccine is approved for that group the market penetration quickly goes to 90% (and the lure of mucho money quick), cause they are already visiting the pediatrician and being vaccinated all the time.
The last live virus vaccine approved was the Rotashield (against rotavirus diarrhea disease) and there was a known "low" risk for severe bowel complication (intussucepstion, or the sausage bowel) that was confirmed much higher during marketing (at low penetration rates) and cause the removal of the vaccines and an embarrasment to the FDA.
No one gets Asthma disease from Influenza virus per se, it complicates Asthma and can contribute to the origins (not proven) the vaccine concern is not that it will produce asthma (nil evidence so far) but that it will exacerbate Asthma. If it can give pneumonia, it can exacerbate asthma,like the wild disease does and one of the main reason to vaccinate is to decrease these chances. If proven not to give pneumonia then it will not exacerbate asthma.
Now the remaining short term problem is: Will the FDA approved Flumist for the coming fall, even in a limited fashion, for use? over and despit the safety concerns of the Advisory comitte panel (FDA is not binded to follow the recommendations of the panel)? I strongly doubt that.
Bottom line, get your IM shot this year, and watch Aviron tank slowly toward the $15 range with luck, thanks to the almost half a bilion $ in cash and a cash rich AHP partner willing to keep supporting Flumist. |
