The strain information is here: http://www.cdc.gov/flu/about/qa/vaccine-selection.htmLewis591 wrote:Interesting news. the FDA has just approved a brand-new vaccine for 2012-2013, which helps to vaccinate three various flu strains. Six companies will be manufacturing the injections. Anybody that has health-related, or immune deficiencies, should check to see if they can get vaccinated as soon as possible.
TL;DR - seasonal flu shot contains three strains, one of which is an H1N1. The shot is an inactivated ("killed") vaccine which means you can't get the flu from it, and you can't shed the attenuated vaccine strain. This only really matters if you've got a weak immune system, or spend time around someone who does.
On that note, most people who get infected with flu will be shedding virus for 24-48 hours before symptoms appear. Also, up to 20% of adult infections are sub-clinical, meaning you might feel a little lousy but won't know you have the flu. You'll still be shedding all over the place.
For anybody that hasn't been following the news, the excess mortality from H1N1 peaked at ~6000 per year in the US (don't recall the exact numbers, but I can look it up on the pubmeds if anyone is really curious). As we all know by now, it wasn't the apocalyptic 1918-style pandemic, but it was still a very bad bug. The institution I'm at was at max capacity for ventilators on at least one occasion, and I know it wasn't the only hospital that had that problem.
The four highest risk groups were: young, very old, pregnant, and significantly overweight/obese. Pandemic flu (H1N1) is really brutal on pregnant women, not only inflicting higher mortality, but also increasing the risk of miscarriage*, stillbirth, and pre-term/low birth-weight delivery by up to 4x. There have been a number of studies showing the vaccine is safe for pregnant women, and there is some carryover protection for the baby via maternal trans-placental antibody transfer. Kind of a two-fer.
Also, at least one good-sized study showed flu vaccination has a protective effect out to ~1 year against severe cardiovascular events. Most likely explanation... systemic inflammation is pro-thrombotic --> pro-thrombotic state leads to clotting (especially in those with underlying disease) --> clot gets thrown --> bad things happen (i.e. stroke).
Please get your flu shot. Unless you hate pregnant women. And grandma. And kids.
* This appears to have been the case with the 1918 pandemic strain, which caused up to 10% of pregnant women who survived infection to miscarry, so not a new phenomenon. Why some people are still telling pregnant women not to get vaccinated is beyond me. Why some healthcare facilities don't mandate employee vaccination is also beyond me.