Got the swine flu vaccine. Now what?

November 5, 2009 12:10 AM

Just got the swine flu vaccine (shot) and I have some questions.

O.K., I got the shot, but there are some questions that I have:

1. Is there a second shot? No one at the clinic mentioned anything about second shot to me while I was there, but I read an article published in September about swine flu vaccine being in two parts. Is this still the case or outdated information.

2. How effective will this vaccine be? Found another article that said 75 percent effective. These do not sound like good odds, but the article was two months old as well. Any recent updates?

3. How long should it take before I can encounter someone with swine flu and not get it now that I have had the shot.

Maybe others of you have the same questions so I hope this helps you as well. Thanks.

posted by boots77 to health & fitness (15 comments total)

1) No. The vaccine being distributed now requires only a single dose for effectiveness. Unless you're a child: then you need a booster.

2) What does that mean? The effectiveness of drugs (and vaccines) is a statistical process based on individuals. It's not that you, personally, have a 75% chance of infection. It's that 75% of individuals who receive the vaccine and are exposed get ill. So, there's a 75% chance you're immune; and a 25% chance you're not immune.

3) I believe that it's about a week.

But, really, the thing that would contribute most to you not getting sick is washing your hands. Between the vaccine and washing your hands, your chances are pretty low for contracting a mild, not-especially-dangerous disease.

However, since you got the shot ahead of everybody else, I assume you must be in a high risk group--pregnant, a healthcare worker, or a child under the age of 24. So you should be taking extra precautions anyway.
posted by Netzapper at 12:31 AM on November 5, 2009

I'd like to point you to a few resources, so you can feel confident about the answers you receive to your question.

1. "The U.S. Food and Drug Administration (FDA) has approved the use of one dose of 2009 H1N1 flu vaccine for persons 10 years of age and older." US Center for Disease Control.

2. I can't find a soundbite-sized quote, because the answer is more complicated than that. The vaccine manufacturers include an insert with the vaccines. Part of the insert discusses the clinical studies they conducted, and the effectiveness of the vaccine during the studies. Please see the insert from one manufacturer, CSL, (PDF), starting on Line 295. This is posted on the FDA's website; the FDA also has the inserts from Novartis and Sanofi Pasteur (the other 2 manufacturers) and MedImmune, which is the manufacturer of the nasal spray vaccine.

3. "Influenza vaccines only become effective about 14 days after vaccination. Those infected shortly before (1 to 3 days) or shortly after immunization can still get the disease." World Health Organization.
posted by Houstonian at 2:03 AM on November 5, 2009

I'm pregnant and just got it last Friday. This is what I was told.

No, no need for a second shot.

It takes your body 7 to 14 days to build up immunity to H1N1 after getting the shot. So washing hands, etc. is still very important.

As Netzapper said above, the 75% number is based on population; not you personally. But since you might not have full immunity for about a week or two, you could still get it so still need to be careful. After that, likely you will be fine. (Based on your risk factors. Pregnant people seem to respond well to the vaccine. But someone who is immunosuppressed might have a bit more trouble, I'd imagine.)
posted by Bueller at 2:03 AM on November 5, 2009

75% effective means that you are 75% likely to be immune. Not 25%.
posted by chesty_a_arthur at 4:09 AM on November 5, 2009

The 75% number comes from studies of the seasonal flu vaccine, which is made from the three strains that are judged most likely to be of concern several months before the flue season. The H1N1 vaccine, being matched to the strain we know we're worried about, may be more effective:

"“Protection rate against artificial challenge with influenza A was 96% when vaccine and challenge viruses were homotypic. When the vaccine strain and challenges virus were heterotypic, protection ranged from 70-100%. Protection rate from infection during a homotypic epidemic was, retrospectively, 95%; while 50-87% protection from influenza illness was achieved during a heterotypic epidemic. In all instances, vaccinees experienced mild, mostly afebrile upper respiratory symptoms, unlike controls who had moderate to severe symptoms, often with fever. Infecting virus was shed more often by unvaccinated controls (PubMed)."
posted by molybdenumblue at 4:29 AM on November 5, 2009 [1 favorite]

I think what chesty_a_arthur's trying to say is that with 3:1 odds, you could sweep Vegas.

Also, you should have a look at the most recent findings on vaccine efficacy. It's really not a random chance. It's more that a certain proportion of the population simply isn't capable of responding, and that we have no way of identifying them, so it looks random.

What's more, my wife (who's a nurse) only managed to find one study related to infection rates (as opposed to antibody concentrations). She got it from the CDC website, which she'd like you to know is a thrilling source of factual information quite useful for answering these sorts of questions, as well as dispelling hysteria.

That particular study had the following results: out of 120 vaccinated patients, only 1 got the H1N1 flu. And that was reported only 8 days after vaccination, before antibodies were expected to be in sufficient concentration. 1 out of 120 is not 75% effective. It's, uh, 99.2% effective.

And, seriously, unless you're pregnant--which doesn't seem to be the case, as your history impliess you're a dude--this is just a fucking flu. Like the flu you had last year. Get some body aches, lie in bed, skip work, drink lots of ginger ale, eat saltines, swallow ibuprofen, vomit, go back to work in a week.

The only reason that H1N1 is such a problem is that young people don't have any antibodies for it--we haven't seen a similar flu since the 60's. So people my age are going to be getting it at a much higher rate than we normally get the flu. It's running rampant through colleges all across the country. The "public health issue" is that the emergency rooms get all clogged up with people demanding medical attention for their headaches, thereby preventing people who actually need medical attention from receiving it.

The regular flu kills at a rate of around 1-2%. If you aren't scared of the regular flu, you have no reason to be scared of this one.

Frankly, I'm kind of really goddamn pissed off that you got the vaccine if you're not immunocompromised--which I doubt, or they would have already answered all your questions. Like, hopping up and down mad. That's a dose that could have gone to a healthcare worker, and AIDS patient, or a pregnant woman. Maybe I'm not mad at you, but I'm mad at whoever gave you the dose.
posted by Netzapper at 4:39 AM on November 5, 2009 [3 favorites]

I have two kids at home right now, one recovering from H1N1, one currently battling it. My son was sick for 12 days with high fever (103-104 for more than a week) and bad cough, and was eventually hospitalized for respiratory distress after the high fever gave way to a secondary respiratory infection. My daughter got the intranasal vaccine at school the day after my son came home from the hospital. Seven days later -- before the vaccine had time to "take" -- she woke up with the spiking fever that was a hallmark of the start of her brother's illness. We started her on Tamiflu immediately, and that cut the high-fever portion of the course from 5 days to three; now she is in the low-fever, still coughing phase that for my son turned into respiratory distress, but I think due to starting the Tamiflu within 24 hours of onset her outcome will be better.

It's scary stuff. Having your kid zoned out with 104 is scary. Having your kid in the hospital is scary. Watching your seven year old turn gray and struggle to breathe is scary. I don't begrudge the OP getting the vaccine one bit.

As for the questions, as others have said, there's no second shot necessary, and it generally takes two weeks for the vaccine to be fully effective.
posted by mothershock at 5:32 AM on November 5, 2009 [3 favorites]

You should not consider yourself "immune" because you have received the vaccine. It may not be effective in you, and it is possible to be exposed to strains for which the vaccine does not protect (including other versions that arose after the manufacture of the vaccine). You should still take all the same precautions, avoiding the infected, washing your hands, etc.

Although I should note that hand washing is extremely important for countering the spread of disease generally, but influenza travels directly through the air, and some public health experts are questioning how effective hand washing is against it.

1 out of 120 is not 75% effective. It's, uh, 99.2% effective.

There's a reason the paper you cite did not use this figure—because it is misleading. It's unlikely that all the study participants were exposed to the virus, and without the vaccine, the other 119 people would not all have contracted it. It's like saying my MacGuffin is more than 99.2% effective at ridding the Scottish Highlands of lions.

The projected mortality rates as a proportion of the overall population are much higher than in typical seasonal influenza. This is mainly because more people are going to be infected—so far fatality rates as a proportion of infected cases seem to be comparable. But the fatality rates in young people in the initial outbreak were much higher than usual, leading to significant worries, and is one of the reasons why people under 24 are included in the "at risk" categories.

Also, this really, really isn't the place to express how "really goddamn pissed off" you are about who is getting the vaccine.
posted by grouse at 6:12 AM on November 5, 2009 [3 favorites]

Netzapper, the OP could have a child at home who is 6 months old, or have a pregnant wife, or be a sort of fake healthcare worker like myself. (Under MA law, since I work for a healthcare provider, I am supposed to get the H1N1 vaccine if my employer can make it available to me, even though I work with data and not patients. Now, I don't know any more than the average person about vaccines and immunity, so I would have any number of questions, even though I am technically a healthcare worker. They don't want me to get sick and then pass it on to my physician boss, and so forth.)

Maybe it was inappropriate and contrary to the CDC guidelines that the OP received the vaccine, but we definitely don't know that it is.
posted by teragram at 6:28 AM on November 5, 2009 [2 favorites]

Confusing the issue slightly is that you don't need a second swine flu vaccine shot - but if you want to lock in your immunity, you will need to get a seasonal flu (i.e. "regular flu") shot. These are freely available, and you won't have to jump through the same hoops you did for the swine flu vaccine.

I have heard that you should wait at least a week or two before getting the seasonal flu vaccine. But as with everything else, You Should Check With A Doctor On That.
posted by ErikaB at 8:23 AM on November 5, 2009

First, Mothershock, I'm so sorry to hear your kids are sick/in the hospital. I totally understand. With my son having 2 prior bronchiolitis episodes under 6 months old (and one hospital stay), I'm scrambling to find the shot and can't without a month out appointment.

Like the others said, you only need one for your age and you don't have to justify to us in getting one. DuPage County in IL let everyone and their brother stand in line without criteria. So it does happen.

There is no spacing for the seasonal flu shot. Our pediatrican said that if the timing and marketing weren't so rushed, the H1N1 strain (which includes avian too) would have been rolled into the regular flu shot. But given the mass panic and spread, they didn't have time.

You can get your regular flu shot whenever or space it if you feel more comfortable. Good luck and stay well.

For hand washing, yes it helps for any illness but seriously, it's airborne after sneezing/coughing and no hand washing in the world is going to save you from some idiot hacking on you while you're on the train.
posted by stormpooper at 10:51 AM on November 5, 2009

As some of you figured out, I am in the high risk category - a dad with an infant under 6 months (even under 6 days), so I am just making sure to find out what I need to know. Also a toddler with asthma is in the picture who wouldn't do well with combined the combined effects. I am freakishly freakish about sanitizing our hands. As a family, we have also given up eating out as there is no real way to see how the food is prepped (coughed on, no hand washing, etc...). So thanks for the advice everyone. I know some people feel that this may be nothing to worry about. It may be a passing sickness to most, but I guess where my family is concerned, I feel I should at least try to improve the odds. Thanks again.
posted by boots77 at 11:29 AM on November 5, 2009 [1 favorite]

You're smart to take precautions. Also, it might help to know this -- if anyone in your family does get H1N1, taking Tamiflu within 24-48 hours of onset can seriously improve the course of the illness. It doesn't cure it by any means, but it can cut the duration in half, which is a really good thing. (My daughter was able to start Tamiflu within 24 hours and it's definitely sped up the process for her -- and helped decrease the likelihood of secondary infection, since the super-high, prolonged fever phase was cut short.) The Tamiflu can bring its own issues -- for one thing, the liquid version they give kids is pretty vile-tasting, and for another, it can cause stomach problems -- but having nursed my kids through it one with Tamiflu and one without, I can definitely say that Tamiflu is preferable. I wish we'd been able to have it for my son, but we were out of the 48-hour window by the time we realized what we were dealing with.
posted by mothershock at 1:59 PM on November 5, 2009 [1 favorite]

As some of you figured out, I am in the high risk category - a dad with an infant under 6 months (even under 6 days), so I am just making sure to find out what I need to know.

I sincerely, completely, and publicly apologize for my anger. It was unfounded, and I shouldn't have made assumptions.
posted by Netzapper at 9:44 PM on November 5, 2009

No biggie, Netzapper. It's several months later and no sign of H1N1 in our house (knocking on table). It was such a factory atmosphere that before I knew what questions to ask, I was out the door and in my car. The lit that they gave me wasn't very clarifying. Be safe. And thanks.
posted by boots77 at 5:21 PM on January 10