Effect Measure

CDC is again warning parents not to send your children to a swine flu party. The idea is to provide them with immunity, like used to be done with chickenpox parties. It’s pretty hard to believe this is a live issue and CDC admits it doesn’t have evidence that any have actually occurred. When it came up in the spring, during the first wave of H1N1, we and all other flu experts said it was a very bad idea, but at least one could understand the reasoning then. Since there was no vaccine and the worry was that swine flu might come back in the fall in altered and worse form during flu season, it was understandable that some people might have the idea it was better to get it then, when it was being described as “mild illness” than take their chances in a full blown pandemic in the fall when the virus might have increased virulence. It was still a lousy idea, because even then it was clear that the virus was a malignant lottery ticket that usually didn’t pay off with a severe or fatal illness, but like any lottery ticket it could. That was then. But now? You would have to be seriously stupid or certifiably crazy to even consider it now. It’s probably urban legend. But just to be on the safe side, let’s go over how incredibly dumb it would be.

First of all, it’s already flu season, so any reasons someone might have had in the spring are moot. The virus is back, it isn’t more virulent than the spring but it’s bad enough. It can kill young healthy adults and children or put them on machines that breathe for them. If the idea is to “self-vaccinate” because the vaccine is delayed and you don’t want to wait, that is so dumb it is hardly even worth pointing out why, but I’ll do it anyway because someone that dumb has to have it spelled out for them. The reason to get vaccinated is to lessen the chances of your child getting the flu if exposed. So deliberately exposing unvaccinated children to the flu would be exactly the outcome a parent should be most concerned about. If the idea is that naturally acquired immunity is better than immunity acquired “artificially” from a vaccine, that’s probably true. But the risk of side effects from naturally acquired flu are thousands of times higher and more serious than the side effects from the conventional vaccines used for swine flu, so the trade-off isn’t even close. And what appears to be a mild respiratory disease in one child can kill another child. Virulence is a combined effect of the virus, the host and the environment. Some kids draw the short straw and we don’t know why. CDC points out that exposing your child to another child with a febrile respiratory disease doesn’t mean you are exposing them to swine flu, since there are a lot of viruses out there.

CDC says it not only gets calls about swine flu parties but sees them mentioned in social media networks. Pretty hard to believe, although there are some seriously demented people out there running on about swine flu conspiracies. In comparison swine flu parties seem comparatively sane. But it’s like the old Henny Youngman joke (which I keep using because it works for so many things): “Hey, Henny, how’s your wife?” Henny: “Compared to what?”

Comments

#1 Al Delaney
October 26, 2009

“If the idea is that naturally acquired immunity is better than immunity acquired “artificially” from a vaccine, that’s probably true.”

What’s the science behind this statement for the current vaccine. I could agree with this if it were about some of the old vaccines where a related virus was used, like cowpox, but not for the swine flu I don’t believe the above statement holds up.
#2 Greg Laden
October 26, 2009

I doubt anyone is that dumb …

Seriously?
#3 Ian Tester
October 26, 2009

So, let me get this straight. People are sending their kids to “parties” with sick people so that they get the flu too. They do this in order to avoid possibly getting it later. Wait, what?

Option A: Go to flu party.
Outcome: Very likely to get the flu.

Option B: Go about life normally.
Outcome: Much less likely to get the flu.

Is this the kind of stupidity that results from all the fear in the media about the flu vaccine and vaccines in general?
#4 revere
October 26, 2009

Al Delaney: Studies have shown that whole virus inactivated vaccines offer somewhat better protection than split virus vaccines but have more adverse reactions. The current vaccines have only a small portion of potential viral antigens in them (we hope the most important epitopes), but the immune response is fairly complicated and not well understood (see a post here we did on this subject).
#5 phytosleuth
October 26, 2009

Attending school during a local epidemic of swine flu is different than a swine flu party?
#6 linzel
October 26, 2009

I just switched schools. My first day in the new town, I have 8 absent of 22. Other class 5 of 24. All sick. I’m wondering what their symptoms are.
#7 Mike
October 26, 2009

Sorry for being somewhat off-topic, but any chance of a comment on this:
http://www.theatlantic.com/doc/200911/brownlee-h1n1/

The author seems to have an agenda (I judge this based on the book she has written), but still. Anything here?
#8 Peter Ellis
October 26, 2009

Actually, there is one remaining (and very cynical) reason why someone might choose to go to a swine flu party.

It is quite possible that when the pandemic wave peaks, the country will run out of critical care beds. Since that is the case, then it makes sense to get your own case of ‘flu in early, before the critical beds run out, just in case you’re one of the unlucky folk who needs one. In simplest terms: if you catch flu today and end up in intensive care, you’re still very likely to live. If you catch an equivalently severe case and there are no intensive care beds available, you will almost certainly die.

It’s not clear that it’s mathematically the wrong thing to do.
#9 revere
October 26, 2009

Peter: You mean you think it’s rational to hope you will wind up on a ventilator before they are all gone as the best outcome?
#10 Curious
October 26, 2009

“That is so dumb it is hardly even worth pointing out why, but I’ll do it anyway because someone that dumb has to have it spelled out for them.” That may be my favorite thing you’ve ever written.

Here’s what I’m hearing right now among parents: “I wish they’d just get it and get it over with so I can quit worrying.” Which is nonsensical, of course, but a logical wish. We are all hoping our kids are going to be okay, and the wait is hard.

I wonder if some parents are caving to that anxiety, that “let’s just get it over with” mentality. Maybe the fear is just unbearable and that’s why swine flu parties pop up.

But I agree, dumb.

Then again, anyone who goes to school right now seems to be attending a swine flu party. On Friday, there were 10 absent out of my daughters’ small school — normal for this time of year (200 students, K-8). Today, 30 percent were absent, and the school closed for the week.

Here’s a question for those of us who want to protect our kids. I’ve got one kid just on the other side of H1N1, but my 4-year-old is symptom free. If (by some miracle) I can get her the vaccine this week, but then she catches the flu from her sister, is her risk of severe infection higher because of the double dose to her immune system? I want to keep her safe, but I also don’t want to make things worse.
#11 Jon Pear (a.k.a. NeuroAster)
October 26, 2009

That is just sickening (no pun intended)
#12 SocaticGadfly
October 26, 2009

Why does anybody have problems believing this? Parents in California already have measles parties and such.
#13 BostonERDoc
October 26, 2009

I have sent 3 individuals with h1n1 positive PCR testing to the unit for respiratory failure as a consequence of H1N1 2009 influenza in the past 4 days. My ED also had a 4 yo who we transferred to a pediatric facility for severe respiratory distress as a consequence of H1N1 flu this week. A Flu party could be the last you or your family member attends so I am with Revere: attendance to one will get you nomindated for the Darwin award.
#14 Marilyn Mann
October 26, 2009

With regard to natural immunity probably being better than immunity acquired from a vaccine, there are also people saying that the swine flu vaccine, if it works, will possibly cause a future pandemic to kill more people than it otherwise would. The concept is that if there is a future pandemic with a related but more lethal strain, people who get the swine flu this time will be better off than if they had been vaccinated because they will be less likely to become seriously ill or die. This seems highly speculative to me.
#15 Lauren
October 26, 2009

Sounds like that good old logic of kill my kid now to prevent him from dieing later.
http://www.newsy.com/videos/h1n1_emergency_or_inconvenience
#16 Peter Ellis
October 26, 2009

Revere: Technically, it could indeed be rational.

It’s not that you’re hoping to wind up on a ventilator. It’s that you know you’re likely to get flu anyway, so it’s better to get it when there’s a safety net (i.e. now) than when there isn’t (i.e. at the peak of the pandemic). Let’s build an extremely simple model to show how the numbers could work out.

Let’s model the pandemic as 5 phases. Basing this on the UK population of ~60 million:

1) Early stages (10 weeks)
Infection rate: 0.2% of the population as new cases per week
0.1% of cases require intensive care
0.01% of cases are fatal (since there are enough intensive care beds to go round)

2) Rising phase (4 weeks)
Infection rate: 1% of the population as new cases per week
0.1% of cases require intensive care
0.02% of cases are fatal (since there are not quite enough intensive care beds to go round)

3) Pandemic peak (4 weeks)
Infection rate: 5% of the population as new cases per week
0.1% of cases require intensive care
0.09% of cases are fatal (since intensive care beds are completely swamped).

4) Declining phase (4 weeks)
Infection rate: 1% of the population as new cases per week
0.1% of cases require intensive care
0.02% of cases are fatal (since there are not quite enough intensive care beds to go round)

5) Getting back to normal (10 weeks)
Infection rate: 0.2% of the population as new cases per week
0.1% of cases require intensive care
0.01% of cases are fatal (since there are enough intensive care beds to go round)

I know it’s a simplistic model, but it’s not outrageous. We have 32% of the population getting infected, the majority of them during a 4 week peak. That’s consistent with previous pandemics and with the predictions for this one. Flu virulence remains constant throughout. Critical care rates and death rates aren’t out of line with the cases / predictions to date. All that changes is whether the system is able to cope with the load of critical patients.

The key point comes in when you look at the probability of dying. If you take no action one way or the other, your probability of death is (4/32 * 0.1%) + (8/32 * 0.2%) + (20/32 * 0.9%) = 0.625%, whereas if you go to a party and catch it in the first few weeks, you have only a 0.1% chance of dying.

Of course, it’s a tragedy of the commons situation – if everyone decided to deliberately catch it, you’d overwhelm the system right from the start, and then everyone ends up with the worst case figure: a 0.9% chance of death. Much worse than if you’d just let the pandemic play out unchanged. Therefore it’s obviously something that should be strongly discouraged!

Moreover, it ignores the vaccine, which is [i]the[/i] most important consideration, bar none. Vaccination beats treatment any day. If a high pandemic wave hits any given country before the vaccine is rolled out to the full population (and has had time to take effect), then the fatality rates are going to go way up.

The simple fact is that no country has enough intensive care beds to cope with all the severe cases, when you have ~30% of the population falling sick, and that’s what’s likely to happen in a pandemic sitution. The “epidemic” threshold for the UK is 200 consultations per 100,000 population per week. Critical care beds can cope with that. The can probably cope with several times that. But in a pandemic situation you’re looking at a peak rate of several percent of the population per week – something like 25 times the normal “epidemic” rates. That means shortages, and deaths that wouldn’t happen if the treatment were available.
#17 Paula
October 26, 2009

I have to agree with Peter Ellis on this, even though I cannot quite make even myself just go to a crowded event and “get it over with.” Where I work and live, there are two community hospitals within a 65-mile radius, a population of 80,000 or more persons, at most 6 ICUs, most nurses’ training extremely variable, the state did not trouble to get in adequate antivirals, roads often snow-covered in winter. Persons over 65 here are de facto prohibited from getting vaccine despite higher chances of complications should they get it, and even though, of persons who have died of laboratory-confirmed 2009H1N1 in the US so far, 7 percent (approx 70), have been over-65s, a proportion not so dissimilar to that (9.6 percent) among children. Does it not make sense for persons, especially old persons, who have almost no chance of obtaining vaccine before spring, in this region to expose themselves before the pandemic peaks and/or the roads are impassible?
#18 Chris
October 26, 2009

Mike, revere has commented on the Atlantic story. Go look on the left side under “Recent Posts” for Journalists sink in The Atlantic article on vaccines.

I saw on Tara Smith’s blog, Aetiology, that some parents were considering another dumb plan: having a chicken pox party in the play area of a McDonald’s restaurant.
#19 M. Randolph Kruger
October 26, 2009

FOR THE RECORD….

IF YOU ARE DUMB ENOUGH TO SEND OR TAKE YOUR KID(S) TO A SWINE FLU PARTY AND ONE BECOMES SICK, THE CHILD CAN AND WILL BE REMOVED FROM YOUR HOME FOR RECKLESS ENDANGERMENT……

IF THE CHILD BECOMES SICK AND DIES, YOU CAN BE HELD IN I THINK I WAS TOLD IN THE LAST BRIEFING ALL BUT 5 STATES AND CHARGED WITH MANSLAUGHTER …

Herein defined….

Involuntary manslaughter is the unlawful killing of a human being without malice aforethought. It is distinguished from voluntary manslaughter by the absence of intention. It is normally divided into two categories; constructive manslaughter and criminally negligent manslaughter.

Want to take your chances with your local DA then by all means do so. If you are having these parties and someone dies you are an accessory to the crime. If you do it, knowing having testified on the stand that you knew people died or were dying of flu, then they can in most of the southern states up it to Manslaughter II.

But only a retard would even be thinking about doing something like this. The prosecutors would be more than happy to send you to jail for either II or III any day of the week.

Good post Revere.
#20 Karen
October 26, 2009

Well, I found out that some of my friends would consider this before using the vaccination. I was speaking to them of my amazement that people would do this. I should know better. My kids and I then had a nice discussion on risks, benefits, probabilities and unwillingness to think critically. Also included – it’s good to know where people stand and how to make your own decisions.
#21 caia
October 26, 2009

“Two things are infinite: the universe and human stupidity; and I’m not sure about the universe.” — Albert Einstein

I suppose you meant anyone here, but even that represents an audacious leap of faith.
#22 Paula
October 26, 2009

M.R. Kruger, I seriously doubt that any parent desperately worried for her/his child is going to worry about anything as minor as a manslaughter change, if s/he thinks a “swine flu party” is the safest option for the children.
#23 IanW
October 27, 2009

We already have flu parties. They’re called schools, workplaces, malls, etc., etc.
#24 Weirded-out
October 27, 2009

I’ve never heard of such ‘parties,’ this is a first, I think I’m beginning to understand the logistics behind them. Any parent that wishes to play with fire will, however, get burnt. But again, before the vaccine had been manufactured this would have been a very reasonable way of reasoning – something I’d never have considered, clever (however weird this may sound, it is) all the same.

If one decides not to get the H1NI vaccine when it is offered and prefers to actually catch the virus, acquiring natural immunity later on, isn’t she/he exactly like the parents of such party attendants? No?

Remember: there are also risks concerning the administration of the vaccine.
#25 phytosleuth
October 28, 2009

We open schools in August knowing full well that the vaccine isn’t going to make it until mid-Nov or December and we call THAT responsible public health? Sorry. Not buying it.
#26 Michael
October 28, 2009

It would be interesting, and perhaps helpful from a public health standpoint, to develop a wild estimation of one’s chances of catching the flu at the height of the flu season if you head out to spend the night at a bar.

And in a related question: if you DID go out for such an evening, and were absolutely scrupulously careful about not touching your nose, eyes etc, how much would your chances be reduced? What percentage of the “flu-catching” probability in such a situation comes purely from airborne transmissions? And could those transmissions be reduced if better ventilation were required in bars and such places during flu season?

Anyone want to try some estimations? Obviously there’d be a wide margin of error, but it should be possible to come up with something…
#27 Paula
October 29, 2009

Phytosleuth, re no. 25, I’ve tried to follow that one, too. I think it is an issue of “the economics” [i.e., keeping the children locked in so the parents can labor] trumping public health, respect for life, or anything like. But sticking kids into ventilation-free, mind-quelching, obedience-training schools does that already, doesn’t it? The virus highlights the threat rather more, though.
#28 Michael
October 31, 2009

No one has any estimates/ideas of how dangerous (in terms of likelihood of catching the flu if you’re not immunized) it would be to go out and hang in a crowded bar for a full evening at the height of flu season (actually, if google’s graphs are to be believed we are NOW at the high point of flu season’s high points of the last five years… so how about how dangerous it is NOW?)

Or any input on what effect doubling or tripling a bar’s ventilation might have on one’s chances?