Here's where it comes from.

It's 1985, and the CDC is gearing up to introduce the old, crappy hib polysaccaride vax.

http://www.cdc.gov/mmwr/preview/mmwrhtml/00022818.htm

So they're saying one in 1,000 kids under age 5 developed invasive Hib. Ok.

But then they multiply that by 5 to make it one in 200 kids by age 5.

Anybody see the problem there?

ETA:

You often hear "20,000 cases of Hib disease a year prevaccine!"

One in 1,000 in babies 0-12 months is 4,000 cases...times the first 5 years of life (coz that's how they get the "one in 200 by age 5" figure) is 20,000 cases a year.

That has to be where the "20,000 cases of hib disease a year prevaccine!" comes from.

It's 1985, and the CDC is gearing up to introduce the old, crappy hib polysaccaride vax.

http://www.cdc.gov/mmwr/preview/mmwrhtml/00022818.htm

Quote:

April 19, 1985 Several population-based studies of invasive Hib disease conducted within the last 10 years have provided estimates of the incidence of disease among children under 5 years of age, the major age group at risk. These studies have demonstrated attack rates of meningitis ranging from 51 cases per 100,000 children to 77/100,000 per year and attack rates of other invasive Hib disease varying from 24/100,000 to 75/100,000 per year (1). Thus, in the United States, approximately one of every 1,000 children under 5 years of age develops systemic Hib disease each year, and a child's cumulative risk of developing systemic Hib disease at some time during the first 5 years of life is about one in 200. Attack rates peak between 6 months and 1 year of age and decline thereafter. Approximately 35%-40% of Hib disease occurs among children 18 months of age or older, and 25% occurs above 24 months of age |

But then they multiply that by 5 to make it one in 200 kids by age 5.

Anybody see the problem there?

ETA:

You often hear "20,000 cases of Hib disease a year prevaccine!"

One in 1,000 in babies 0-12 months is 4,000 cases...times the first 5 years of life (coz that's how they get the "one in 200 by age 5" figure) is 20,000 cases a year.

That has to be where the "20,000 cases of hib disease a year prevaccine!" comes from.

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