Sent to the mailing list on January 25, 2009.

Hey all,

I would like to bring to your attention news reports coming out of Minnesota about a potential outbreak of Haemophilus influenzae type B (Hib). I have info on the vaccine and the disease on www.drjen4kids.com.

The Hib vaccine gives herd immunity, meaning that even if you aren't immunized, there is less Hib up the noses of people near you who have been immunized and that provides protection because there is less Hib to spread. This story out of our neighboring state means that the Hib immunizations rates are low enough to screw up herd immunity. That's just flipping scary. This bacteria is bad. If your child has not been immunized, I would suggest that you think long and hard about reconsidering that decision.

Bottom line. Immunize if you haven't. Please.

Your very concerned Pediatrician,
Dr. Jen

Here are some snippets from the tidal wave of info coming to me..

Background:

Five recent cases of Hib disease in Minnesota suggest potential for an outbreak.

In 2008 Minnesota confirmed five cases of Haemophilus influenzae, type b in children under 3 years of age, one of whom died. Of special concern is that this is the highest number of cases in children under age 5 that Minnesota has seen since 1991.

Three case-patients had received no vaccinations due to parent or guardian deferral or refusal of vaccinations. One child was 5 months old and had therefore received two doses. The other was fully vaccinated for age but, after the Hib infection, was diagnosed with hypogammaglobulinemia (an immune deficiency).

INTERESTINGLY, none of the cases are related each case comes from a different area of the state. This would suggest that herd immunity has also decreased and that there is increasing nasal carrier/colonization. In addition, these young infants were NOT in daycare, suggesting casual or household exposure as the source.

A review of Minnesota vaccination data during this period that found among children aged 7 months, 3-dose primary Hib series coverage was 46.5% AND 18% fewer children had received age-appropriate Hib vaccination compared with pneumococcal conjugate or DTaP vaccination.

As a reminder, Hib vaccine is recommended for all infants and is provided as a two- or three-dose primary series (depending on product), plus a booster shot. Because of a Hib vaccine shortage since November 2007, the only available Hib vaccine product requires that infants receive a primary series of three doses at 2, 4, and 6 months of age. The shortage is expected to last into mid-2009.

During the vaccine shortage, national advisory groups recommended that health care providers defer giving a final booster dose of Hib vaccine to toddlers, age 12-15 months, in the interest of completing the primary series for as many infants as possible.