Monday, September 14, 2009

ACIP Updates Recommendations for Routine Poliovirus Vaccination

From Medscape Medical News
Laurie Barclay, MD

August 7, 2009 — The Advisory Committee on Immunization Practices (ACIP) has updated its recommendations for routine poliovirus vaccination and published them in the August 7 issue of the Morbidity and Mortality Weekly Report.

The goals of the update are to highlight the importance of the booster dose in children older than 4 years, to extend the minimum interval between dose 3 and dose 4 from 4 weeks to 6 months, to include a new precaution regarding use of minimum intervals in the first 6 months of life, and to recommend schedules for poliovirus vaccination with specific combination vaccines.

"On June 17, 1999, ACIP recommended that all poliovirus vaccine administered in the United States be an inactivated poliovirus vaccine (IPV) beginning January 1, 2000," the report states. "This policy was implemented to eliminate the risk for vaccine-associated paralytic poliomyelitis, a rare condition that has been associated with use of the live oral poliovirus vaccine.... Since 1999, no [oral poliovirus vaccine] has been distributed in the United States."

The 1999 ACIP recommendations specified a routine IPV vaccination schedule of 4 doses given at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years, with 4 weeks being the minimum interval between all IPV doses. In the United States, 3 different combination vaccines containing IPV have been licensed for routine use since the 2000 ACIP recommendation was made in1999.

The updated ACIP guidelines now include the following recommendations to avoid potential confusion related to using different vaccine products for routine and catch-up immunization:

The 4-dose IPV series should still be given at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years.
Regardless of the number of previous doses, the final dose in the IPV series should be given at age older than 4 years.
Between dose 3 and dose 4, the minimum interval is increased from 4 weeks to 6 months.
Between dose 1 and dose 2, and between dose 2 and dose 3, the minimum interval is still 4 weeks.
For dose 1, the minimum age is still 6 weeks.

Another new ACIP recommendation is that use of the minimum age and minimum intervals for vaccination in the first 6 months of life are recommended only if the vaccine recipient is at risk for imminent exposure to circulating poliovirus; for example, during an outbreak or for travel to a polio-endemic region. The rationale for this new precaution is that shorter intervals and earlier start dates result in lower seroconversion rates.

ACIP is also recommending a poliovirus vaccination schedule with specific combination vaccines, as follows:

When DTaP-IPV/Hib (Pentacel, Sanofi Pasteur) is given at ages 2, 4, 6, and 15 to 18 months (4 doses total), children should receive an additional booster dose of age-appropriate IPV-containing vaccine (IPV [Ipol, Sanofi Pasteur] or DTaP-IPV [Kinrix, GlaxoSmithKline]) at age 4 to 6 years, resulting in a 5-dose IPV vaccine series.

The booster dose at age 4 to 6 years should not be DTaP-IPV/Hib.

For optimal booster response, the minimum interval between dose 4 and dose 5 should be at least 6 months.
As per current recommendations, a booster dose should be given as soon as feasible to a child missing an IPV dose at age 4 to 6 years.

Morb Mortal Wkly Rep. 2009;58:829–830.

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