Archief Roodbont

In 2000, the inactivated poliovirus vaccine (IPV) replaced the oral poliovirus vaccine (OPV) for routine immunization in the United States to prevent vaccine-associated paralytic polio, as reported by the American Academy of Pediatrics (AAP) in the December 1999 issue of Pediatrics. In the January 24, 1997, issue of MMWR. Recommendations and Reports, the US Centers for Disease Control and Prevention found that approximately 8 cases of OPV-associated paralytic polio occurred per year. Three combination vaccines that include IPV are licensed for use in the United States, according to the Centers for Disease Control and Prevention in the August 7, 2009, issue of MMWR. Morbidity and Mortality Weekly Report.

This policy statement from the AAP addresses the recommendations for poliovirus vaccination.

Study Synopsis and Perspective

The AAP has updated its recommendation for the administration of poliovirus vaccines, clarifying the standard schedule for immunization, as well as the minimal ages and minimal intervals between doses, according to a policy statement published online September 26 in Pediatrics.

Although the use of the OPV beginning in the early 1960s led to the elimination of polio in the United States, with the last reported outbreak seen in 1979, wild polioviruses still occur naturally in 4 countries: Afghanistan, India, Nigeria, and Pakistan. The fact that these 4 countries exported the virus to other countries that reported polio cases in 2009 points to the potential for the virus to be brought into the United States, the AAP policy statement says.

Twenty countries reported 1349 cases of polio in 2010, and 14 countries have reported 333 polio cases through August 23 of this year.

The IPV replaced the OPV as the vaccine of choice in the United States in 2000 in an effort to prevent rare but serious vaccine-associated paralytic polio. The current vaccination schedule, designed to produce immunity early in life, calls for 3 doses of IPV at 2, 4, and 6 through 18 months of age, and a fourth dose at 4 through 6 years of age. The AAP recommends that if risk for exposure is imminent, such as when a person travels to 1 of the 4 countries with wild polioviruses, then the doses should be administered at the minimum ages and intervals.

Within the United States, pockets of underimmunized children could lead to an outbreak if the wild viruses migrate to where those children are living, the AAP says.

The AAP statement says that after an individual receives the IPV series of doses, immunity is "long-term, possibly lifelong." However, another recommendation in its statement is that even adults who completed immunization with OPV or IPV early in life get a single dose of IPV if they are at increased risk for exposure to wild poliovirus in 1 of the countries.

Three combination vaccines and 1 stand-alone vaccine are licensed in the United States. Diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B (DTaP-HepB-IPV; Pediarix, GlaxoSmithKline), is licensed for the first 3 doses and through 6 years of age. DTaP, IPV, and Haemophilus influenza type b (DTaP-IPV/Hib; Pentacel, Sanofi Pasteur) is licensed for all 4 doses through 4 years of age. DTaP-IPV (Kinrix, GlaxoSmithKline) is licensed for the last dose at ages 4 through 6. IPV (Poliovax, Sanofi Pasteur), the stand-alone vaccine, is licensed for all doses in infants, children, and adults.

The World Health Assembly set a goal in 1988 of eradicating polio worldwide. At that time, an estimated 350,000 cases of polio existed in 125 countries. That number decreased to 1604 cases in 2009.

Pediatrics. Published online September 26, 2011. Full text

Related Link
The Centers for Disease Control and Prevention provides extensive information on Polio Vaccination for healthcare professionals and patients, including downloadable patient teaching tools available in English and Spanish.

Study Highlights

• The last reported poliovirus outbreak in the United States occurred in 1979.
• Worldwide, poliovirus cases decreased from 1604 cases in 2009 to 1349 cases in 2010.
• The US population is at risk for poliovirus because of imported cases and because of underimmunized children.
• The estimated cost of medical care is $520,000 per case of poliovirus.
• The seroconversion rate is more than 95% after administration of the 3-dose primary vaccine series.
• Seroconversion rates and geometric mean titers are affected by maternal antibody, the age of the child, and the interval between doses.
• Seroconversion rates for serotypes 1, 2, and 3 are higher when the vaccine is given at ages 2, 4, and 6 months vs ages 6, 10, and 14 weeks.
• Seroconversion rates and geometric mean titers are lower in children with higher maternal antibody levels; the number of maternal antibodies usually decreases as the children get older.
• Antibody levels are lower in children who received the vaccine in 1-month vs 2-month intervals.
• The duration of immunity after the IPV series might be life-long.
• Countries that provide an IPV booster dose at age 4 years or older show sustained elimination of polio.
• 4 IPV preparations are available in the United States:
  • IPV for ages 2, 4, 6 to 18 months, and 4 to 6 years
  • DTaP-HepB-IPV for ages 2, 4, and 6 months
  • DTaP-IPV-Hib for ages 2, 4, 6, and 15 to 18 months
  • DTaP-IPV for ages 4 to 6 years
• The standard immunization schedule is IPV doses at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years.
• For those at risk for imminent exposure to poliovirus from travel or outbreak, the following minimal ages and intervals for IPV doses should be used:
  • The minimal age for dose 1 is 6 weeks.
  • The minimal interval is 4 weeks between doses 1 and 2 and between doses 2 and 3.
  • The minimal interval is 6 months between doses 3 and 4.
• The final IPV dose should be given at ages 4 to 6 years and at least 6 months after the previous dose, regardless of the number of previous doses.
• Immunocompromised and immunodeficient children should follow the same IPV schedule as children with normal immune systems, although the vaccine might not be as effective.
• Adults at increased risk for exposure to polio can receive a single IPV dose, even if the primary IPV or OPV immunization series was completed.

Clinical Implications

• The standard schedule for IPV in children is a total of 4 doses at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years, with at least a 4-week interval between doses 1 and 2 and doses 2 and 3, and at least a 6-month interval between doses 3 and 4. The final dose should be given at ages 4 to 6 years regardless of the number of prior doses.
• For children at risk for imminent exposure to polio, the recommended inactivated poliovirus vaccine schedule can begin at the minimal age of 6 weeks. Adults can receive a single IPV dose even if primary immunization with OPV or IPV is complete.