Vaccine recommendations on the move

Here is startling news: Much of what you know about childhood and adolescent vaccines is passing out of date. New vaccines in development and new mortality data mean that recommendations for vaccination against influenza, hepatitis A, meningococcal disease, varicella, human papillomavirus, and rotavirus are on the move.

"Vaccines are an issue that is changing rapidly," said Penelope Dennehy, MD, director of pediatric infections diseases at Hasbro Children's Hospital and professor of pediatrics at Brown University Medical School, at the AAP 2004 National Conference and Exhibition this week. "Pediatricians need to keep up."

Dr. Dennehy offered her audience a broad look at the exciting landscape of vaccine development in the US:

The crisis shortage of influenza vaccine means that immunization this flu season can be recommended only for children between 6 and 24 months of age, she reminded pediatricians - a significant departure from the established recommendation that was in place earlier this year before the shortage. Immunization this season is also recommended for household contacts and out-of-home caregivers of children younger than 24 months and for children in high-risk groups, including those who have one or more of a number of chronic diseases and conditions.

Mortality data from the Centers for Disease Control indicate, however, that high-risk children are not being vaccinated against influenza. Among infants six months or older who died after contracting influenza in a recent study, 70% had not been vaccinated at all and only 6% had received the recommended two doses.

CDC also found a significant number of fatalities associated with influenza in the very young, not now targeted for vaccination. New vaccination recommendations may be in the works.

A quadrivalent meningococcal conjugate could receive FDA approval for 11- to 55-year-olds as early as this winter. Approval for infants as young as 2 years could follow in two to four years. Look for recommendations in specific high-risk populations, such as residents of college dormitories.

Hepatitis A may be next for new recommendations. Two new vaccines are expected to receive FDA approval in the near future: one for toddlers at 12 months and the other, at 15 months. The new products could convince the CDC to recommend universal vaccination.

Current guidelines call for routine hepatitis A vaccination in states, counties, and communities where the average annual infection rate between 1987 and 1997 was greater than 20 out of every 100,000 persons. Routine vaccination should be "considered" in areas where the average rate of infection was at least 10/100,000 but less than 20/100,000.

Varicella (chickenpox) immunization could change to a two-dose series by 2006. Two manufacturers are developing a measles-mumps-rubella-varicella combination with a two-dose schedule. Two doses increase protection against varicella from 94.4% to 98.3%.

Human papillomavirus is the target of a vaccine program at Merck. The quadrivalent, yeast-derived vaccine is manufactured in Saccharomyces cerevisiae, an organism already used to make vaccines used by millions of children and adults each year. Trials to evaluate efficacy in mid-adult men and women began earlier this year.

Rotavirus is the leading cause of gastroenteritis in the US. One vaccine, RotaShield (Wyeth), was introduced in the US in 1998 and recommended for all infants. The product was withdrawn a year later, however, after a possible link to intussusception, an intestinal obstruction causing prolapse of the intestine into the adjacent distal segment, was found.

Two new vaccines, RotaTec (Merck) and Rotarix (GlaxoSmithKline) are in development. Merck is expected for file efficacy data with the Food and Drug Administration in April 2005; its vaccine could be on the market in 2006. GSK has not announced production or marketing plans for its product.