October 24, 2003

VUMC helps influence policy change for infant flu shot

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Robin Matulich, LPN, gives Cade MacMillan, 22 months, a flu vaccine in Dr. Rachel Mace's clinic. Dana Johnson

VUMC helps influence policy change for infant flu shot

Flu prevention initiatives got a shot in the arm last week when the Centers for Disease Control and Prevention voted to recommend that all children 6- to 23-months old receive the influenza vaccine, starting with the 2004 flu season. The decision strengthens the CDC’s previous position, which only “encouraged” vaccines for healthy infants in that age range.

The Advisory Committee on Immunization Practices based its vote partially on data provided at the Oct. 14 meeting from the New Vaccine Surveillance Network, a CDC-sponsored study led by Vanderbilt researchers Drs. Marie Griffin, professor of Preventive Medicine and Medicine, and Kathryn Edwards, professor of Pediatrics and vice-chair of Pediatric Research. Results from their ongoing study, now entering its fourth year, show flu among young children is a bigger problem than previously thought.

“Flu is not just another cold. It’s worth preventing, and it’s also worth not transmitting it to other people,” Griffin said after returning from the CDC. “Anybody in the medical community should know to recommend to patients that they be immunized. We need to educate our community about influenza and about how it can harm certain vulnerable groups, and that we have a pretty good way to prevent it with the vaccine.”

In the study, 30 percent of all influenza-related hospitalizations in children younger than 5 were in children in the now-targeted age group of 6 to 23 months. Previously, the CDC recommended that only “high risk” children in that bracket, those with chronic diseases such as asthma, diabetes or chronic heart, lung or kidney disease, receive the vaccine. But in the Surveillance Network study, 74 percent of the children hospitalized were not “high risk,” according to Griffin and Edwards’ data.

Less than one-third of children at high risk for getting flu were vaccinated. “Expanding the influenza recommendations to healthy children aged 6 to 23 months will likely result in more high-risk children receiving vaccine as well,” Griffin said.

At Vanderbilt, 9 percent of the patients with respiratory infections admitted to Children’s Hospital and 9 percent of children seen in the Pediatric Emergency Department during the relatively mild 2002 flu season had the flu bug; less than 10 percent of the 505 children screened had received flu shots.

Dr. William Schaffner, professor and chair of Preventive Medicine, is a member of the CDC committee and was present at the presentation. The data Griffin and Edwards delivered “provided scientific rational for considering influenza vaccines in this age group.”

Until now, Griffin said, the vaccine message was muddled — children 6 to 23 months were “encouraged” to get the shots, but it was “recommended” for their high-risk cohorts. The fragments confused practitioners and children slipped through the cracks.

Although the change in verbiage might seem like an exercise in semantics, Griffin said similar previous changes have reaped rewards: When the minimum age for adults to get the flu shot was changed several years ago to 50 instead of age 65, the system cast a wider net and caught many high-risk people between those ages who were not getting the vaccine.

Griffin now hopes that with a simplified message more practitioners will recommend flu shots.

Another CDC concern, Schaffner said, was the feasibility of physicians giving the vaccines.

“Across the United States, 6 million children will have to go to their doctor’s offices in a few months’ time to get the vaccine. The committee was given evidence that it could be done. Now physicians can work out the nitty gritty on how to do this for next season,” he said.

For the past two seasons, Vanderbilt’s Pediatric Acute Care Clinic has provided the flu vaccine to anyone, according to Dr. Greg Plemmons, assistant professor of Pediatrics and medical director of Vanderbilt Children’s Hospital Outpatient Clinics.

Children younger than 6 months are still not advised to get the vaccine, although they made up more than half of all hospitalizations due to flu in children 5 years and younger. Studies show that it’s more difficult to stimulate an immune response in these youngsters. That makes it even more important for parents and siblings to be vaccinated in order to protect the youngest among us, Griffin says.

The study combined three years’ worth of surveillance at Vanderbilt Children’s Hospital, Summit and Metro General Hospital, and from collaborative partners at the University of Rochester in New York. Last year, the study included outpatient data from Vanderbilt’s Pediatric Emergency Department and the Pediatric Acute Care Clinic, Green Hills Pediatrics and Centennial Pediatrics.

Other Vanderbilt collaborators were Dr. Katherine Poehling, assistant professor of Pediatrics; Yuwei Zhu, a bio-statistician in Pediatrics; Yi-Wei Tang, associate professor of Medicine and Pathology; and Jennifer Doersam, research assistant in Pediatric Infectious Diseases.