FDA, CDC Play Complementary Roles in Vaccine Policy-Making

By Will Boggs MD

NEW YORK (Reuters Health) - The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) play complementary roles in establishing vaccine policy, and their differing roles can be a source of confusion for healthcare professionals, according to a new report.

"The most important point is to clarify the effort that is invested by so many people at FDA and CDC in determining safety (and) timing in terms of which vaccines are added to the schedule," said Dr. H. Cody Meissner from Tufts Medical Center in Boston.

"The vaccine schedule is an exhaustively considered document and many factors go into deciding when a vaccine is added and the timing of the vaccine administration," he told Reuters Health by email.

Dr. Meissner and colleagues explain the reasons for apparent differences between FDA-approved prescribing information and CDC recommendations for vaccine use in a paper online August 23 in Pediatrics.

The FDA's Center for Biologics Evaluations and Research (CBER) is charged with regulating vaccines and ensuring the safety and effectiveness of vaccines that are available to the public.

After considering manufacturing data and results from animal studies and human clinical trials, CBER determines whether a vaccine is safe and effective for its intended use and, if so, ultimately approves prescribing information that includes indications and usage, dosage and administration, contraindications, and so on. This prescribing information is updated as needed.

Once a vaccine is approved by the FDA, the CDC's Advisory Committee on Immunization Practices (ACIP) considers not only FDA-approved labeling, but also disease epidemiology, burden of disease, economic analyses and implementation issues in establishing how the vaccine should be used in the civilian population.

Only occasionally do these different roles lead to CDC recommendations that do not align perfectly with FDA-approved prescribing information. The authors cite two examples.

First, current Tdap vaccines (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis, adsorbed) are not approved by the FDA for use in pregnant women to prevent pertussis in young infants. The CDC, however, recommends Tdap administration to pregnant women during every pregnancy in an effort to optimize the prevention of pertussis in infants who are too young to have completed the primary vaccine series but who experience the highest morbidity and mortality from pertussis.

The authors note that the absence of an FDA-approved indication in the prescribing information for a vaccine may simply represent a lack of sufficient data submitted to the FDA for review, rather than the presence of data revealing that its use in a particular setting is ineffective or unsafe.

Second, the FDA licensed the intranasal live attenuated influenza vaccine FluMist Quadrivalent, but the CDC recommended against its use for the 2016-2017 and 2017-2018 influenza seasons based on observational studies that revealed limited vaccine effectiveness from 2013 to 2016.

This example shows that the CDC may recommend one vaccine over another to provide the greatest public health impact from vaccination when multiple vaccines have the same indication.

Dr. Meissner said that it's "very seldom that a difference arises between FDA and CDC recommendation."

"There is only one vaccine schedule," he said. "If parents or pediatricians elect to use a different schedule from what is recommended, the extraordinary benefit that vaccines provide may not be derived by the child."

SOURCE: https://bit.ly/2NakKm0

Pediatrics 2018.

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