Infants being revaccinated against hepatitis B (HepB) could receive just one dose instead of three, under a new recommendation from a Centers for Disease Control and Prevention (CDC) committee.
The CDC’s Advisory Committee on Immunization Practices (ACIP) approved the change Wednesday and also discussed the development of Zika vaccines.
ACIP’s HepB recommendation will be reviewed by the CDC director. If approved, it will be published as an official recommendation in the Morbidity and Mortality Weekly Report. The Academy will review the CDC’s changes and make official policy recommendations of its own.
HepB
The CDC and Academy recommend routine vaccination for all newborns against HepB, a liver infection transmitted through blood or body fluids that can be passed from a mother to her baby.
Infants born to mothers with HepB receive a three-dose HepB vaccine series and hepatitis B immunoglobulin. These infants should be tested after completing the vaccine series. The CDC currently calls for revaccination with a three-dose series for those who aren’t sufficiently protected (those with anti-HBs levels less than 10 milli-international units per milliliter).
ACIP members on Wednesday reviewed data that indicate one revaccination is sufficient for the majority of infants in this situation. Thus, the new recommendation calls for just one revaccination dose followed by serologic testing one to two months later. In addition to being effective for the majority of infants, a single revaccination dose saves both time and money and allows public health cases to be closed more expeditiously.
Infants who still aren’t protected sufficiently following one revaccination should receive two additional doses and be retested, according to the committee. Families would have the option of revaccination with three doses instead of a single dose.
Carrie L. Byington, M.D., FAAP, chair of the AAP Committee on Infectious Diseases, supported the change.
“From the AAP perspective, we would favor the single dose revaccination strategy, as this will be easiest for infants and families,” Dr. Byington said. “Only if infants fail the single revaccination would we recommend completing dose two and three.”
Zika
Vaccine development is underway to protect against Zika virus, which has spread in roughly 50 countries or territories in the Americas in less than two years.
Seven Phase I clinical trials are ongoing with four different vaccine candidates, according to Gerald Kovacs, Ph.D., a consultant for the Biomedical Research and Development Authority. Of those, three are fully U.S.-government supported. Additional vaccines are in research and development and preclinical stages.
Government agencies, in partnership with manufacturers, have been using their knowledge of other flaviviruses and exploring many types of vaccines. They aim to have one vaccine ready to be given to high-risk populations under an emergency use authorization by 2018, with a further goal to begin broad distribution by 2020.
Zika virus, primarily spread by Aedes mosquitoes, is asymptomatic in most people but can cause severe birth defects when passed from a mother to an unborn child. This makes vaccine development even more challenging than for other viruses, Dr. Kovacs said.
“Potentially, we may need to develop a vaccine that is incredibly potent,” he said. “One that not only prevents symptomatic disease in the primary infection but also one that prevents the transmission of the virus from mothers to children.”
In U.S. states and Washington, D.C., 5,041 cases of Zika have been reported, 1,455 in pregnant women. In U.S. territories, there have been 37,447 cases, 3,156 in pregnant women.
