OU researcher finds protection extends well into teen years
Vaccines given in infancy to guard against hepatitis B continue to provide protection in adolescence, according to a study by a researcher at the University of Oklahoma Health Sciences Center and colleagues in Texas.
The study looked at children who received the recommended three doses of the hepatitis B vaccine during infancy.
It has been known for some time that children and adolescents who received the hepatitis B vaccination series had long-lasting protection against the disease. However, researchers said less is known about how long protection lasts when the vaccination series is administered in infancy.
“There was some concern that giving the dose in these little infants might change the duration of protection, necessitating a booster dose later in life,” said Amy B. Middleman, M.D., M.S.Ed., M.P.H., principal investigator and chief of adolescent medicine at the OU College of Medicine.
So researchers looked at teenagers, 16 to 19 years of age, who had been vaccinated against hepatitis B as infants.
The study involved 420 teenagers who had received all three doses of the hepatitis B vaccine before the age of one. Researchers focused on immune response to a dose of vaccine given to the participants to mimic exposure to the disease, referred to as a challenge dose. They measured antibody levels in the teens before and after exposure to the challenge dose of vaccine.
“Pediatricians were voicing concern because they would run blood tests to determine the degree of protection for their patients and they would find that their patients’ hepatitis B antibody levels were zero,” Middleman said. “So the providers felt they needed to give the patients a booster dose of vaccine for protection.”
Prior to the challenge dose, most of the teens in the study (76 percent) showed antibody levels lower than what is thought necessary to protect against infection. However, the study found that 92 percent were, in fact, protected. Following the challenge dose, their antibody levels exceeded that needed for protection against hepatitis B infection.
“Even among the adolescents who had zero or low levels of hepatitis B antibodies, the study showed these adolescents were still capable of mounting an immune response,” Middleman said.
The study separated the teens into two groups: those who received the first dose of hepatitis B vaccine within seven days of birth and those who received it at or after four weeks of age.
Although the study found those immunized a little later in infancy mounted a more vigorous immune response, the same proportion of adolescents in each group achieved a response that indicates protection from the disease.
“Based on these data, it does not appear a booster dose of the hepatitis B vaccine is needed for adolescents who received all three doses of the vaccine as an infant; if a patient has been fully vaccinated, they are likely fully protected,” Middleman said.
In 1991, the Centers for Disease Control and Prevention initiated a comprehensive program for the elimination of hepatitis B in the United States. A large part of that strategy included the recommendation for universal immunization with recombinant hepatitis B vaccine in newborns.
Researchers pointed out that it will be important to follow up with a similar population 20 to 25 years after infant vaccination to see if protection against hepatitis B extends into the third decade of life.
The study was funded by the Centers for Disease Control and Prevention project 00HCVJHB-2009-67553
It is published online in Pediatrics, the official journal of the American Academy of Pediatrics.
The Surgery Was Among the First Ever to be Performed in the State on a Pediatric Patient
Oklahoma City- They ranged from small, nearly unnoticeable twitches to terrifying and life-threatening grand mal seizures, and for nearly her entire life, seizures have been a near-daily event for 11-year-old Hermoinee Lorett.
But following one of the first pediatric surgeries ever performed in Oklahoma attaching electrodes directly to the brain’s surface, Hermoinee had a successful epilepsy brain surgery at The Children’s Hospital at OU Medical Center. She’s been seizure free since May.
Hermoinee’s mother, Deena Lorett, said her little girl is improving in leaps and bounds. She’s laughing more, her personality is blooming. Hermoinee is learning, developing and growing cognitively as an 11 year old should.