Vaccine's Protection Against Hepatitis B: 20 Years and Up

VAIL, COLO. — Immunization at birth against hepatitis B protects against symptomatic disease for at least 20 years, despite frequent exposures, according to several recent studies.

Whether newborn immunization provides protection for life without the need for booster doses is still an open question.

Experts continue to monitor the hepatitis B vaccine's long-term effectiveness, and recommendations for booster doses will be issued, should evidence show they are necessary.

But the recent reports suggesting that the duration of protection is 2 decades and counting are quite encouraging, Dr. Myron J. Levin said at the conference, which was sponsored by the Children's Hospital, Denver.

He cited a meta-analysis by investigators at Tehran (Iran) University of Medical Sciences, who included 34 studies with more than 9,300 subjects.

The researchers determined that the rate of breakthrough infection was extremely low: 0% in the first 5 years post vaccination, 0.06% during years 6–10, 0.2% in years 11–15, and 0% in years 16–20 (Vaccine 2010;28:623–31).

Even more encouraging was a study of 204 Thai children who were immunized at birth and born to chronically infected hepatitis B surface antigen–positive mothers.

These children, living in a highly endemic area for hepatitis B, have been followed for 17 years with annual clinic visits and serologic studies.

The frequent transient presence of hepatitis B surface antigen and/or hepatitis B core antibody indicated that these subjects were indeed heavily exposed to hepatitis B virus throughout their childhood and adolescence.

Yet no one with transient hepatitis B surface antigen developed any clinical symptoms of liver disease.

And no cases of chronic hepatitis B occurred in the study population (J. Infect. Dis. 2009;200:33–8). In other words, the vaccine did exactly what it's supposed to do: It prevented clinical disease, observed Dr. Levin, professor of pediatrics and medicine at the University of Colorado, Denver.

A key element in the persistence of protection against clinical hepatitis B in patients who were immunized as children is immune memory.

This was underscored in a study of 493 Alaskan children who had been immunized 22 years earlier, although not at birth. At follow-up, 60% of subjects still had protective levels of vaccine-induced antibody (defined as 10 mIU/mL).

Of the remaining 193 subjects, 160 (83%) demonstrated a rapid rise in antibody level in response to a booster. This early spike in antibody is evidence of immune memory, whereby the immune system is able to kick in and provide the needed protection upon exposure to hepatitis B, even though the level of protective antibody in a vaccinated person declines with time.

If it is assumed that immune memory indicates protection, 93% of subjects in this study were still protected against hepatitis B at 22 years after vaccination. The investigators concluded that booster doses aren't needed (J. Infect. Dis. 2009;200: 1390–6).

Dr. Levin said that regardless of how long it ultimately turns out that protection against hepatitis B persists after childhood vaccination, it's absolutely necessary that physicians do a better job of making sure neonates get a birth dose of vaccine while they're still in the hospital. At present, this occurs in only about one-half of neonates born in the United States. As a result, roughly 8,000 infants per year are chronically infected with hepatitis B.

Dr. Levin disclosed that he has served as a consultant to Merck & Co. and GlaxoSmithKline. Both companies make hepatitis A and B vaccines.

A key element in the persistence of protection in patients immunized as children is immune memory.

Source DR. LEVIN

VAIL, COLO. — Immunization at birth against hepatitis B protects against symptomatic disease for at least 20 years, despite frequent exposures, according to several recent studies.

Whether newborn immunization provides protection for life without the need for booster doses is still an open question.

Experts continue to monitor the hepatitis B vaccine's long-term effectiveness, and recommendations for booster doses will be issued, should evidence show they are necessary.

But the recent reports suggesting that the duration of protection is 2 decades and counting are quite encouraging, Dr. Myron J. Levin said at the conference, which was sponsored by the Children's Hospital, Denver.

He cited a meta-analysis by investigators at Tehran (Iran) University of Medical Sciences, who included 34 studies with more than 9,300 subjects.

The researchers determined that the rate of breakthrough infection was extremely low: 0% in the first 5 years post vaccination, 0.06% during years 6–10, 0.2% in years 11–15, and 0% in years 16–20 (Vaccine 2010;28:623–31).

Even more encouraging was a study of 204 Thai children who were immunized at birth and born to chronically infected hepatitis B surface antigen–positive mothers.

These children, living in a highly endemic area for hepatitis B, have been followed for 17 years with annual clinic visits and serologic studies.

The frequent transient presence of hepatitis B surface antigen and/or hepatitis B core antibody indicated that these subjects were indeed heavily exposed to hepatitis B virus throughout their childhood and adolescence.

Yet no one with transient hepatitis B surface antigen developed any clinical symptoms of liver disease.

And no cases of chronic hepatitis B occurred in the study population (J. Infect. Dis. 2009;200:33–8). In other words, the vaccine did exactly what it's supposed to do: It prevented clinical disease, observed Dr. Levin, professor of pediatrics and medicine at the University of Colorado, Denver.

A key element in the persistence of protection against clinical hepatitis B in patients who were immunized as children is immune memory.

This was underscored in a study of 493 Alaskan children who had been immunized 22 years earlier, although not at birth. At follow-up, 60% of subjects still had protective levels of vaccine-induced antibody (defined as 10 mIU/mL).

Of the remaining 193 subjects, 160 (83%) demonstrated a rapid rise in antibody level in response to a booster. This early spike in antibody is evidence of immune memory, whereby the immune system is able to kick in and provide the needed protection upon exposure to hepatitis B, even though the level of protective antibody in a vaccinated person declines with time.

If it is assumed that immune memory indicates protection, 93% of subjects in this study were still protected against hepatitis B at 22 years after vaccination. The investigators concluded that booster doses aren't needed (J. Infect. Dis. 2009;200: 1390–6).

Dr. Levin said that regardless of how long it ultimately turns out that protection against hepatitis B persists after childhood vaccination, it's absolutely necessary that physicians do a better job of making sure neonates get a birth dose of vaccine while they're still in the hospital. At present, this occurs in only about one-half of neonates born in the United States. As a result, roughly 8,000 infants per year are chronically infected with hepatitis B.

Dr. Levin disclosed that he has served as a consultant to Merck & Co. and GlaxoSmithKline. Both companies make hepatitis A and B vaccines.

A key element in the persistence of protection in patients immunized as children is immune memory.

Source DR. LEVIN

VAIL, COLO. — Immunization at birth against hepatitis B protects against symptomatic disease for at least 20 years, despite frequent exposures, according to several recent studies.

Whether newborn immunization provides protection for life without the need for booster doses is still an open question.

Experts continue to monitor the hepatitis B vaccine's long-term effectiveness, and recommendations for booster doses will be issued, should evidence show they are necessary.

But the recent reports suggesting that the duration of protection is 2 decades and counting are quite encouraging, Dr. Myron J. Levin said at the conference, which was sponsored by the Children's Hospital, Denver.

He cited a meta-analysis by investigators at Tehran (Iran) University of Medical Sciences, who included 34 studies with more than 9,300 subjects.

The researchers determined that the rate of breakthrough infection was extremely low: 0% in the first 5 years post vaccination, 0.06% during years 6–10, 0.2% in years 11–15, and 0% in years 16–20 (Vaccine 2010;28:623–31).

Even more encouraging was a study of 204 Thai children who were immunized at birth and born to chronically infected hepatitis B surface antigen–positive mothers.

These children, living in a highly endemic area for hepatitis B, have been followed for 17 years with annual clinic visits and serologic studies.

The frequent transient presence of hepatitis B surface antigen and/or hepatitis B core antibody indicated that these subjects were indeed heavily exposed to hepatitis B virus throughout their childhood and adolescence.

Yet no one with transient hepatitis B surface antigen developed any clinical symptoms of liver disease.

And no cases of chronic hepatitis B occurred in the study population (J. Infect. Dis. 2009;200:33–8). In other words, the vaccine did exactly what it's supposed to do: It prevented clinical disease, observed Dr. Levin, professor of pediatrics and medicine at the University of Colorado, Denver.

A key element in the persistence of protection against clinical hepatitis B in patients who were immunized as children is immune memory.

This was underscored in a study of 493 Alaskan children who had been immunized 22 years earlier, although not at birth. At follow-up, 60% of subjects still had protective levels of vaccine-induced antibody (defined as 10 mIU/mL).

Of the remaining 193 subjects, 160 (83%) demonstrated a rapid rise in antibody level in response to a booster. This early spike in antibody is evidence of immune memory, whereby the immune system is able to kick in and provide the needed protection upon exposure to hepatitis B, even though the level of protective antibody in a vaccinated person declines with time.

If it is assumed that immune memory indicates protection, 93% of subjects in this study were still protected against hepatitis B at 22 years after vaccination. The investigators concluded that booster doses aren't needed (J. Infect. Dis. 2009;200: 1390–6).

Dr. Levin said that regardless of how long it ultimately turns out that protection against hepatitis B persists after childhood vaccination, it's absolutely necessary that physicians do a better job of making sure neonates get a birth dose of vaccine while they're still in the hospital. At present, this occurs in only about one-half of neonates born in the United States. As a result, roughly 8,000 infants per year are chronically infected with hepatitis B.

Dr. Levin disclosed that he has served as a consultant to Merck & Co. and GlaxoSmithKline. Both companies make hepatitis A and B vaccines.

A key element in the persistence of protection in patients immunized as children is immune memory.

Source DR. LEVIN