A recent survey on the incidence of Hepatitis B among teenagers has revealed that childhood vaccine effect fades towards adolescence.
The results of this survey have been published in the latest issue of the journal Hepatology.
Hepatitis B: Statististics and Characteristics
HBV or the Hepatitis B Virus is the causative agent of hepatitis- inflammation of liver. More than 2 billion people around the world suffer from this infectious disease. CDC has put the mark at 1.4 million as the number of Americans who are chronic carriers of this virus.
It is said that infection of the infants from the mothers is the main cause of chronic carriers. The main symptoms of hepatitis are cirrhosis, liver failure and liver cancer. In this scenario, HBV vaccination during infancy has been recommended by public health offices worldwide and even made mandatory in most developed countries.
Study on School Children
The research conducted by investigators at Mackay Medical College, Taiwan says that though HBV vaccinations are effective the protection is not 100%. According to them, long-term success of the current vaccines is debatable.
To prove the point researchers conducted a survey on 8733 high school teens born between 1987 and 1991, within a mean age group of 16 years. Of them 53% were male. The vaccination records of these students were examined for HBsAg and their antibodies.
It was found that the 2% of the sample population tested positive for the presence of the antigen and 48% for antibodies. Among those who received vaccination as infants, 15% tested positive for the antigen; whereas among those who were not vaccinated the percentage was significantly low.
Recommendations of the Author
The study came to the conclusion that HBV vaccination was effective in protecting children from life threatening diseases such as cancer and hepatitis, but failed to provide extended protection beyond teenage.
Hence the lead author of the study, Dr. Wang suggests that a booster dose of HBV at the age of 15 should be made mandatory especially for those adolescents who were born to HBV antigen positive mothers and other high-risk teenagers.