Related Experiment Videos
Exposure of Indian children to hepatitis A virus & vaccination age
M S Chadha1, S D Chitambar, N J Shaikh
1National Institute of Virology (ICMR), Pune.
Insights
In India, most children contract Hepatitis A virus (HAV) early. Vaccination against HAV is recommended by 9-10 months, after maternal antibodies wane, to protect young children.
Area of Science:
- Pediatrics
- Virology
- Immunology
Background:
- Hepatitis A virus (HAV) infection is highly prevalent in India, with 90% of children exposed by age six.
- Understanding the timing of early childhood HAV infections is crucial for effective prevention strategies.
Purpose of the Study:
- To determine the peak age of Hepatitis A virus (HAV) infection in early childhood.
- To identify the optimal age for Hepatitis A vaccination in the Indian pediatric population.
Main Methods:
- Blood samples were collected from 499 Indian children aged three days to six years.
- Antibodies against Hepatitis A (anti-HAV) were tested to assess infection exposure and maternal antibody levels.
- Statistical analysis was used to correlate age with IgG anti-HAV antibody levels and infection rates.
Main Results:
- A significant negative correlation between IgG anti-HAV and age was observed up to 11.67 months, with minimum positivity (9.25%).
- HAV exposure increased significantly after maternal antibodies waned, rising from 28.9% at 13-15 months to 52.5% by two years and 90.9% by six years.
- HAV infection rates show a marked increase in children over one year of age.
Conclusions:
- Hepatitis A vaccination in India should be administered by 9-10 months of age.
- Immunization at this age coincides with the disappearance of maternal antibodies, offering protection before significant exposure occurs.
- Vaccination by 9-10 months is a key preventive measure against widespread HAV infection in Indian children.
Abstract:
It is known that 90 per cent of children in India are exposed to hepatitis A virus (HAV) by the age of six years. The aim of the study was to determine when in early childhood maximum HAV infections take place and to deduce an appropriate age for vaccination against HAV. Blood samples of 499 children between the ages of three days and six years were collected and tested for the presence of antibodies against hepatitis A. A statistically significant negative correlation between IgG anti-HAV and age was observed (P < 0.01) up to 11.67 months when IgG anti-HAV positivity was found to be minimum (9.25%). Subsequently a significant positive correlation was noted (P < 0.01). Exposure to HAV was 28.9 per cent soon after the waning of maternal antibodies in the 13-15 month age group which increased to 52.5 per cent by two years of age and 90.9 per cent by 6 yr. It is concluded that in addition to other preventive measures, if children in India are to be vaccinated against hepatitis A they should be immunised against HAV by 9-10 months of age when the maternal antibodies disappear.