STUDY OF THE IMMUNOGENICITY OF RECOMBINANT HEPATITIS B VACCINE: COMPARISON OF TWO NATIONAL IMMUNIZATION PROGRAMS IN EGYPT

Abstract

Hepatitis B virus, approximately 2 billion persons, one-third of the world's population, have serologic evidence of past or ongoing infection with the virus. Average 1 million die of hepatitis and its consequences each year. HBV is considered moderately endemic in Egypt with 4% of the population having evidence of chronic HBV infection. Nearly 2 - 3 million Egyptians are chronic carriers of HBV. Vaccination against hepatitis B is the most effective strategy to control HBV infection. Human beings are the sole major reservoir of HBV and hence a complete control strategy by HBV vaccination could lead to virus eradication. HBV vaccine is the first vaccine against a major human cancer. The highest anti-HBs titers are attained 1–3 months following administration of the primary course of hepatitis B vaccine, and are considered a reliable marker of immediate and long-term protection against infection. Anti-HBs response is significantly enhanced after the third injection, with an overall 97–100% anti-HBs ≥10 IU/L. In intermediate and highly endemic countries, universal vaccination without screening of pregnant women is clearly cost-effective. Vertically transmitted HBV infection is becoming an important risk factor for acquisition of HBV among children born after the era of mass vaccination in Egypt. A rate of maternofetal transmission of 51.8% was reported among HBsAg-positive women in Egypt and routine HBV antenatal screening is not practiced. So, stimulated us to perform this work in order to assess the effect of adding the birth dose of HBV vaccine to Egypt’s national immunization program.