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(1) Taiwan was the the first in the world to start universal vaccination against hepatitis b virus (HBV), in 1984.
The vaccine then was produced by Merck from human serum. In 1986 California-based Chiron Corporation succeeded in making the first recombinant vaccine, the
hepatitis B vaccine
http://en.wikipedia.org/wiki/Hepatitis_B_vaccine
(section 1 The invention, whose reference 4 is Lawrence M Fisher, Biotechnology Spotlight Now Shines on Chiron. New York Times, Oct 13, 1986.
http://www.nytimes.com/1986/10/13/business/biotechnology-spotlight-now-shines-on-chiron.html
)
, and transferred the technology to Merck, whose product is Recombivax HB (see next).
(2) Recombivax HB. Merck, undated.
http://www.merck.com/product/usa/pi_circulars/r/recombivax_hb/recombivax_pi.pdf
Quote:
"is a non-infectious subunit viral vaccine derived from hepatitis B surface antigen (HBsAg) produced in yeast cells. A portion of the hepatitis B virus gene, coding for HBsAg, is cloned into yeast * * * [after purification] The vaccine contains no detectable yeast DNA but may contain not more than
1% yeast protein.
"RECOMBIVAX HB was shown to be highly immunogenic in clinical studies involving infants * * * Three 5 mcg doses of vaccine induced a protective level of antibody in 100% of 92
infants[10] * * * The protective efficacy of three 5 mcg doses of RECOMBIVAX HB has been demonstrated in neonates born of mothers positive for both HBsAg and HBeAg (a core-associated antigenic complex which correlates with high infectivity). In a clinical study of infants who received one dose of HBIG at birth followed by the recommended three-dose regimen of RECOMBIVAX HB, chronic infection had not occurred in 96% of 130 infants after nine months of follow-up.[16]
Ref 10: Data on file at Merck Research Laboratories.
Ref 16: Stevens, C.E.; Taylor, P.E.; Tong, M.J., et al.: Prevention of Perinatal Hepatitis B Virus Infection with Hepatitis B Immune Globulin and Hepatitis B Vaccine, in Zuckerman, A.J. (ed.), “Viral Hepatitis and Liver Diseases”, Alan R. Liss, 982-983, 1988.
(2) Another recombinant HBV vaccine is
Engerix B. GlaxoSmithKline, undated.
http://www.medicines.org.uk/EMC/medicine/9283/SPC/Engerix+B+20+micrograms+1+ml+Suspension+for+injection%2c+Hepatitis+B+recombinant+vaccine%2c+adsorbed/
Quote:
"In field studies, a protective efficacy between 95% and 100% was demonstrated in neonates, children and adults at risk.
"A 95% protective efficacy was demonstrated in neonates of HBeAg positive mothers, immunised according to the 0, 1, 2 and 12 or 0, 1 and 6 schedules without the concomitant administration of HBIg at birth. However, simultaneous administration of HBIg and vaccine at birth increased the protective efficacy to 98%.
(c) However, US government is not so optimistic, whose conclusion is similar to Taiwan's.
"Clinical trials of the hepatitis B vaccines licensed in the United States have shown that they are 80%-95% effective in preventing HBV infection and clinical hepatitis among susceptible children and adults."
Katz SL et al, Hepatitis B Virus: A Comprehensive Strategy for Eliminating Transmission in the United States Through Universal Childhood Vaccination: Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity and Mortality Weekly Report (MMWR) 40(RR-13); 1-19 (Nov 22, 1991).
http://www.cdc.gov/mmwr/preview/mmwrhtml/00033405.htm
(d) Those who are interested in HBV--particularly its surface antigen (HBs)--may read on.
HBV is made up of a protein coat with double-stranded DNA at the core. The DNA is made up of four genes (S, C, P and X), encoding basically four proteins.
(i) The surface protein (or HBs antigen) has three lengths : L (large, 400 amino acids), M (medium, 281 amino acids), and S (small, 226 amino acids).
(ii) The C gene encodes two proteins: the longer HBc antigen and the shorter HBe antigen.
There are a few graphics in
Henryk Dancygier, Clinical Hepatology; Principle and practice of hepatobiliary Diseases, volume 2. Springer 2010, pages 675-678.
http://books.google.com/books?id=lrPX8C4p90QC&pg=PR6&dq=Henryk+Dancygier,+Clinical+Hepatology;+Principle+and+practice+of+hepatobiliary+Diseases,+volume+2&hl=en&ei=3717TZvrDITmrAHb4rzwBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC0Q6AEwAA#v=onepage&q&f=false
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