Hepatitis Case Studies

1- Hepatitis is caused by noninfectious agents such as immune, alcoholic and metabolic. Also, it is caused by bacteria, fungi, and viruses. Viral infection such as hepatitis A, B, C, D, & E. All of the hepatitis viruses are RNAs expect hepatitis B. Transmission of Hepatitis B, C, & D is via blood and cause acute and chronic hepatitis. Transmission of Hepatitis A and E is via the fecal-oral route and not cause chronic hepatitis. Chronic hepatitis can progress to fibrosis and hepatocellular carcinoma. Unfortunately, there are no good markers to detect HCC. Only AFP is for detection cancer, and it is a poor marker. However, risk groups are subjected to surveillance every six months by ultrasound, and the cancer diagnosis is by biopsy and imaging.

SEER groups HCC degree by five years survival rate: Localized tumor is 30% five-year survival rate, spread to the lymph nodes is 10% survival rate, spread to other organs is only 3% survival rate.
2- Hepatitis A incubation period is 23 days.

IgM is the first antibody response against hepatitis A and ALT, which is a marker for liver damage raise as well. These two still present around 3-6 months post infection. IgG appears after IgM and persists for years. Hepatitis A vaccine is recommended for risk groups such as healthcare workers, travelers to endemic areas, IV drug users, etc., hepatitis A incidence is higher in undeveloped countries. During HAV vaccine development, HAV and HBV became distinguishable. The short incubation period is hepatitis A, and the long incubation period is hepatitis B. There are many vaccines for hepatitis A. Havrix is the first licensed vaccine. Another hepatitis virus can transmit via fecal-oral is HEV. It is mild and self-limiting. Even it clears without treatment, but immunocompromised patients need treatment. The humoral response is like HAV but milder, IgM, ALT & IgG. There are some vaccine clinical trials phase II

&III.
3- HVB is the major hepatitis virus causes HCC.

There are two stages acute hepatitis B and chronic hepatitis B. The acute phase is with no symptoms and some patients will clear the infection, but some develop to chronic. In fact, infants become chronic carriers by 90% if their mothers have HBV, and who are 1 to 5 years old have a chance to get HBV by 50%. Thus, WHO and CDC recommend vaccine a first dose at 12- 24 hours post birth. HBV vaccine is a recombinant vaccine containing HBsAg giving in three intervals to get a complete production. However, less than 5% of people don't respond to the second dosage, these population may have infected with HBV and should treat with post exposure gamma globulin. Not only mother positive HBV contribute in many cases of chronic infection, but also co-infection with HDV increase fatality by 20%. One of the major agents causes HCC is HCV, which is also acute and chronic infection. ALT rises and associates with symptoms fever, fatigue, and jaundice. There is antibody response post infection, however, antibodies can protect the body. Thus, the CTL-based vaccine is needed. For HCV diagnosis, the serological test uses but after four weeks since abs appear late. RT-PCR use to detect HCV genotypes since there are 6 major genotypes and many subtypes. This is one reason why no HCV vaccine. Many drugs are to treat HCV, but there is a cure for HCV which is called Harvoni and it is effective

98%.

Facts:
1- Harvoni is a cure for HCV. I was surprised when knew. I thought no cure would be for it.
2- No antibodies protect from HVC. Besides genotypes, I was taught that no vaccine is for neither HCV nor HIV because the rate of mutation is high for both.

http://hcvadvocate.org/hepatitis/factsheets_pdf/Similarities_and_Differences_between_HIV_and_HCV.pdf

Question :
HEV is not serious hepatitis infection and cures quickly with no complication. Then why a vaccine is needed? And why does china only have HEV vaccine? How did they develop this vaccine even though there are no good animal models?