Carriers who have seroconverted to HBeAg negative status, in particular those who acquired the infection as adults, have very little viral multiplication and hence may be at little risk of long-term complications or of transmitting infection to others. However, it is possible for individuals to enter an "immune escape" with HBeAg-negative hepatitis. PCR tests have been developed to detect and measure the amount of HBV DNA, called the viral load, in clinical specimens. These tests are used to assess a persons infection status and to monitor treatment. Individuals with high viral loads, characteristically have ground glass hepatocytes on biopsy. Prevention
Vaccine
Vaccines for the prevention of hepatitis B have been routinely recommended for babies since 1991 in the United States. The first dose is generally recommended within a day of birth. The hepatitis B vaccine was the first vaccine capable of preventing cancer, specifically liver cancer.Most vaccines are given in three doses over a course of days. A protective response to the vaccine is defined as an anti-HBs antibody concentration of at least 10 mIU/ml in the recipients serum. The vaccine is more effective in children and 95 percent of those vaccinated have protective levels of antibody. This drops to around 90% at 40 years of age and to around 75 percent in those over 60 years. The protection afforded by vaccination is long lasting even after antibody levels fall below 10 mIU/ml.
It is mostly (96.6%) circulating in its original form; only a small proportion is metabolized by the liver enzymes UGT1A1 and UGT1A3, resulting in a glucuronide.The drug is mainly excreted via the faeces (93.3%). Less than 2% is found in the urine. Chemistry
Letermovir is used as the free acid. It is a white to off-white, amorphous powder that is slightly hygroscopic, very slightly soluble in water, and very soluble in acetonitrile, acetone, dimethylacetamide, ethanol, and 2-propanol.The molecule has one asymmetric carbon atom, which is in S configuration. References
External links
"Letermovir". Drug Information Portal. U.S. National Library of Medicine. "Letermovir Injection". MedlinePlus.