FAQ about Hepatitis B Vaccination
Hepatitis B vaccination is incorporated into the National Immunization Programmer from 2002 in china. However, many people still have no idea about the method and its precautions; so it is necessary to make a brief introduction.
Why get Hepatitis B vaccination?
China belongs to high and middle level hepatitis B virus (HBV) prevalence area. The transmission routes are by blood contact, mother-to-child transmission, broken skin and mucous membrane, and sexual contact. Perinatal transmission is the main type of mother-to-child transmission, which occurs when exposed to blood or body fluids of HBV-positive mother during her childbirth. Hepatitis B Vaccination is the mainstay of preventing HBV infection. Neonatal immunization against hepatitis B will confer newborns with the protection against hepatitis B disease, therefore to avoid the serious consequences of HBV infection during childhood, including liver cancer and cirrhosis. So it is beneficial to prevent cirrhosis and liver cancer while doing hepatitis B vaccination.
What are the categories and mechanism for Hepatitis B vaccine?
The blood sources vaccine used in 1970-1980s had been eliminated because of high risk and high cost of plasma, while the genetic engineering Hepatitis B vaccine are available world-wide nowadays. The genetic engineering technology is used to recombinant HBsAg gene segments to elicit protective immune response through specific protective antibodies. These vaccines could be used in prophylactic of all known subtypes of HBV.
Hepatitis B vaccine's proper use and indication.
(1)Newborn of healthy parents should vaccinate against Hepatitis B by intramuscular injection within 24 hours after birth for its first dose, and then a second dose and a third dose one month and six months later respectively. This is calls 0-1-6 Schedule, and it will help the newborns to confer higher antibody titers at its seventh month. Adults should do serological test before vaccination. If the hepatitis B surface antigen negative and the transaminase is normal, the 0-1-6 schedule will be followed. The HBsAg antibody positive indicates a successful immunization and the serological convert ratio will be above 85% by 0-1-6 schedule; as long as HBsAg antibodies keep, the immune protection will remain.
(2)Infants born to HBV-infected mothers should receive Hepatitis B vaccine and Hepatitis B immune globulin within 12 hours of birth. It has been reported that the better protection will be achieved if vaccinates a 10µg/0.5ml dosage.
(3)Newborn born to HBsAg and e-antigen double positive mother should be administrated the combination of Hepatitis B vaccine and high titer hepatitis B immunoglobulin (dose ≥100 IU) A.S.A.P., one dose (≥100 IU) hepatitis B immunoglobulin after birth and one dose (≥100 IU) a month later, and Hepatitis B vaccine (10µg) at Month 2, 3 and 5 respectively. Or alternatively, administering one dose of hepatitis B immunoglobulin after birth, and Hepatitis B vaccine (10 or 20 µg) at month 0, 1 and 6 respectively. Both schedules will confer a protection rate above 90%.
How to do if Hepatitis B vaccination fails to generate adequate protective antibodies?
(1) In case of retardation of immunological respond, which means vaccinated cohort takes longer time for immune reaction, a booster of 1~2 doses or the revaccination with appropriate dosage may be recommended.
(2) The four doses immunization schedule (Month 0, 1, 2 and 12 respectively) can be followed.
(3) Small dosage of IL-2 can be administrated along with Hepatitis B vaccine.
(4) The BCG or smallpox vaccine could be vaccinated to increase their immune response.
How long does protection from Hepatitis B vaccination?
The antibodies elicited by Hepatitis B vaccination will decrease with the time go by. After three doses of entire procedure, usually, 97% of subjects can be assayed the surface antibody one month later and will remain two years at the titer level; in the third year, the titer descend to 74%. Whether or not to boost subject to Hepatitis B surface antibody level. If the titer is less than or equal to 10 IU/ml, should be revaccinated in six months; Most Chinese scholars recommend that it is better to receive a booster dose within 5 years post the primary series to get a long term protection from HBV infection.
Studies also indicate that immunologic memory remains intact for at least 20 years among healthy vaccinated individuals who initiated Hepatitis B vaccination >6 months of age. The vaccine confers long-term protection against clinical illness and chronic Hepatitis B virus infection. Cellular immunity appears to persist even though antibody levels might become low or decline below detectable levels.
Can Hepatitis B vaccine be administered concurrently with other vaccines?
Yes. When Hepatitis B vaccine has been administered at the same time as other vaccines, no interference with the antibody response of the other vaccines has been demonstrated. Separate body sites and syringes should be used for simultaneous administration of injectable vaccines.
The mainstay measure for postexposure prophylaxis (PEP) is by Hepatitis B vaccine
(1) Who naïve to the Hepatitis B vaccination should be administered hepatitis B immunoglobulin within 24 hours, and Hepatitis B vaccine one week later.
(2) Who haven't gone through full 0-1-6 primary schedule should finish its schedule after hepatitis B immunoglobulin.
(3) who has vaccination history and hepatitis B surface antibodies remained positive will not take measures; otherwise, a booster shot of Hepatitis B vaccine should be done. Who have no immune response to Hepatitis B vaccine should be injected one dose of hepatitis B immunoglobulin and Hepatitis B vaccine as early as possible.
Hepatitis B vaccination risk factors evaluation
Hepatitis B vaccine is made from a part of the hepatitis B virus. It cannot cause HBV infection or other infectious diseases. The vaccine is manufactured under strict GMP condition and no ingredient in culture media are of animal origin. The Hepatitis B vaccine (Hansenula) proved to be safe and effective after clinical observations, has been one of the safest vaccine technologies so far. However, it is worth mention that there are prone to be endangered due to the unqualified vaccination procedure, in the event that administrated with unqualified vaccine or damaged and deteriorate vaccine, the negligence of the aseptic injection operations, or sharing syringe or needle. Some people are carrier of dormant infection, the virus in very low level and the serological test do not sensitive and can be detectable only by RNA PCR method; under this scenery, the Hepatitis B vaccination may not stimulate the protective antibodies.
What should people do in remote areas since the universal immunization is hard to achieve?
Under the circumstances, at least the following risk population groups for HBV infection should be vaccinated: all newborns and children in kindergartens, personnel in dangerous occupations (such as infectious disease hospital, department of stomatology, hemodialysis, blood station, or nurses, etc.), users of blood products, fresh military serviceman, patients before organ transplantation, persons with chronic immunosuppressant, household contact with HBV carriers, dangerous sexual activities.
Is the Hepatitis B vaccine necessary for a hepatitis B virus carrier?
Hepatitis B Vaccine (Hansenula) is for prophylaxis and will not protect hepatitis B patients or HBV carriers. They shall follow the prescription of doctors for such a treatment. For persons who were infected therefore obtaining protective antibodies (which demonstrated by serological markers test), it is not necessary to vaccinate; However the hepatitis B vaccination do not pose adverse reactions towards this cohort, and its surface antibodies level may possibly increase after the vaccination. For people with acute hepatitis B, if they recovered after active treatment (which means the surface antigens negative and the core antibodies are still positive), but the protective antibodies cannot elicit themselves, in this case, these people may receive the hepatitis B vaccine to generate the protective surface antibodies, and they will get the protection for HBV.