![]() Therefore, through measuring the immune response to a booster dose of vaccine in definite post‐primary vaccination periods, we can assess the presence of anamnestic immune response, and potentially assess the long‐term immunity induced by hepatitis B vaccine against HBV infection.Īs unnecessary hepatitis B revaccination is wasteful, none of the international guidelines recommend booster doses to be applied universally ( WHO 2003 John 2005 Puro 2005 Mast 2006). Accordingly, the serologic response to a booster dose may be considered as a surrogate marker for assessing the presence of protection against the wild virus. Clinical infection can be measured by detecting clinical symptoms and verifying the diagnosis of acute hepatitis B infection using hepatitis B serology.Ī practical approach in determining the duration of protection provided by hepatitis B vaccine could be if we assume that the response to a booster dose of hepatitis B vaccine mimics the response to hepatitis B wild virus infection. Subclinical infection can be detected by measuring the occurrence of anti‐HBc. When anti‐HBs levels fall to low or undetectable levels, a HBV vaccine booster dose may raise antibody levels, leading to increased protection against subclinical and clinical HBV infection. ![]() Indeed, it is not clear whether a decline in serum anti‐HBs level implies the need for a booster dose of the vaccine or not. In the context of these relatively limited results, the duration of immunity provided by a complete course of primary vaccine is unknown because vaccine protection may not be parallel to the anti‐HBs titre. Moreover, adults are less likely than infants to demonstrate an anamnestic response of their immune reaction to the HBV or hepatitis B vaccine as they grow older ( Samandari 2007), and the risk of HBV infection increases by sexual and occupational exposures during adulthood ( Whittle 2002). Nonetheless, a HBV breakthrough infection, detected by the presence of the hepatitis B core antibody (anti‐HBc) in the blood, and chronic HBV carriage, detected by the presence of HBsAg in the blood, are reported in some vaccinees, especially in endemic regions ( Hadler 1986 Liao 1999 McMahon 2005). Hence, disappearance of the antibody may not necessarily imply loss of protection against hepatitis B infection. In addition, immunologic studies have revealed that hepatitis B vaccine induces immunologic memory, so that memory B cells can proliferate, differentiate, and retain the capacity to generate a rapid and vigorous anamnestic immune response upon re‐exposure to hepatitis B surface antigen (HBsAg), even if the anti‐HBs titre falls below 10 mIU/mL ( Watson 2001 van der Sande 2007). The evidence based on several long‐term follow‐up studies has indicated that the protection provided by three or four doses of monovalent hepatitis B vaccine during the primary vaccination persists for at least two decades ( Poorolajal 2009b Poorolajal 2010a). We need evidence, based on randomised clinical trials, to formulate future booster vaccination policies. There is no scientific evidence, based on randomised clinical trials, to support or reject the need for booster doses of hepatitis B vaccine in healthy individuals with normal immune status. We were unable to find any eligible randomised clinical trials to include in this review. Randomised clinical trials addressing immune response (i.e., the way your body recognises and defends itself against bacteria, viruses, and substances that appear foreign and harmful to the body) to a booster dose of hepatitis B vaccine, more than five years after the primary vaccination in apparently healthy participants, vaccinated in a three‐dose or four‐dose schedule of hepatitis B vaccine during their primary vaccination, without receiving an additional dose of the hepatitis B vaccine or immunoglobulin. The authors selected to assess the benefits and harms of a booster dose of hepatitis B vaccine, more than five years after the primary vaccination.Įlectronic searches were performed up until January 2016. This question may potentially be answered indirectly by measuring the anamnestic immune response to a booster dose of vaccine given to people previously immunised with the hepatitis B vaccine. Booster dose for preventing hepatitis B infectionĪntibodies against hepatitis B surface antigen (HBsAg) wane over time following hepatitis B immunisation hence, it is unclear whether people vaccinated in 3‐dose or 4‐dose schedules of the hepatitis B vaccine during their primary vaccination are still immune when the hepatitis B surface antibody (anti‐HBs) level in their body is undetectable, or lower than the level usually considered protective.
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