Abstract Background Although vaccines for hepatitis B virus (HBV) are highly effective. HBV infections in vaccinees occur. Index samples of breakthrough infections are typically anti-HBc negative but HBV DNA positive with protective anti-HBs levels while HBsAg detection may be delayed or absent. HBsAg mutations have been associated with some vaccine breakthrough cases. https://poolsproductscanadas.shop/product-category/jandy-lxi-parts/