Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang®vaccine in adolescents from low income families in Central Brazil

Abstract

In order to evaluate the seroepidemiology and response to Butang® vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. Further, three 20 µg Butang® vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182)Hepatitis B virus (HBV) has been considered a global health problem. This has been cause of acute and chronic hepatitis, cirrhosis, and cancer of the liver (Mast et al. 2005). It is estimated 2 billion people have been infected and that more than 350 million of individuals are chronic carriers of HBV worldwide (Hou et al. 2005). Also, this infection has been answerable for 520,000 deaths each year (EASL 2003).In high endemic regions, hepatitis B is transmitted mainly by vertical or horizontal mode. In contrast, in low and intermediate endemic regions, it is disseminated generally by sexual and parenteral via (Hou et al. 2005, Mast et al. 2005 whereas an increase of HBV positivity throughout the adolescence and early adulthood was showed (Dominguez et al. 2000, Cisneros-Castolo et al. 2001, Gaze et al. 2002. During this period of life individuals are more susceptible to risk behaviors such as illicit drug use, alcohol abuse, multiple partners, and sexually transmitted diseases (Lawrence & Goldstein 1995, Miranda et al. 2005). Also, a higher risk of hepatitis B has been observed in economically disadvantaged adolescents (Porto et al. 1994, Silveira et al. 1999, Clemens et al. 2000, Gandolfo et al. 2003. Hepatitis B vaccination is the most effective strategy for HBV prevention. In Brazil, it has been available in private clinics since the beginning of 1990s, but due the elevated cost of doses only individuals with better socioeconomic conditions could be vaccinated. In 1999, in compliance with WHO recommendations (WHO 2003) the Brazilian Public Health Authorities implemented the universal hepatitis B vaccination for newborns and infants, and more recently it was extended for adolescents.Actually several countries manufacture the hepatitis B vaccines. This should play a role in the cost of doses and to improve the worldwide hepatitis B vaccine coverage, mainly in developing regions (Vryheid et al. 2000). Butang® is a Brazilian hepatitis B recombinant vaccine (Ioshimoto et al. 1999). It has been provided free of charge by health public services since 2001. However, there is still few informations about the immunogenicity of this vaccine in different groups (Baldy et al. 2004, Martins et al. 2004.In order to assist decisions on strategies for hepatitis B vaccination in a target group of the Brazilian immunization program, an investigation was carried out to evaluate the prevalence and risk factors for HBV infection, the adherence to and the...

Hepatitis B marker seroprevalence and vaccination coverage in adolescents in the City of Itajaí, State of Santa Catarina, Southern Brazil, in 2008

“…In contrast, this prevalence is lower than that of Greece (2.5%) 24 and of developing regions, where HBV vaccination programs are only partially implemented or not implemented at all, such as Mexico (5%) 25 , Bolivia (6.9%) 26 and central Brazil (5.9%) 27 .…”

Brazilian hepatitis B vaccine: a six-year follow-up in adolescents

“…Previous work demonstrated a significant association between protective anti-HBs titres (following primary vaccination) and the magnitude of the anamnestic response (Chaves et al 2010) that gradually declines over time (Chaves et al 2012), suggesting that elevations in the anti-HBs titres following the primary vaccination would be protective despite a case report describing a previously vaccinated male who was chronically infected with HBV (O'Halloran et al 2011). The administration of three doses of 20 µg of the Brazilian HBV vaccine successfully elicited the production of protective antibodies in high-risk adolescents in GO (Oliveira et al 2006) and the present study further supports these observations regarding the effectiveness of this vaccine in the medium term.…”

“…A total of 170 susceptible adolescents were vaccinated with the Brazilian recombinant hepatitis B vaccine (20 µg) at zero, one and six months as recommended in the state of Goiás (GO) (Central Brazil) at the time. All participants developed protective anti-HBs following the administration of a complete vaccine regimen, resulting in a geometric mean titre (GMT) of 4.344 mIU/mL (Oliveira et al 2006). This scenario represented a unique opportunity to investigate the effectiveness of the Brazilian HBV vaccine six years after the primary vaccination in a target group.…”

Presence of maternal anti-HBs antibodies does not influence hepatitis B vaccine response in Brazilian neonates

“…The advantage of this yeast expression system when compared to other expression systems (such as Saccharomyces cerevisiae) is that its expression is 4-10 times higher, reducing the production costs (Hieu et al 2002). This vaccine was introduced in the National Immunization Program in 2001 (MS 2003) and it is highly immunogenic in individuals less than 30 years of age (Baldy et al 2004, Martins et al 2004, Oliveira et al 2006.…”

“…This vaccine has proven to be highly immunogenic and safe (Baldy et Martins et al 2004, Isolani et al 2006, Oliveira et al 2006). The first dose was administered at the maternity hospital within 12 h of birth.…”