A prospective, randomized, comparative US trial of a combination hepatitis A and B vaccine (Twinrix®) with corresponding monovalent vaccines (Havrix® and Engerix-B®) in adults

A retrospective pooled analysis assessing the effect of age on the immunogenicity ofHavrix™ in healthy adults

“…These findings are in line with those of a previous study conducted by Joines et al (2001), which presented comparable seroconversion rates between subjects aged 40 years and <40 years, suggesting that both older and younger subjects respond to the inactivated hepatitis A vaccine to the same extent. 43 However, similar to our study, the antibody concentrations in that series were higher in younger adults compared to older adults. 43 The lowest antibody concentration required to confer clinical protection has not been established for hepatitis A.…”

“…43 However, similar to our study, the antibody concentrations in that series were higher in younger adults compared to older adults. 43 The lowest antibody concentration required to confer clinical protection has not been established for hepatitis A. However, studies of passively transferred antibodies have shown that even antibody concentrations just above the detection cut-off are associated with an absence of clinical infection; the detection of circulating antibodies is therefore generally considered as a surrogate marker of clinical protection.…”

Susceptibility to Hepatitis A in Patients With Chronic Liver Disease Due to Hepatitis C Virus Infection: Missed Opportunities for Vaccination *

“…41,42,47 Although some of our patients who received only one dose of the vaccine completed the full course after our study ended, it does raise some concerns that these individuals may not be adequately protected against HAV infection. Additional studies are needed to determine whether an accelerated vaccination schedule 48 or the use of the combination HAV and hepatitis B virus vaccine 49 improves physician and patient compliance with vaccination. In addition to demonstrating that HAV testing and vaccination rates were low in patients with chronic HCV infection, we determined that the incidence rate of acute HAV infection in our subjects was 1.82 per 1,000 personyears.…”

Comparative evaluation of the immunogenicity of combined hepatitis A and B vaccine by a prospective and retrospective trial

“…[7][8][9][10][11] Often combined HAV/HBV vaccines were slightly more effective than their monovalent counterparts. 7,8,10,12 Besides other factors 13 an effect of age on the success of vaccination against hepatitis B has long been suspected, 14,15 whereas the effect of age on HAV seroprotection rates is not well documented.In a previous publication, we reported a failure of combined vaccination against hepatitis A and B in a cohort of more than 100 elderly individuals from a single medical practice that was enrolled in a retrospective survey. After completion of three doses of Twinrix ® under so-called every day conditions the subjects were recalled to give a fresh serum sample 1-36 month (average 16.8) and only 35% of all individuals developed antibodies against both viruses.…”