Immunogenicity and safety of a virosomal hepatitis A vaccine in HIV-positive patients

Current Take on Systemic Sclerosis Patients' Vaccination Recommendations

Systemic sclerosis (SSc) is a rare autoimmune inflammatory rheumatic disease. The prevalence of SSc ranges from 7 to 700 cases per million worldwide. Due to multiple organ involvement and constant inflammatory state, this group of patients presents an increased risk of infectious diseases. This paper aimed to gather the up-to-date evidence on vaccination strategies for patients with SSc and to be a useful tool for the prevention and management of infectious diseases. The authors conducted a scoping review in which each paragraph presents data on a specific vaccine’s safety, immunogenicity, and efficacy. The work deals with the following topics: SARS-CoV-2, seasonal influenza, S. pneumoniae, HAV, HBV, HZV, N. meningitidis, H. influenzae, HPV, and diphtheria-tetanus-pertussis.

Hepatitis A virus infection and hepatitis A vaccination in human immunodeficiency virus-positive patients: A review

Hepatitis A virus (HAV) is one of the most common infectious etiologies of acute hepatitis worldwide. The virus is known to be transmitted fecal-orally, resulting in symptoms ranging from asymptomatic infection to fulminant hepatitis. HAV can also be transmitted through oral-anal sex. Residents from regions of low endemicity for HAV infection often remain susceptible in their adulthood. Therefore, clustered HAV infections or outbreaks of acute hepatitis A among men who have sex with men and injecting drug users have been reported in countries of low endemicity for HAV infection. The duration of HAV viremia and stool shedding of HAV may be longer in human immunodeficiency virus (HIV)-positive individuals compared to HIV-negative individuals with acute hepatitis A. Current guidelines recommend HAV vaccination for individuals with increased risks of exposure to HAV (such as from injecting drug use, oral-anal sex, travel to or residence in endemic areas, frequent clotting factor or blood transfusions) or with increased risks of fulminant disease (such as those with chronic hepatitis). The seroconversion rates following the recommended standard adult dosing schedule (2 doses of HAVRIX 1440 U or VAQTA 50 U administered 6-12 mo apart) are lower among HIV-positive individuals compared to HIV-negative individuals. While the response rates may be augmented by adding a booster dose at week 4 sandwiched between the first dose and the 6-mo dose, the need of booster vaccination remain less clear among HIV-positive individuals who have lost anti-HAV antibodies.

Epidemiology and prevention of hepatitis A in travelers

BACKGROUND

Hepatitis A is the second most common vaccine-preventable travel-associated infectious disease and hepatitis A virus (HAV) is the most common cause of viral hepatitis. The incidence of infection is closely related to sanitary conditions and the level of economic development.

METHODS

We evaluated HAV incidence, infection-related risk factors, and HAV vaccination rates in international travelers through retrospective analyses using major databases, such as CENTRAL, MEDLINE, EMBASE, and the current literature describing epidemiological data for HAV infection in recent years.

RESULTS AND CONCLUSIONS

We found that the incidence of HAV infection in developed countries is very low. As international travel increases, the incidence of hepatitis A among travelers remains high and likely leads to regional outbreaks. Travelers should visit the Centers for Disease Control and Prevention website or Infectious Disease Prevention Center of their countries to learn about the incidence of infectious diseases associated with their destination before going abroad to determine if they should be vaccinated.

Vaccination against viral hepatitis of HIV-1 infected patients

Reciprocal interactions between HIV and HAV or HBV can increase risk of morbidity and mortality in HIV disease and/or worsened the natural course of the hepatitis viruses. Hepatitis A vaccination is recommended for HIV infected patients at risk for exposure or severe disease: men who have sex with men, injecting drug users, patients with chronic liver disease and patients traveling in high endemic countries. As for healthy adults the scheme of vaccination is two doses 6 or 12 mo apart, nevertheless, seroconversion rates are lower. A third dose could improve the seroconversion rates. Hepatitis B vaccination is recommended for all HIV infected persons lacking prior immunity. As the immune response to hepatitis B vaccines is impaired in HIV-infected adults, four double doses of hepatitis B vaccine could enhance serological response. To assume a higher immune response, vaccines should be administered in HIV-infected patients with undetectable HIV viral load and high CD4 cell count.

Immunogenicity and safety of a pediatric dose virosomal hepatitis A vaccine in Thai HIV-infected children

The immunogenicity and safety of a pediatric dose of a virosomal hepatitis A vaccine (Epaxal®) was evaluated in a group of 45 Thai children with human immunodeficiency virus (HIV) infection, age 2-16 years. Vaccines were administered at 0 and 6 months. Anti-HAV antibody titers were measured at baseline (before injection) 1 and 7 months after primary vaccination. The prevalence of HAV protective antibody in 45 Thai HIV-infected children was 13.6%. The seroprotection rate was 71% at 1 month and 100% at 7 months. The booster dose increased geometric mean concentration (GMC) from 106.5 mIU/ml to 3486.1 mIU/ml. Higher CD4 lymphocyte counts at enrollment was a predictive factor for HAV antibody response. Both doses of Epaxal® were well tolerated. These preliminary data suggest that a pediatric dose of Epaxal® is an effective hepatitis A vaccine for HIV-infected children and should be considered for implementation on a larger scale in the pediatric HIV population.