Universal Single-Dose Vaccination against Hepatitis A in Children in a Region of High Endemicity

Abstract

Since August 2012, universal single-dose vaccination in children aged at least three years has been implemented in the Republic of Tuva, which was previously the region most affected by hepatitis A in Russia. The objective of this cross-sectional study was the assessment of the immunological and epidemiological effectiveness of vaccination program five years following its implementation. In the pre-vaccination period, anti-HAV antibody detection rates in Tuva was 66.0% [95% CI: 56.3–74.6%] in children aged 10–14 years and reached a plateau (>95%) by age 20–29 years. Annual incidence rates in children under 18 years of age peaked at 450–860 per 100,000 in pre-vaccination years but dropped to 7.5 per 100,000 in this age group and to 3.2 per 100,000 in the total population one year after the start of vaccination. Since 2016, no cases of hepatitis A has been reported in Tuva. Serum anti-HAV antibodies were quantified in samples from healthy children following single-dose vaccination. Protective anti-HAV antibody concentrations (≥10 mIU/mL) were detected in 98.0% (95% CI: 96.2–99.0% (442/451)) of children tested one month after single-dose immunization, in 93.5% (95% CI: 91.0–95.4% (477/510)) and in 91.1% (95% CI: 88.2–93.4% (422/463)) of children one year and five years after single-dose immunization, respectively. Anti-HAV antibody geometric mean concentrations were similar in sera collected one month, one year, and five years following single-dose vaccination: 40.24 mIU/mL, 44.96 mIU/mL, and 57.73 mIU/mL, respectively (p > 0.05). These data confirm that single-dose vaccination is an effective method of bringing hepatitis A under control in a short period of time in a highly endemic region.

The Impact of an Inactivated Hepatitis A Vaccine with One Dose in Brazil: A Retrospective Time-Series

“…This recommendation was followed by other low and middle income countries of Latin America as Brazil, Chile and Colombia introduced hepatitis A vaccination in their childhood immunization schedules [31]. Other countries outside Latin America have shown similar positive effects after the use of a single-dose hepatitis A vaccine, such as Russia [32]. Our study results mirror high immunogenicity acquired after the first dose of hepatitis A vaccine.…”

Perspective Technologies of Vaccination: Do We Still Need Old Vaccines?

“…The vaccine program reduced the incidence of infection in children from 450-860 per 100,000 to 7.5 per 100,000 in children below 18 years old, and to 3.2 per 100,000 in the total population one year after introduction. The data vividly proves that a single-dose vaccination program is effective in the control of hepatitis A, even in the high-endemicity regions [28].…”

“…The next step is to monitor the vaccine efficacy in the clinical application, constituting an important part of vaccination programs. Mikhailov et al presented an article entitled "Universal single-dose vaccination against hepatitis A in children in a region of high endemicity" [28]. The authors performed a cross-sectional study to assess the immunological and epidemiological effectiveness of hepatitis A vaccination programs over a five-year period after the commencement of the program.…”

Recent Advances in Protective Vaccines against Hepatitis Viruses: A Narrative Review

“…The positive impact of single-dose HA inactivated vaccine programs on FHF and liver transplantation in children has been increasingly demonstrated in Argentina, Brazil, and Russia [ 178 , 179 , 180 ]. In fact, the reported incidence of HAV decreased by 80–99% in all age groups.…”