The impact of one dose Hepatitis A vaccine in Latin America Dr. Pablo Elmassian

Hepatitis A: Burden of disease HAV cases: 1,5 millions annually worldwide Fulminant hepatic failure (FHF): 0,4% (Mortality rate 60%) Case fatality ratio: 0,1% < 15 years of age to 2,1% > 40 years HAV does not cause chronic liver disease

HAV:Estimated prevalence High: Ab HAV >90% 10 years Very low: Ab HAV <50% 30 years Intermediate: Ab HAV > 50% 15 years and > 50% 30 years Hepatitis A virus seroprevalence by age and world region, 1990 and 2005.Jacobsen KH, Wiersma ST Vaccine. 2010 Sep 24; 28(41):6653-7.

Hepatitis notified cases in Argentina 1995-2004

Etiology of FHF in Argentina:1993-1999 100 patients Median age: 5.1 yrs old (1,1-15,8) Male 53/Female 47 90% < 10 yrs old Hepatitis A Indeterminate Toxic Autoimmune Ciocca M,Ramonet M,et al JPediatr Gastroenterol Nutr 31:1050(A)2000

Hepatitis A vaccine Inactivated are the most commonly used Highly effective Long term protection Licensed for use > 12 months of age Schedule: 0 - 6 monts

Argentina 2005: Single-dose vaccination strategy almost 100% of vaccinated individuals seroconvert 30 days after the first dose Experience of high efficacy of post –exposure prophylaxis for outbreak control with one dose The expectation that the natural booster induced by wild virus circulation could ensure long lasting protection The economic limitations in Argentina to include a 2-dose series

Vaccination Coverage

Hepatic Transplant in Argentina:1993-2013

Hepatitis A: Argentina 2000-2016 Universal Vaccination

Group A: Indirect estimation of HAV circulation in Argentina n=434 GroupB: Persistence of HAV Antibodies after 4 years of one dose of vaccine n=1059 Seroprevalence Ab-HAV before vaccination Journal of the Pediatric Infectious Disease Society, Vol 4, No 4 pp. e62-e67.2015

GMC: 170,5mIU/mL (95% CI: 163,2-178,2mIU/mL) The Pediatric Infectious Disease Journal.Vol 35,No 12,Dec 2016: 1339-1342

S320 OFID 2017: 4 (Supp 1) Poster ASbstracts n=1119 Mean age: 10,7 years old Mean post vaccination interval 9,7 years (Range 9,0-11,3 years) 87,6% had protective antibodies against HAV GMC 28,0 mIU/mL (95% CI: 26,8-29,3 mIU/mL) S320 OFID 2017: 4 (Supp 1) Poster ASbstracts

WHO Position paper on Hepatitis A vaccines 2012 WHO recommends Argentina’s 1 dose strategy A comparable option in terms on effectiveness Less expensive Easier to implement

Countries with Public Vaccination Programs HAV in America 2017

Thank you pelmassian@fidec-online.com