Maternal Immunization in Argentina: Nationwide Strategy

Abstract

Background: Immunization against flu and pertussis is prioritized within the comprehensive care strategy for pregnant women (PW) and small infants in Argentina. Flu vaccine was included in the National Immunization Schedule (NIS) in 2011. Argentina recommended a vaccination strategy for PW against pertussis in 2012, with the aim of reducing complications and deaths related to both diseases. Objective: To describe the national strategy of maternal immunization, January 2011- October 2017. Methods & Materials: Descriptive study. National vaccination coverages (NVC) between 2011-2017, lethality rates and vaccines safety profile were analyzed. Adverse events following immunization (AEFI) notifications were performed passively. Rates (R) are expressed in 100,000 doses. Results: Between 2011-2017, 2,540,601 doses of flu vaccine were applied (NVC >95% most years). There were no notifications of influenza related deaths in vaccinated PW during this period. There were 16 notified AEFI (R 0.6): 6 vaccine related reactions (5 mild, 1 severe*); 5 program errors; a case of flaccid paralysis classified as non-conclusive event due to lack of complementary studies. In 2012, Tdap was recommended after the 20th gestation week. Between 2012-2017, 2,557,432 doses were applied. NVC 2012-2016 were 50.9%, 67.1%, 70.9%, 61.7%, 65.3%, respectively. 47 AEFI were reported (R:1.8), 12 vaccine related (1 severe*) and 1 anxiety disorder. Program errors were 31 (66%; R:1.2). Comparing previous and post vaccination strategy, the global pertussis lethality rate dropped 68.8% (p < 0.001) globally and 84.1% (p < 0.001) in infants less than 2 months. *The notified severe reaction vaccine was a case of Guillain-Barre syndrome after flu and Tdap vaccination, without sequelae. It was not possible to attribute the AEFI to one particular vaccine. Conclusion: Argentina became the first Latin-American country to set a strategy of vaccination against pertussis universally. Since 2012 a downward trend in pertussis mortality was evident and no deaths from influenza in vaccinated were notified in PW. The adequate safety profile of both vaccines in PW is reassuring.