First year experience of rotavirus immunisation programme in Finland

Area of Science:

• Public Health
• Vaccinology
• Epidemiology

Background:

• Rotavirus (RV) immunisation programs aim to reduce the burden of acute gastroenteritis (AGE) and severe RV disease.
• Vaccine-probe studies estimate unspecific disease burden reduction attributable to the targeted agent.

Purpose of the Study:

• To estimate the impact of the rotavirus (RV) immunisation program on total hospital-treated AGE and severe RV disease burden in Finland.
• To assess the vaccine's effectiveness in the first year post-introduction.

Main Methods:

• Utilized the National Hospital Discharge Register data coded with ICD-10 codes (A00-A09, R11, K52).
• Compared incidences of hospitalised and outpatient cases of AGE and RVGE before (1999-2005) and after (2010) the immunisation program.
• Focused on children under 5 years of age.

Main Results:

• Significant reductions observed in hospital inpatient RV-associated gastroenteritis (RVGE) by 80.3% and total inpatient AGE by 53.9% in toddlers (<1 year).
• Hospital outpatient cases showed reductions of 78.8% in RVGE and 12.5% in total AGE.
• Overall vaccine impact against confirmed RVGE in eligible cohorts was 97%.

Conclusions:

• The RV immunisation program effectively controlled severe, hospital-treated RVGE in its first year.
• Total disease burden is a more reliable endpoint than diagnosed cases, as diagnostic practices evolve post-vaccination.
• The study's follow-up period was limited to the first post-introduction year.