Fig. 4

Odds ratios (95 % CIs) of influenza vaccine effectiveness during influenza seasons (black square), during pre-influenza seasons (striped circle) and post-influenza seasons (white circle) against hospitalization due to influenza or pneumonia (a), hospitalization for acute coronary syndrome (b), hospitalization due to cardiovascular diseases (c), influenza-like illness (d), prematurity (e), small for gestational age (f), and medically attended respiratory illness in infants (g)