<p>N: Number of deaths; P-d: Person-days at risk; RR adj: adjusted Rate Ratio; CI: Confidence Interval.</p>1<p>RRs are estimated by the Poisson regression model and adjusted by age group (31–80; 81–100; 101–120; 121–180; 181–360; 361–729).</p>2<p>The information of the brand name of the hexavalent product was missing for 1 infant (the event occurred in the control period).</p