Outcomes
ADVERSE EVENTS, DECAY, SECONDARY, VIRAL SHEDDING
The coprimary objectives were to assess the safety and tolerability, and the immunogenicity (measured by seroconversion rate) after one and two doses of nOPV2 when given 4 weeks apart in poliovirus vaccine-naive newborn infants. The secondary outcome was an assessment of the rate, duration, and extent of faecal viral shedding measured by real-time RT-PCR.The safety and tolerability objective was assessed as the incidence rates of solicited adverse events in the 7 days after each vaccination, and unsolicited adverse events, serious adverse events, and adverse events of special interest over the entire study duration, with comparison between nOPV2 and placebo groups. The primary immunogenicity outcome was the seroconversion rate for neutralising antibodies against type 2 poliovirus measured 28 days after the first and second vaccinations with nOPV2. We defined the seroconversion rate cumulatively as the proportions for each group who either (1) became seropositive (≥1:8 titre) after being seronegative (<1:8) at baseline, or (2) had a four-fold or greater increase above the predicted titre in baseline seropositive participants. The predicted titre was calculated assuming an exponential decay from baseline with a half-life of 28 days.