Procedures
deaths, acute flaccid paralysis, vaccine-associated
VIRAL DISEASES, ADVERSE EVENTS, ENCEPHALITIS, POLIO, ASEPTIC MENINGITIS, ADVERSE EVENT, DISEASE, POLIO
Infants in the nOPV2 group received a vaccine (PT Bio Farma, Indonesia) composed of an attenuated serotype 2 poliovirus derived from a modified Sabin 2 infectious clone propagated in Vero cells.The first vaccine or placebo dose was given within a window of 0–3 days after birth and all participants received a second dose of their assigned vaccine or placebo 4 weeks after the first dose. Because this was the first planned use in newborn infants, study administrations were first given to 30 participants in a blinded manner (20 [67%] participants with nOPV2 and ten [33%] participants with placebo) and the safety data from these participants were reviewed by the data and safety monitoring board before approval to continue vaccination of the remaining infants.Following vaccine or placebo administration participants were observed for 30 min to record any immediate reaction or adverse event. After each vaccination study staff visited participants' homes daily for 7 days to record in electronic diaries solicited systemic adverse events. Mothers of participants were provided with a telephone number to communicate with the investigator or study staff to report any serious adverse events and weekly study visits were continued throughout the study duration to collect and record any reports of unsolicited adverse events, serious adverse events, or adverse events of special interest, notably anaphylactic reactions, aseptic meningitis or encephalitis, unexplained deaths, or acute flaccid paralysis due to cVDPV or vaccine-associated paralytic polio. The intensity of any recorded solicited or unsolicited adverse event was assessed by the investigator using a standard grading scheme (Before the vaccine administrations at birth and 4-week visits, 1-mL blood samples were drawn and kept refrigerated (2–8°C) during shipping to the icddr,b Matlab laboratory, where sera were prepared within 24 h. Serum aliquots were stored at –20°C and shipped to the Polio and Picornavirus Laboratory of the Division of Viral Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA for measurement of neutralising antibodies against the three polio types by microneutralisation assay. Antibody titres below 1:8 were considered non-detectable and the highest reported reciprocal titre was calculated as at least 1:1448 (10·5 logMothers were asked to collect samples of approximately 8 g of stool at birth and at 2, 4, 6, 8, 10, and 12 weeks during the study (