Hin the prior 3 months, and the most commonly reported was abdominal pain (10.9 ). In addition, 11 subjects (23.9 ) had at least 1 concurrent medical condition. The mean gestational age at which the vaccine was administered was 29.0 weeks. Of the 46 subjects, it was the first pregnancy for 24 (52.2 ), and their mean age was 30.3 years old. Among the subjects with previous pregnancies (n = 22), 11 had prior vaginal deliveries and 10 cesarean sections. One subject had a baby with congenital heart disease. No complications during previous pregnancies and/ or deliveries were reported. All 46 subjects had live births, and no birth defects were noted in any infants. The majority of the study subjects (93.2 ) did not report any complications during delivery, and the mean gestational age at ASP015K delivery was 38.8 weeks. One subject, P030, experienced premature rupture of membranes, placenta previa, and fetal distress, and 2 subjects, P017 and P031, experienced a prolonged labor during delivery. Twenty-seven subjects (61.4 ) gave birth via unassisted vaginal delivery, 16 subjects (36.4 ) received a cesarean section, and 1 subject (2.3 ) required vacuum assistance during vaginal delivery. Among the 44 infants, 25 infants (56.8 ) were boys and 19 (43.2 ) were girls. The mean height was 49.6 cm, the mean head circumference was 33.9 cm, and the mean weight was 3175.3 g. The majority of the infants (95.5 ) had an Apgar score of 9 at 1 min and 100 of the infants had an Apgar score 9 at 5 min. Blood samples were obtained before and 4 weeks (28 days) after vaccination from 46 subjects. Samples were obtained from 44 subjects at the time of delivery, and 42 cord blood samples wereData presented as number (percentage). doi:10.1371/journal.pone.0062983.twomen. Pregnancy outcomes including the type of delivery were recorded. Infant information including birth length, weight, sex, Apgar score at 1 min and 5 min, and other information specified in the medical chart were collected. The occurrence of adverse events was monitored for 8 weeks after delivery.Laboratory assaysMedChemExpress BIBS39 hemagglutination inhibition (HAI) assays was performed at the Adimmune Corporation designated central laboratory, and validated according to international standards. Antigens including A/California/7/2007, A/Perth/16/2009, and B/Brisbane/60/ 2008, were provided by Adimmune Corporation and were prepared by inactivating the whole virus with formalin. Reference antiserum to A/California/7/2009, A/Perth/16/2009, and B/ Brisbane/60/2008 were obtained from the National Institute for Biological Standards and Control (NIBSC). Serum samples were treated with receptor-destroying enzymes to eliminate nonspecific hemagglutination inhibitors. Each sample was tested in duplicate an initial dilution of 1:10. All laboratory personnel were blinded to the sample identity. For the purposes of calculation, samples with the titer of ,1:10 (negative) were assigned a titer of 1:5.Statistical analysisThe 3 co-primary immunologic endpoints were seroprotection (HI titer .40), seroconversion (.4-fold increase in titer from baseline and post-vaccination HI titer .40 if the baseline titer was ,10), and fold increase in geometric mean titer (GMT). Continuous variables were expressed as mean 6 SD, whileInfluenza Vaccination in Pregnancycollected. The baseline seropositive rate against H1N1, H3N2, and influenza B virus was 41.3 , 52.2 , and 43.5 , respectively. The baseline seroprotection rate against H1N1, H3N2, and influenza B.Hin the prior 3 months, and the most commonly reported was abdominal pain (10.9 ). In addition, 11 subjects (23.9 ) had at least 1 concurrent medical condition. The mean gestational age at which the vaccine was administered was 29.0 weeks. Of the 46 subjects, it was the first pregnancy for 24 (52.2 ), and their mean age was 30.3 years old. Among the subjects with previous pregnancies (n = 22), 11 had prior vaginal deliveries and 10 cesarean sections. One subject had a baby with congenital heart disease. No complications during previous pregnancies and/ or deliveries were reported. All 46 subjects had live births, and no birth defects were noted in any infants. The majority of the study subjects (93.2 ) did not report any complications during delivery, and the mean gestational age at delivery was 38.8 weeks. One subject, P030, experienced premature rupture of membranes, placenta previa, and fetal distress, and 2 subjects, P017 and P031, experienced a prolonged labor during delivery. Twenty-seven subjects (61.4 ) gave birth via unassisted vaginal delivery, 16 subjects (36.4 ) received a cesarean section, and 1 subject (2.3 ) required vacuum assistance during vaginal delivery. Among the 44 infants, 25 infants (56.8 ) were boys and 19 (43.2 ) were girls. The mean height was 49.6 cm, the mean head circumference was 33.9 cm, and the mean weight was 3175.3 g. The majority of the infants (95.5 ) had an Apgar score of 9 at 1 min and 100 of the infants had an Apgar score 9 at 5 min. Blood samples were obtained before and 4 weeks (28 days) after vaccination from 46 subjects. Samples were obtained from 44 subjects at the time of delivery, and 42 cord blood samples wereData presented as number (percentage). doi:10.1371/journal.pone.0062983.twomen. Pregnancy outcomes including the type of delivery were recorded. Infant information including birth length, weight, sex, Apgar score at 1 min and 5 min, and other information specified in the medical chart were collected. The occurrence of adverse events was monitored for 8 weeks after delivery.Laboratory assaysHemagglutination inhibition (HAI) assays was performed at the Adimmune Corporation designated central laboratory, and validated according to international standards. Antigens including A/California/7/2007, A/Perth/16/2009, and B/Brisbane/60/ 2008, were provided by Adimmune Corporation and were prepared by inactivating the whole virus with formalin. Reference antiserum to A/California/7/2009, A/Perth/16/2009, and B/ Brisbane/60/2008 were obtained from the National Institute for Biological Standards and Control (NIBSC). Serum samples were treated with receptor-destroying enzymes to eliminate nonspecific hemagglutination inhibitors. Each sample was tested in duplicate an initial dilution of 1:10. All laboratory personnel were blinded to the sample identity. For the purposes of calculation, samples with the titer of ,1:10 (negative) were assigned a titer of 1:5.Statistical analysisThe 3 co-primary immunologic endpoints were seroprotection (HI titer .40), seroconversion (.4-fold increase in titer from baseline and post-vaccination HI titer .40 if the baseline titer was ,10), and fold increase in geometric mean titer (GMT). Continuous variables were expressed as mean 6 SD, whileInfluenza Vaccination in Pregnancycollected. The baseline seropositive rate against H1N1, H3N2, and influenza B virus was 41.3 , 52.2 , and 43.5 , respectively. The baseline seroprotection rate against H1N1, H3N2, and influenza B.
