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Background: Surveillance for adverse events following immunization (AEFI) is important to monitor vaccine safety and should lead to appropriate responses to improve health and immunization program. Bleeding following vaccination is not recognized as an important AEFI. Without policy of vitamin K (VK) prophylaxis at birth, vitamin K deficiency bleeding (VKDB) could be an important cause of bleeding in young infants and may manifest as AEFI., Methods: We retrospectively analysed all serious AEFI cases that presented with external or internal bleeding reported to Nepal's AEFI surveillance system during 2016-2018. The cases were classified as VKDB, suspected VKDB or non-VKDB., Results: During the period, 16 serious AEFI with symptom or sign of bleeding were reported representing 21.3% of all serious AEFI reported. Cases were between 40 and 94 days of age. The National AEFI Investigation Committee classified all cases as coincidental. Fourteen cases (87.5%) had bleeding from injection site. Median time from vaccination to injection site bleeding was 4.3 h (interquartile range: 2.1-11.6 h). Six cases (37.5%) had intra-cranial haemorrhage. Only one case had confirmed history of receiving VK at birth. Ten cases (62.5%) received appropriate treatment (VK injection; blood transfusion if needed). Based on limited laboratory investigations available, three cases (18.75%) could be classified as late onset VKDB and 11 cases (68.75%) as suspected late onset VKDB., Conclusion: VKDB should be suspected in young infants presenting with bleeding including following vaccination, and prompt treatment should be initiated. Bleeding following vaccination should be recognized as an important AEFI as even a small amount of blood loss in young infants can be catastrophic. We posit that this series is a small subset of VKDB cases in Nepal detected through AEFI surveillance system. In countries without policy of VK prophylaxis at birth including Nepal, the policy should be introduced., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. NA is the Chair of the National AEFI Investigation Committee (AEFI-IC). RP and ASB are WHO staff and are involved in providing technical assistance for field investigation of serious AEFI cases, and technical and secretarial assistance to the AEFI-IC. BST and JSG are government staff. JSG is member-secretary of the AEFI-IC., (Copyright © 2020. Published by Elsevier Ltd.)

Background: Haemophilus influenzae type b (Hib) carriage and disease studies in Nepali children suggest a significant burden of infection. Hib conjugate vaccines (HibCV) do not have uniform immunogenicity between populations. We determined the immunogenicity of HibCV in Nepali infants, before its introduction into the routine immunization schedule., Methods: Ninety infants recruited at Patan Hospital, Kathmandu, received 3 doses of the HibCV with routine immunizations (diphtheria, tetanus, whole cell pertussis-hepatitis B vaccine + oral polio vaccine) at 6, 10 and 14 weeks of age, and a HibCV booster at 52 weeks. Anti-polyribosylribitol phosphate (PRP) concentrations were measured at 18, 52 and 56 weeks, and the antibody persistence at 52 weeks was compared with antibody values in unimmunized controls (n = 30)., Results: After 3 doses of primary immunizations, at 18 weeks of age (n = 74), all infants had anti-PRP concentrations above the accepted thresholds for short- and long-term protection (0.15 and 1.0 µg/mL, respectively). At 1 year of age, before administration of the booster of HibCV, the anti-PRP geometric mean antibody concentration was 2.76 µg/mL (confidence interval: 1.88-4.07) in sera from the immunized children compared with 0.11 µg/mL (95% confidence interval: 0.08-0.17) in the nonimmunized control group (n = 30). Twenty-seven percent (20/74) of participants, however, had anti-PRP concentrations <1.0 µg/mL. Four weeks after the booster dose of HibCV, 98.5% of infants had anti-PRP concentrations above 1.0 µg/mL., Conclusion: Immunization with HibCV given as part of the Expanded Program on Immunization schedule in Nepal elicits robust antibody responses. Though the antibody wanes during the first year of life, most 1-year-old infants remain protected and respond robustly to a booster dose of the vaccine.

Background: Children are substantially affected by enteric fever in most settings with a high burden of the disease, including Nepal. However pathogen population structure and transmission dynamics are poorly delineated in young children, the proposed target group for immunization programs. Here we present whole genome sequencing and antimicrobial susceptibility data on 198 S. Typhi and 66 S. Paratyphi A isolated from children aged 2 months to 15 years of age during blood culture surveillance at Patan Hospital, Nepal, 2008–2016. Principal findings: S. Typhi was the dominant agent and comprised several distinct genotypes, dominated by 4.3.1 (H58). The heterogeneity of genotypes in children under five was reduced compared to data from 2005–2006, attributable to ongoing clonal expansion of H58. Most isolates (86%) were non-susceptible to fluoroquinolones, associated mainly with S. Typhi H58 Lineage II and S. Paratyphi A harbouring mutations in the quinolone resistance-determining region (QRDR); non-susceptible strains from these groups accounted for 50% and 25% of all isolates. Multi-drug resistance (MDR) was rare (3.5% of S. Typhi, 0 S. Paratyphi A) and restricted to chromosomal insertions of resistance genes in H58 lineage I strains. Temporal analyses revealed a shift in dominance from H58 Lineage I to H58 Lineage II, with the latter being significantly more common after 2010. Comparison to global data sets showed the local S. Typhi and S. Paratyphi A strains had close genetic relatives in other South Asian countries, indicating regional strain circulation. Multiple imports from India of ciprofloxacin-resistant H58 Lineage II strains were identified, but these were rare and showed no evidence of clonal replacement of local S. Typhi. Significance: These data indicate that enteric fever in Nepal continues to be a major public health issue with ongoing inter- and intra-country transmission, and highlights the need for regional coordination of intervention strategies. The absence of a S. Paratyphi A vaccine is cause for concern, given its prevalence as a fluoroquinolone resistant enteric fever agent in this setting. [ABSTRACT FROM AUTHOR]

Haemophilus influenzae type b (Hib) is now recognized as an important pathogen in Asia. To evaluate disease susceptibility, and as a marker of Hib transmission before routine immunization was introduced in Kathmandu, 71 participants aged 7 months–77 years were recruited and 15 cord blood samples were collected for analysis of anti-polyribosylribitol phosphate antibody levels by enzyme-linked immunosorbent assay. Only 20% of children under 5 years old had levels considered protective (>0.15 µg/ml), rising to 83% of 15–54 year-olds. Prior to introduction of Hib vaccine in Kathmandu, the majority of young children were susceptible to disease. [ABSTRACT FROM AUTHOR]