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Background: Vaccination in pregnancy with recombinant pertussis vaccine results in similar or higher antibody levels in infants compared with chemically detoxified acellular pertussis vaccine (Tdapchem). We evaluated antibody responses to primary childhood vaccination in infants born to mothers vaccinated in pregnancy with recombinant pertussis vaccine containing 1, 2 or 5 µg genetically detoxified pertussis toxin (ap1gen, Tdap1gen, Tdap2gen or TdaP5gen) or Tdapchem., Methods: Infants (393) received diphtheria-tetanus-whole cell pertussis (DTwP) at 2, 4 and 6 months (3+0) and 13-valent pneumococcal conjugate vaccine (PCV13) at 2, 4 and 12 months of age (2+1). Serum IgG levels against pertussis toxoid (PT), filamentous hemagglutinin (FHA), diphtheria toxoid (DT), tetanus toxoid (TT), PCV13 serotypes and PT-neutralizing antibody (PT-Nab) titers were assessed. PT-IgG ≥10 IU was used as a cutoff for potential protection in infants., Results: PT-IgG geometric mean concentrations (GMC) were ≥10 IU/mL at 5 and 7 months of age but waned below 10 IU/mL at 13 months in all groups. FHA-IgG GMCs and PT-Nab geometric mean titers were also below 10 IU/mL in all groups at 13 months of age. TT-IgG and DT-IgG seroprotection rates (≥0.1 IU/mL) ranged from 97.1% to 100% at 7 and 13 months. Postbooster PCV13-serotype-specific seroprotection rates (IgG ≥ 0.35 µg/mL) ranged between 87% and 100%. Antibody responses were comparable between groups after DTwP priming (7 months) and PCV13 priming (5 months) and booster vaccination (13 months)., Conclusions: Childhood vaccine responses are comparable after mothers receive genetically or chemically detoxified acellular pertussis vaccines in pregnancy., Competing Interests: C.K., V.Y., L.F., S.M. and H.T.P. are employed by BioNet. The remaining authors have no conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: This study investigated the immunogenicity and safety of a fully liquid, hexavalent, diphtheria (D)-tetanus (T)-whole-cell pertussis (wP)-inactivated poliovirus (IPV)-hepatitis B (HB)- Haemophilus influenzae b (PRP-T) vaccine compared to licensed DTwP-HB-PRP~T, IPV, and bivalent oral poliovirus (bOPV) vaccines following co-administration with other pediatric vaccines [pneumococcal conjugate vaccine (PCV13) and rotavirus vaccine]., Methods: Phase III, randomized, open-label study in Thailand. Healthy infants received DTwP-IPV-HB-PRP~T at 2, 4 and 6 months of age (N = 228), or DTwP-HB-PRP~T and bOPV (2, 4 and 6 months of age) and IPV (4 months of age) (N = 231). All participants received PCV13 (2, 4 and 6 months of age) and rotavirus vaccine (2 and 4 months of age). Immunogenicity for all antigens was assessed using validated assays, and noninferiority post-third dose was evaluated for anti-D, anti-T, anti-pertussis [anti-pertussis toxin (anti-PT) and anti-fimbriae 2/3 (anti-FIM)], anti-polio 1, 2, 3, anti-HB, and anti-PRP~T. Safety was assessed using parental reports., Results: Noninferiority was demonstrated for each antigen, and overall noninferiority of DTwP-IPV-HB-PRP~T versus DTwP-HB-PRP~T+bOPV+IPV was concluded. Similarity in each group was observed for the GMC ratio for antirotavirus antibodies (20.9 and 17.3, respectively) and anti-PCV13 antibodies (range: 8.46-32.6 and 7.53-33.1, respectively). Two serious adverse events were related to DTwP-IPV-HB-PRP~T (febrile convulsion and acute febrile illness) and 1 was related to DTwP-HB-PRP~T+bOPV+IPV (febrile seizure), but overall there were no safety concerns with similar rates of participants experiencing solicited (99.1% and 98.3%) and unsolicited (19.3% and 19.5%) adverse events in each group., Conclusions: This study confirmed the suitability of DTwP-IPV-HB-PRP~T primary series vaccination in combination with rotavirus and PCV13 vaccines., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Recent studies report delayed anti-HIV antibody clearance (seroreversion) among HIV-exposed uninfected infants that may affect diagnostic practices. We evaluated the age-specific seroreversion rates in Thailand., Methods: The medical records of HIV-exposed uninfected infants born in January 2000-December 2014 were reviewed. Anti-HIV seroreversion rates at 12, 18 and 24 months were analyzed in 3 periods according to the Thai National Guidelines of prevention of mother-to-child transmission of HIV: zidovudine with or without single dose nevirapine to all women (2000-2006), adding lamivudine plus nevirapine to zidovudine in women with CD4 count <200 cells/mm (2007-2009) and zidovudine plus lamivudine plus boosted lopinavir to all women (2010-2014). In 2013, the serologic test kit was changed from third- to fourth-generation (4G) assay. All the infants were formula fed., Results: Among 736 infants, the overall seroreversion rates at 12, 18 and 24 months of age were 59.38%, 94.57% and 100%, respectively. The seroreversion rates at 12 months of age declined from 68% in 2000-2006 and 65.9% in 2007-2009, to 42.9% in 2010-2014 (P = 0.001). Seroreversion rates at 18 months of age were more than 96.5% before 2013 and decreased to 79.1% in 2013-2014 (P = 0.001) with use of 4G. Multivariate analysis identified antepartum protease inhibitors treatment and the use of 4G testing as independent factors associated with delayed seroreversion., Conclusions: Anti-HIV seroreversion delay in HIV-exposed uninfected infants was associated with use of protease inhibitors and 4G HIV testing, complicating the interpretation to exclude perinatal HIV infection.

Background: HIV infection may alter immunologic response and the establishment of immune memory to infant hepatitis B virus (HBV) vaccination. This study aimed to determine the need to revaccinate perinatally HIV-infected Thai adolescents., Methods: Cross-sectional serologic tests for HBV, including hepatitis B surface antigen, anti-hepatitis B surface antibody (anti-HBs) and anti-hepatitis B core antibody (anti-HBc), were performed in perinatally HIV-infected adolescents. Adolescents having anti-HBs <100 mIU/mL with negative anti-HBc and immune reconstitution from highly active antiretroviral therapy (HAART) were revaccinated using regular (10 μg) 3-dose schedule given intramuscularly at 0-, 2- and 6-month intervals., Results: Of 193 adolescents who received 3-dose infant HBV vaccination, 6 were receiving HAART during vaccination, median (interquartile range) current age 14.5 (11.7-16.2) years, 7 (3.6%) had positive anti-HBc (indicating breakthrough infection), of which 4 (2%) had positive hepatitis B surface antigen (indicating chronic infection). Twenty-two (11.4%) adolescents had protective anti-HBs concentration >10 mIU/mL. Of 164 revaccinated adolescents, 142 (86.6%) had HIV viral load <40 copies/mL. Anti-HBs seroconversion rates >10 mIU/mL were 58.0% (94/162) after the first dose and 97.5% (158/162) after the third dose of revaccination. Forty-five (28%) subjects responded to the first dose with anti-HBs antibody ≥100 mIU/mL had a shorter median duration with CD4 count <15% than their counterparts (6.2 vs. 11.1 months; P = 0.049)., Conclusions: Only half of perinatally HIV-infected adolescents were able to elicit anti-HBs response with a single-dose HBV vaccine. Revaccination with 3-dose schedule is required in perinatally HIV-infected adolescents who did not initiate HAART at the time of infant vaccination.

This single-group study investigated the immunogenicity and safety of a booster dose of the recently licensed live attenuated chimeric Japanese encephalitis vaccine in 50 healthy children (1-5 years old) who were primed with the live attenuated SA14-14-2 vaccine. A strong anamnestic response was induced 28 days postbooster: geometric mean titer, 9144 (95% confidence interval: 7365-11353); and seroprotection rate, 49 of 49 (100%) children.

We assessed the prevalence of vitamin D deficiency among 101 perinatally HIV-infected Thai adolescents receiving antiretroviral therapy. Median age was 14.3 (interquartile range 13.0-15.7) years, and 90% had a HIV RNA<50 copies/mL. The median (interquartile range) 25-hydroxyvitamin D (25-OHD) level was 24.8 (6.9-46.9) ng/mL; 25 (24.7%) had vitamin D deficiency (25-OHD<20 ng/mL) and 47 (46.5%) had insufficiency (25-OHD 20-30 ng/mL). Adolescents with vitamin D deficiency had significantly higher parathyroid hormone levels (54.9 vs. 40.2 pg/mL, P<0.007). No associations between vitamin D deficiency and body mass index, bone mineral density, efavirenz use, HIV RNA, CD4 or self-reported sunlight exposure were observed.