TY - JOUR
T1 - Longevity of serologic responses following a single dose of typhoid conjugate vaccine among children living with HIV in Pakistan
T2 - A prospective cohort study
AU - Batool, Rabab
AU - Yousafzai, Mohammad Tahir
AU - Mir, Fatima
AU - Muhammad, Sajid
AU - Shaikh, Saqib Ali
AU - Memon, Sikander
AU - Qamar, Farah Naz
N1 - Publisher Copyright:
© 2024
PY - 2024/9/17
Y1 - 2024/9/17
N2 - Background: This study aimed to assess the longevity of serologic response and seroconversion rates at several time points following TCV vaccination among children living with HIV aged 6 months to 15 years in Pakistan. Methods: From November 20, 2020, to January 2, 2021; 336 children were enrolled and followed up prospectively for 12 months. Blood samples were collected before the administration of TCV and at 4–6 weeks, 6 months, and 1 year after administration of a single dose (0.5 ml) of intramuscular Typbar TCV®. Samples were analyzed for anti-Vi-IgG antibodies using ELISA. Geometric mean titers (GMTs), seroconversion rates (fourfold rise in anti-Vi-IgG from baseline) were assessed, and factors associated with sustained seroconversion at 1 year were evaluated using generalized linear mixed models. Findings: The seroconversion rates were significantly lower in children aged 6 months to 5 years compared to children > 5 years; (127/216 (58·8%)) versus (81/111 (73·0%)) at 6 months and (110/217 (50·7%)) versus (78/109 (71·6%)) at 1 year, only two-third; 188/326 (57·7%) remained seroconverted at 1 year. The GMTs (95 % CI) were significantly lower in children aged 6 months to 5 years compared to children > 5 years, 9·6 (7·6, 12·0) versus 28·9 (20·2, 41·4) at 6 months, and 6·6 (5·4, 8·0) versus 23·1 (16·4, 32·5) at 1 year time point. The odds of sustained seroconversion significantly decreased with time (adjusted odds ratio (aOR): 0.23; 95 % CI: 0.14, 0.40). The odds of sustained seroconversion following 1 year of TCV vaccination were significantly higher among children with non-severe HIV clinical disease (aOR: 10·61; 95% CI: 1·52, 73·98) and children in elder age group (aOR: 7·45; 95% CI: 1·18, 47·03). Conclusions: A significant decrease in seroconversion rates was observed among children living with HIV following one year of TCV administration. The decline was significantly higher in children with severe or advanced HIV clinical disease and children younger than five years of age.
AB - Background: This study aimed to assess the longevity of serologic response and seroconversion rates at several time points following TCV vaccination among children living with HIV aged 6 months to 15 years in Pakistan. Methods: From November 20, 2020, to January 2, 2021; 336 children were enrolled and followed up prospectively for 12 months. Blood samples were collected before the administration of TCV and at 4–6 weeks, 6 months, and 1 year after administration of a single dose (0.5 ml) of intramuscular Typbar TCV®. Samples were analyzed for anti-Vi-IgG antibodies using ELISA. Geometric mean titers (GMTs), seroconversion rates (fourfold rise in anti-Vi-IgG from baseline) were assessed, and factors associated with sustained seroconversion at 1 year were evaluated using generalized linear mixed models. Findings: The seroconversion rates were significantly lower in children aged 6 months to 5 years compared to children > 5 years; (127/216 (58·8%)) versus (81/111 (73·0%)) at 6 months and (110/217 (50·7%)) versus (78/109 (71·6%)) at 1 year, only two-third; 188/326 (57·7%) remained seroconverted at 1 year. The GMTs (95 % CI) were significantly lower in children aged 6 months to 5 years compared to children > 5 years, 9·6 (7·6, 12·0) versus 28·9 (20·2, 41·4) at 6 months, and 6·6 (5·4, 8·0) versus 23·1 (16·4, 32·5) at 1 year time point. The odds of sustained seroconversion significantly decreased with time (adjusted odds ratio (aOR): 0.23; 95 % CI: 0.14, 0.40). The odds of sustained seroconversion following 1 year of TCV vaccination were significantly higher among children with non-severe HIV clinical disease (aOR: 10·61; 95% CI: 1·52, 73·98) and children in elder age group (aOR: 7·45; 95% CI: 1·18, 47·03). Conclusions: A significant decrease in seroconversion rates was observed among children living with HIV following one year of TCV administration. The decline was significantly higher in children with severe or advanced HIV clinical disease and children younger than five years of age.
KW - HIV
KW - Salmonella Typhi
KW - Seroconversion
KW - Typhoid conjugate vaccine
UR - http://www.scopus.com/inward/record.url?scp=85194571616&partnerID=8YFLogxK
U2 - 10.1016/j.vaccine.2024.05.057
DO - 10.1016/j.vaccine.2024.05.057
M3 - Article
AN - SCOPUS:85194571616
SN - 0264-410X
VL - 42
JO - Vaccine
JF - Vaccine
IS - 22
M1 - 126009
ER -
