Seroefficacy of Vi Polysaccharide–Tetanus Toxoid Typhoid Conjugate Vaccine (Typbar TCV)
| Autor: | Merryn Voysey, Andrew J. Pollard |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Adult
Male 0301 basic medicine Microbiology (medical) medicine.medical_specialty Adolescent 030106 microbiology Polysaccharide Vaccine Typhoid fever Young Adult 03 medical and health sciences Immunogenicity Vaccine 0302 clinical medicine Conjugate vaccine Internal medicine Tetanus Toxoid medicine Humans 030212 general & internal medicine Typhoid Fever Child Asymptomatic Infections Subclinical infection Vaccines Conjugate business.industry Tetanus Polysaccharides Bacterial Typhoid-Paratyphoid Vaccines Toxoid Infant Middle Aged Salmonella typhi medicine.disease Antibodies Bacterial Confidence interval Infectious Diseases Child Preschool Relative risk Female business |
| Zdroj: | Clinical Infectious Diseases. 67:18-24 |
| ISSN: | 1537-6591 1058-4838 |
| Popis: | Background Salmonella Typhi is the major cause of enteric fever in lower income countries. New conjugate vaccines show promise as public health interventions, however there are no efficacy data available from endemic areas. Methods Data were obtained from a previously published phase 3 randomised controlled trial comparing Vi-polysaccharide tetanus-toxoid conjugate vaccine (Typbar-TCV; Bharat Biotech Intl Ltd, India): (Vi-TT) with Vi-polysaccharide (Typbar; Bharat Biotech Intl Ltd, India): (Vi-PS) in participants aged 2- 45 years. An additional open-label arm administered Vi-TT to children aged 6 months to 23 months. The proportion of participants with presumed clinical or subclinical infection (‘seroincidence’), was determined using mixture models and compared using relative risks. Results 81/387 (21%) participants were classified as having presumed typhoid infection during the 2 year period post-vaccination. Seroincidence was lower in those randomised to Vi-TT than Vi-PS in those aged 2-45 years; 21/155 (13.5%) vs 47/129 (36.4%); RR 0.372 (95%CI 0.235–0.588), pConclusion This is the first field estimate of the seroefficacy of a Vi-TT vaccine and shows that Typbar TCV substantially reduces the number of serologically defined (sub)clinical infections in infants, children and adults. These results support the recent World Health Organisation recommendations for deployment of typhoid conjugate vaccines in high burden areas. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|