Higher Tetanus Toxoid Immunity 2 Years After PsA-TT Introduction in Mali.

Abstract

BACKGROUND:

In 2010, mass vaccination with a then-new meningococcal A polysaccharide-tetanus toxoid protein conjugate vaccine (PsA-TT, or MenAfriVac) was undertaken in 1- to 29-year-olds in Bamako, Mali. Whether vaccination with PsA-TT effectively boosts tetanus immunity in a population with heterogeneous baseline tetanus immunity is not known. We assessed the impact of PsA-TT on tetanus toxoid (TT) immunity by quantifying age- and sex-specific immunity prior to and 2 years after introduction.

METHODS:

Using a household-based, age-stratified design, we randomly selected participants for a prevaccination serological survey in 2010 and a postvaccination survey in 2012. TT immunoglobulin G (IgG) antibodies were quantified and geometric mean concentrations (GMCs) pre- and postvaccination among all age groups targeted for vaccination were compared. The probability of TT IgG levels ≥0.1 IU/mL (indicating short-term protection) and ≥1.0 IU/mL (indicating long-term protection) by age and sex was determined using logistic regression models.

RESULTS:

Analysis of 793 prevaccination and 800 postvaccination sera indicated that while GMCs were low pre-PsA-TT, significantly higher GMCs in all age-sex strata were observed 2 years after PsA-TT introduction. The percentage with short-term immunity increased from 57.1% to 88.4% (31.3-point increase; 95% confidence interval [CI], 26.6-36.0;, P < .0001) and with long-term immunity increased from 20.0% to 58.5% (38.5-point increase; 95% CI, 33.7-43.3; P < .0001) pre- and postvaccination.

CONCLUSIONS:

Significantly higher TT immunity was observed among vaccine-targeted age groups up to 2 years after Mali's PsA-TT mass vaccination campaign. Our results, combined with evidence from clinical trials, strongly suggest that conjugate vaccines containing TT such as PsA-TT should be considered bivalent vaccines because of their ability to boost tetanus immunity.

• Authors: Nicole E Basta, Ray Borrow, Abdoulaye Berthe, Uma Onwuchekwa, Awa Traoré Eps Dembélé, Rachael Almond, Sarah Frankland, Sima Patel, Daniel Wood, Maria Nascimento, Olivier Manigart, Caroline L Trotter, Brian Greenwood, Samba O Sow
• Journal: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (Clin Infect Dis) Vol. 61 Suppl 5 Pg. S578-85 (Nov 15 2015) ISSN: 1537-6591 [Electronic] United States
• PMID: 26553691 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Chemical References

• Antibodies, Bacterial
• Immunoglobulin G
• MenAfriVac
• Meningococcal Vaccines
• Tetanus Antitoxin
• Tetanus Toxoid

Topics

• Adolescent
• Adult
• Antibodies, Bacterial (blood)
• Child
• Child, Preschool
• Female
• Humans
• Immunoglobulin G (blood)
• Infant
• Infant, Newborn
• Male
• Mali
• Meningococcal Vaccines (administration & dosage, immunology)
• Tetanus Antitoxin (blood)
• Tetanus Toxoid (immunology)
• Young Adult