Background And Objective: Shigella conjugate vaccines have been shown to be safe, immunogenic and efficacious in adult volunteers. We have now investigated the safety and immunogenicity of investigational Shigella sonnei and Shigella flexneri 2a conjugate vaccines in 1- to 4-year-old children, the age group at greatest risk for shigellosis.

Methods: The O-specific polysaccharides of S. sonnei and S. flexneri 2a, the two most common shigellae from patients in Israel, were bound to medically useful carrier proteins to form conjugates. Eighty healthy 1- to 4-year-olds were randomized to receive two 0.5-ml im injections 6 weeks apart of either S. sonnei-CRM(9) or S. flexneri 2a-rEPA(succ). Blood was taken before, 6 weeks after the first injection, 4 weeks after the second injections and 2 years after immunization for assay of IgG anti-lipopolysaccharide, diphtheria toxin and Pseudomonas aeruginosa exotoxin A antibodies by enzyme-linked immunosorbent assay.

Results: During an 8-day surveillance period after each immunization, low fever (37.8-39.0 degrees C) lasting only 24 to 48 h occurred in 2 of 40 recipients after the first injection and 4 of 40 recipients after the second injection of S. flexneri 2a-rEPA(succ) and in 2 of 38 of S. sonnei-CRM(9) after the second injection; no fever was detected after the first injection. Liver function tests were normal in all vaccinees. S. sonnei-CRM(9) elicited a >4-fold rise in IgG anti-LPS in 92.1% and S. flexneri 2a-rEPA(succ) in 85% (P < 0.0001) after the second injection; both conjugates elicited type-specific booster responses. At 2 years the geometric mean concentrations of both IgG anti-lipopolysaccharides were significantly higher than preimmunization levels. A >4-fold rise of IgG anti-diphtheria (65.8%) and IgG anti-ETA (77.5%) was observed.

Conclusion: These experimental Shigella conjugate vaccines were safe and immunogenic in 1- to 4-year-old children.

Download full-text PDF

Source
http://dx.doi.org/10.1097/01.inf.0000078156.03697.a5DOI Listing

Publication Analysis

Top Keywords

conjugate vaccines
16
flexneri 2a-repasucc
12
second injection
12
safety immunogenicity
8
shigella flexneri
8
shigella conjugate
8
vaccines safe
8
safe immunogenic
8
4-year-old children
8
>4-fold rise
8

Similar Publications

To investigate the safety of the tetravalent meningococcal conjugate vaccine (MPCV-ACYW) in combination with the inactivated poliomyelitis (IPV) vaccine and diphtheria-tetanus-acellular pertussis (DTaP) vaccine for infants aged 3-5 months and provide real-world evidence for the immunization strategy of vaccine combination. From June to October 2023, a total of 600 3-month-old infants were selected and divided into three groups: control group, mono-vaccination group and combined vaccination group. They were simultaneously or individually vaccinated with MPCV-ACYW, IPV and DTaP vaccines at 3, 4, and 5 months of age, respectively.

View Article and Find Full Text PDF

The AEP 2025 Vaccination and Immunization Schedule recommended for children, adolescents and pregnant women residing in Spain features the following novelties: Due to the increase in measles cases and outbreaks in recent years, we recommend advancing the second dose of measles, mumps and rubella (MMR) vaccine to 2 years of age. As a consequence of the above, since many autonomous communities (ACs) use the quadrivalent vaccine for the second dose of MMR and varicella vaccines, we recommend, for all ACs, advancing the second dose of varicella vaccine to 2 years of age. Due to the very significant increase in cases of pertussis since late 2023 and especially in 2024, we recommend advancing the dose of Tdap given in adolescence to 10-12 years of age.

View Article and Find Full Text PDF

Purpose: None of the antibody-drug conjugates (ADCs) targeting Claudin 18.2 (CLDN18.2) have received approval from regulatory authorities due to their limited clinical benefits.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!