Immunogenicity of a 24-Valent Klebsiella Capsular Polysaccharide Vaccine and an Eight-Valent Pseudomonas O-Polysaccharide Conjugate Vaccine Administered to Victims of Acute Trauma

We measured the antibody response in 10 victims of acute blunt trauma and penetrating trauma who were immunized against Klebsiella pneumoniae and Pseudomonas species within 72 hours of injury. The two vaccines, which were previously shown to be safe and immunogenic in uninjured humans, were a 24-valent K. pneumoniae capsular polysaccharide vaccine and an eight-valent Pseudomonas a-polysaccharide-toxin A conjugate vaccine. The patients were between 18 and 44 years of age, had Injury Severity Scores that ranged between 9 and 34, and did not have chronic infections or malignancies. On days 14 and 28 after immunization, all patients had a response of greater than fourfold to at least six of the nine Pseudomonas vaccine antigens. Half of the patients responded to eight of the nine antigens. Nine patients responded to at least 18 of 24 Klebsiella antigens, and seven patients responded to 22 of the 24 antigens. No important side effects were attributed to the vaccines. The results of this preliminary study indicate that active immunization against potential pathogens is possible in victims of acute traum

Safety and Immunogenicity of Live Oral Cholera and Typhoid Vaccines Administered Alone or in Combination with Antimalarial Drugs, Oral Polio Vaccine, or Yellow Fever Vaccine

The effects of concomitant administration of antimalarial drugs, oral polio vaccine, or yellow fever vaccine on the immune response elicited by the Vibrio cholerae CVD103-HgR and Salmonella typhi Ty21a live oral vaccines were investigated. Healthy adults were immunized with CVD103- HgR alone or combined with Ty21a. Subjects were randomized to simultaneously receive mefloquine, chloroquine or proguanil, or oral polio or yellow fever vaccine. The vibriocidal antibody seroconversion rate was significantly reduced (P = .008) only in the group that received chloroquine with the CVD103-HgR. The geometric mean vibriocidal antibody titer was significantly decreased in the groups that received chloroquine (P = .001) or mefloquine (P = .02) compared with titers in groups that received CVD103-HgR alone. However, similar immunosuppressive effects were not observed in the groups immunized with Ty21a and CVD103-HgR. Only the concomitant administration of proguanil effected a significant (P = .013) decline in the anti-S. typhi lipopolysaccharide antibody response. These results indicate that chloroquine and proguanil should not be simultaneously administered with the CVD103-HgR and Ty21a vaccine strains, respectivel

Affinity Constants of Naturally Acquired and Vaccine-Induced Anti-Pseudomonas aeruginosa Antibodies in Healthy Adults and Cystic Fibrosis Patients

Naturally acquired anti-Pseudomonas aeruginosa antibody fails to afford protection against repeated P. aeruginosa bronchopulmonary exacerbations in cystic fibrosis (CF) patients. In an effort to explain this phenomenon, the titer and affinity constants of serum anti-lipopolysaccharide (LPS) IgG were determined in five study groups: healthy adults before and after immunization with a polyvalent LPS-based vaccine, healthy noncolonized CF patients before and after immunization, nonimmunized CF patients with significantly elevated anti-LPS antibody titers without documented colonization, recently colonized CF patients before and after immunization, and nonimmunized CF patients chronically colonized with P. aeruginosa. Immunization elicited a significant rise in total anti-LPS immunoglobulin levels and affinity constants in both healthy adults and CF patients. Although chronically colonized patients had elevated levels of total anti-LPS antibody, these antibodies possessed affinities at least tOO-fold less than those of vaccine-induced antibodie

Immunization of Noncolonized Cystic Fibrosis Patients against Pseudomonas aeruginosa

The long-term safety and immunogenicity of a polyvalent Pseudomonas aeruginosa conjugate vaccine was evaluated in 30 noncolonized cystic fibrosis patients. Four doses were administered over 3 years, and patients were followed for a mean of 38 months. No acute or long-term adverse effects were noted. Immunization engendered a significant antibody response to all vaccine components. A decline in titers during year 3 of observation was associated with a marked rise in the isolation of P. aeruginosa. This organism was isolated repeatedly from the respiratory tract of 4 patients and only once from 7 patients. The remaining patients were repeatedly culture-negative. Only 1 patient showed clinical deterioration associated with multiple isolations of P. aeruginos

Onset and Duration of Protective Immunity in Challenged Volunteers afterVaccination with Live Oral Cholera Vaccine CVD l03-HgR

CVD 103-HgR is a liveoral cholera vaccinethat, in phase I and II studies to date, has been well tolerated and immunogenic. In challenge studies of US volunteers conducted 4-5 weeks after vaccination, CVD 103-HgR provided significant protection against experimental cholera due to classical and El Tor Vibrio cholerae O1. To determine the onset and duration of protection, two volunteer challenge studies were conducted: the first, 6 months after vaccination and the second, 8 days after vaccination. In both studies, CVD 103-HgR was 100% protective against diarrhea and significantly reduced the rate of shedding of vibrios after challenge with V.cholerae classical Inaba strain 569B, the virulent parent strain of CVD 103-HgR. Previously vaccinated subjects were less likely than naive controls to develop rises in titer of vibriocidal antibodies after challenge (P = .002), and the mean peak titer of vibriocidalantibodies was less than among controls. CVD 103-HgR can provide homologous protective immunity as soon as 8 days after vaccination and protection can persist for at least 6 month

Safety and Immunogenicity of Live Oral Cholera Vaccine Candidate CVD 110, a ΔctxA ctxAzot zotace Derivative of El Tor Ogawa Vibrio cholerae

The current pandemic of cholera is caused primarily by Vibrio cholerae O1 of the El Tor biotype. Live attenuated classical biotype V. cholerae vaccinestrains prevent severeand moderate cholera due to either biotype in challenged volunteers but may provide less protection against mild cholera due to El Tor organisms. CVD 110, a new ctxA-deleted vaccine strain derived from an El Tor Ogawa parent, lacks zona occludens toxin (Zot), accessorycholera enterotoxin (Ace), and hemolysin/enterotoxin. Ten healthy adult volunteers were given 108 cfu of CVD 110 with buffer;7 developed diarrhea (mean stool volume, 861 mL). Vaccine organisms wereshed in stool by all vaccinees and were recovered from duodenal fluid in three-quarters of vaccinees. After vaccination, the geometric mean peak reciprocal vibriocidal titer among vaccinees was 17,829. CVD 110 is a powerful immunogen but insufficiently attenuated despite the absence of known potential enterotoxins of V. cholerae. Another unrecognized toxin or colonization alone may be responsible for diarrhea after ingestion of this strai

Formulation development of a recombinant protein based non-replicating rotavirus (NRRV) vaccine candidate: Antigen-adjuvant-preservative interactions

Rotavirus is the leading cause of acute diarrhea and gastroenteritis among infants and young children worldwide. Over 215,000 children under five years of age die from rotavirus infection each year, mostly in developing world1. Currently two live attenuated oral rotavirus vaccines are available globally (Rotarix® and RotaTeq®) to reduce the burden of this disease with an efficacy of \u3e90% in developed countries2. Vaccine efficacy is lower, however, in developing countries due to a variety of factors3. To this end, a non-replicating rotavirus (NRRV) vaccine candidate, containing three recombinant protein antigens (P2-VP8-P[4], P2-VP8-P[6] and P2-VP8-P[8]), is being developed by PATH and its partners as a trivalent vaccine for use in the developing world4. This trivalent rotavirus vaccine candidate includes the three antigens from the most prevalent serotypes associated with \u3e90% of rotavirus gastroenteritis worldwide. In the present study, the following formulation development issues were examined: (1) establish stability-indicating physicochemical assays for a NRRV protein antigen (P[8]) bound to an aluminum hydroxide adjuvant (Alhydrogel®), which include primary and higher-order structures, chemical and conformational stability of the protein on Alhydrogel, and the ability to desorb the antigen from Alhydrogel; (2) examine the adsorptive capacity and coefficients of Alhydrogel® for the P[8] antigen in several candidate drug product formulations; (3) investigate the effects of binding to Alhydrogel® and the addition of two antimicrobial preservatives (2-phenoxyethanol or thimerosal) on the structural integrity and conformational stability of P[8], the latter of which were found to be potent destabilizers of the antigen; and (4) monitor the real-time and accelerated storage stability over 3 months of P[8] bound to Alhydrogel® in several candidate formulations with and without thimerosal at different temperatures. In the absence of preservative, the P[8] protein antigen was overall stable with only a small amount of Asn deamidation observed in samples stored under real-time (4˚C) or accelerated (25˚C) temperatures. Similarly, little (if any) changes were observed in the real-time stability of the antigen on Alhydrogel® in the presence of thimerosal. Under accelerated storage temperatures (25 or 37˚C) however, the preservative caused an increase in inter-molecular disulfide bonding, decrease of apparent enthalpy as measured by DSC, and a decrease in in-vitro antigenicity. Similar stability studies are currently ongoing with the P[4] and P[6] protein antigens. Acknowledgements: Funding provided by the Bill & Melinda Gates Foundation References: 1. Tate et al 2016. Clinical Infectious Diseases 62:S96-S105 2. Tissera et al. 2017. Human Vaccines & Immunotherapeutics 13(4):921-927 3. Glass et al. 2014. Journal of Infection 68: S9-S18. 4. Groome et al. 2017. Lancet Infectious Diseases17(8): 843-853

Detection of Enterobacterial Lipopolysaccharides and Experimental Endotoxemia by Means of an Immunolimulus Assay Using Both SerotypeSpecific and Cross-Reactive Antibodies

The immunolimulus (IML) assay system uses solid-phase endotoxin antibodies to capture lipopolysaccharide (LPS), which is then quantified by a modification of the chromogenic limulus amebocyte lysate (CLAL) method. Monoclonal antibodies (MAbs) reactive with selected 0 antigen serotypes of Escherichia coli (O18) and Salmonella typhimurium (O-9,12), when used in the IML, were shown to be highly specific in detecting their respective endotoxins in purified form and in plasma samples from experimentally infected animals. A murine MAb that was broadly cross-reactive with E. coli, Salmonella, and Shigella endotoxins also proved to be highly effective in the IML assay for capturing LPS molecules from both E. coli and S. typhimurium strains. These results indicate that IML assays can detect smooth-type enterobacterial endotoxins in plasma and suggest that such assays have potential for use in the rapid diagnosis of sepsis and endotoxemia caused by different enterobacterial specie

Safety, Immunogenicity, and Transmissibility of Single-Dose Live Oral Cholera Vaccine Strain CVD l03-HgR in 24- to 59-Month-Old Indonesian Children

Recombinant A-B+ Vibrio cholerae O1 strain CVD 103-HgR is a safe, highly immunogenic, single-dose live oral vaccine in adults in industrialized countries, Safety, excretion, immunogenicity, vaccine transmissibility, and environmental introduction ofCVD 103-HgR were investigated among 24- to 59-month-old children in Jakarta. In 81 households, 1 child was randomly allocated a single dose of vaccine (5 x 109 cfu) and another, placebo. Additionally, 139 unpaired children were randomly allocated vaccine or placebo. During 9 days of follow-up, diarrhea or vomiting did not occur more often among vaccinees than controls. Vaccine was minimally excreted and was isolated from no controls and from 1 (0.6%) of 177 unvaccinated family contacts. A 4-fold or higher rise in serum vibriocidal antibody was observed in 75% of vaccinees (10-fold rise in geometric mean titer over baseline). Of 135 paired placebo recipients or household contacts, 5 had vibriocidal seroconversions. Moore swabs placed in sewers and latrines near 97 households failed to detect vaccine. These observations pave the way for a large-scale field trial of efficac

Safety and Immunogenicity of Different Immunization Regimens of CVD 103-HgR Live Oral Cholera Vaccine in Soldiers and Civilians in Thailand

Attenuated Vibrio cholerae oral vaccineCVD 103-HgR was well tolerated by 324 Thai soldiers and civilians. Most receiveda single 5 × 108 cfu dose, while 40 each receivedone or two 5 × 109 cfu doses. Vibriocidal antibody (the best correlate of immunity) seroconversion was lower in soldiers than civilians (P < .001). Increasing the vaccinedose to 5 × 109 cfu raised the geometric mean titer (P < .001).Asecond 5 × 109 cfu dose one weeklater did not notably increase seroconversions. Likelihood of seroconversionwas inverselycorrelated with baseline vibriocidal titer (P < .001). CVD 103-HgR caused seroconversion in most subjects with baseline titers ⩽1:40, including 100% of civilians after one 5 × 108 cfu dose, 79% of soldiers after one 5 × 109 cfu dose, and 45% of soldiers after one 5 × 108 cfu dose. In persons with elevatedbaseline titers, vibriocidal antibody seroconversion is not a sensitive measure of whether vaccine has boosted intestinal immunity; for such subjects,other measurements must be used. Study regimens in endemic areas should use a single 5 × 109 cfu dos