VE303, a Defined Bacterial Consortium, for Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial

Importance

The effect of rationally defined nonpathogenic, nontoxigenic, commensal strains of Clostridia on prevention of Clostridioides difficile infection (CDI) is unknown.

Objective

To determine the efficacy of VE303, a defined bacterial consortium of 8 strains of commensal Clostridia, in adults at high risk for CDI recurrence. The primary objective was to determine the recommended VE303 dosing for a phase 3 trial.

Design, Setting, and Participants

Phase 2, randomized, double-blind, placebo-controlled, dose-ranging study conducted from February 2019 to September 2021 at 27 sites in the US and Canada. The study included 79 participants aged 18 years or older who were diagnosed with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence (defined as aged ≥75 years or ≥65 years with ≥1 risk factors: creatinine clearance <60 mL/min/1.73 m2, proton pump inhibitor use, remote [>6 months earlier] CDI history).

Interventions

Participants were randomly assigned to high-dose VE303 (8.0 × 109 colony-forming units [CFUs]) (n = 30), low-dose VE303 (1.6 × 109 CFUs) (n = 27), or placebo capsules (n = 22) orally once daily for 14 days.

Main Outcomes and Measures

The primary efficacy end point was the proportion of participants with CDI recurrence at 8 weeks using a combined clinical and laboratory definition. The primary efficacy end point was analyzed in 3 prespecified analyses, using successively broader definitions for an on-study CDI recurrence: (1) diarrhea consistent with CDI plus a toxin-positive stool sample; (2) diarrhea consistent with CDI plus a toxin-positive, polymerase chain reaction-positive, or toxigenic culture-positive stool sample; and (3) diarrhea consistent with CDI plus laboratory confirmation or (in the absence of a stool sample) treatment with a CDI-targeted antibiotic.

Results

Baseline characteristics were similar across the high-dose VE303 (n = 29; 1 additional participant excluded from efficacy analysis), low-dose VE303 (n = 27), and placebo (n = 22) groups. The participants' median age was 63.5 years (range, 24-96); 70.5% were female; and 1.3% were Asian, 1.3% Black, 2.6% Hispanic, and 96.2% White. CDI recurrence rates through week 8 (using the efficacy analysis 3 definition) were 13.8% (4/29) for high-dose VE303, 37.0% (10/27) for low-dose VE303, and 45.5% (10/22) for placebo (P = .006, high-dose VE303 vs placebo).

Conclusions and Relevance

Among adults with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence, high-dose VE303 prevented recurrent CDI compared with placebo. A larger, phase 3 study is needed to confirm these findings.

Trial Registration

ClinicalTrials.gov Identifier: NCT03788434.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects on chronic/maintenance corticosteroids

BACKGROUND

This randomized, placebo-controlled study assessed the safety, tolerability, and immunogenicity of live virus zoster vaccine (ZV) in individuals receiving chronic/maintenance systemic corticosteroid therapy (daily dose equivalent of 5-20mg prednisone) for ≥2 weeks prior to vaccination and ≥6 weeks postvaccination.

METHODS

Subjects were followed for adverse experiences (AEs), exposure to varicella or herpes zoster (HZ), or development of varicella/varicella-like or HZ/HZ-like rashes for 42 days postvaccination (primary safety follow-up period) and for serious AEs (SAEs) through Day 182 postvaccination (secondary follow-up period). Varicella-zoster virus (VZV) antibody titers by glycoprotein enzyme-linked immunosorbent assay (gpELISA) were measured at baseline and at Week 6 postvaccination.

RESULTS

The proportions of subjects reporting systemic AEs and SAEs were similar in both groups. A higher percentage of subjects reported injection-site AEs in the ZV group (21.5%) than in the placebo group (12.1%). One SAE of ophthalmic HZ (onset Day 16 postvaccination) was reported in the ZV group and deemed vaccine-related by the study investigator; however, PCR testing confirmed the presence of wild-type (not vaccine strain) VZV. Geometric mean titer (GMT) at 6 weeks postvaccination was higher for ZV recipients than placebo recipients, with estimated geometric mean fold rises (GMFR) of 2.3 (CI: 2.0, 2.7) and 1.1 (CI: 1.0, 1.2) respectfully.

CONCLUSIONS

In adults ≥60 years old on chronic/maintenance corticosteroids, ZV was generally well tolerated and immunogenic. The VZV-specific gpELISA antibody GMT at 6 weeks postvaccination and the GMFR from baseline to 6 weeks postvaccination were higher in the ZV group than in the placebo group.

Safety and Immunogenicity of Two Formulations of a Hexavalent Diphtheria-Tetanus-Acellular Pertussis-Inactivated Poliovirus-Haemophilus influenzaeb Conjugate-Hepatitis B Vaccine in 15 to 18 Month-Old Children

Combination vaccines decrease the number of injections and improve parental satisfaction and vaccination schedule compliance. In a phase 1, randomized, partially-blinded, single-dose booster study, we evaluated two formulations of an investigational liquid hexavalent vaccine containing diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate and hepatitis B surface antigen (DTaP-IPV-Hib-HBV) in 60 healthy toddlers, 15 to 18 months of age, who had been primed with three doses of a licensed pentavalent diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate (DTaP-IPV//PRP-T) vaccine. The DTaP-IPV//PRP-T vaccine was used as a control in 30 subjects. The investigational formulations, which contained the same DTaP-IPV components, differed only in Hib (content and conjugate) and HBV (content) (PRP-T/HBV10 = 12 mug Hib tetanus toxoid conjugate with 10 microg HBsAg; PRP-OMPC/HBV15 = 6 microg Hib Neisseria meningitidis outer membrane protein complex with 15 microg HBsAg). Injection-site pain, redness and swelling were reported by 46.7%, 46.7%, and 20.0% of the licensed vaccine recipients, 43.3%, 43.3%, and 26.7% of PRP-T/HBV10 recipients and 70.0%, 46.7%, and 46.7% of PRP-OMPC/HBV15 recipients, respectively. Fever > or = 37.8 degrees C and irritability were reported by 0% and 16.7% of licensed vaccine recipients, 10.3% and 23.3% of PRP-T/HBV10 recipients and 30.0% and 16.7% of PRP-OMPC/HBV15 recipients, respectively. There were no apparent differences between the groups in the proportion of participants achieving predefined, threshold or seroprotective immune responses. Geometric mean antibody levels for all antigens were similar except for anti-PRP levels, which were 19.0 microg/mL in recipients of the licensed vaccine, 40.8 microg/mL in PRP-T/HBV10 recipients and 9.4 microg/mL in PRP-OMPC/HBV15 recipients. We conclude that the hexavalent formulations appear generally well tolerated and immunogenic as a booster dose in these toddlers.

Safety of zoster vaccine in elderly adults following documented herpes zoster

BACKGROUND

After completion of the Shingles Prevention Study (SPS; Department of Veterans Affairs Cooperative Studies Program Number 403), SPS participants who had initially received placebo were offered investigational zoster vaccine without charge. This provided an opportunity to determine the relative safety of zoster vaccine in older adults following documented herpes zoster (HZ).

METHODS

A total of 13 681 SPS placebo recipients who elected to receive zoster vaccine were followed for serious adverse events (SAE) for 28 days after vaccination. In contrast to the SPS, a prior episode of HZ was not a contraindication to receiving zoster vaccine. The SPS placebo recipients who received zoster vaccine included 420 who had developed documented HZ during the SPS.

RESULTS

The mean interval between the onset of HZ and the receipt of zoster vaccine in the 420 recipients with prior HZ was 3.61 years (median interval, 3.77 years [range, 3-85 months]); the interval was <5 years for approximately 80% of recipients. The proportion of vaccinated SPS placebo recipients with prior HZ who developed ≥ 1 SAE (0.95%) was not significantly different from that of vaccinated SPS placebo recipients with no prior history of HZ (0.66%), and the distribution of SAEs in the 2 groups was comparable.

CONCLUSIONS

These results demonstrate that the general safety of zoster vaccine in older persons is not altered by a recent history of documented HZ, supporting the safety aspect of the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommendation to administer zoster vaccine to all persons ≥ 60 years of age with no contraindications, regardless of a prior history of HZ.

Concomitant administration of zoster and pneumococcal vaccines in adults ≥60 years old

This study evaluated safety & immunogenicity of ZOSTAVAX® (zoster vaccine: ZV) administered concomitantly versus nonconcomitantly with PNEUMOVAX® 23 (pneumococcal vaccine: PPV23). This randomized, double-blind, placebo-controlled study enrolled 473 subjects ≥60 years old in 1:1 ratio to receive ZV & PPV23 concomitantly (Day 1) or nonconcomitantly (PPV23 Day 1, ZV Week 4). Blood samples obtained for pneumococcal polysaccharide (PnPs) antibody (Ab) testing by enzyme-linked immunosorbent assay (ELISA) and varicella-zoster virus (VZV) Ab testing by glycoprotein ELISA. Subjects followed for adverse experiences (AEs) for 28 days postvaccination. Mean baseline VZV geometric mean titers (GMT) in nonconcomitant group were lower than concomitant group. Four weeks postvaccination with ZV, VZV Ab response in concomitant group was not similar to nonconcomitant group; estimated VZV GMT ratio [concomitant/nonconcomitant] was 0.70 (95% CI, 0.61-0.80). VZV Ab response was acceptable in concomitant group; estimated geometric mean foldrise (GMFR) from baseline was 1.9 (95% CI, 1.7-2.1). PnPs serotype-specific Ab responses were similar in both groups. All 6 reported serious AEs were deemed not related to study vaccine. Postvaccination of ZV, incidence of injection-site AEs was similar in both groups; clinical AEs were numerically but not significantly higher in nonconcomitant group. In summary, VZV GMT Ab response induced by ZV administered concomitantly with PPV23 was inferior to that induced nonconcomitantly. These results indicate that, to avoid a potential decrease in ZV immunogenicity, ZV & PPV23 should not be given concomitantly. Concomitant administration did not affect response to PPV23 serotypes tested. When administered concomitantly, ZV & PPV23 vaccines were generally well tolerated.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects with a history of herpes zoster

BACKGROUND

Prior clinical studies of zoster vaccine enrolled subjects without a history of herpes zoster (HZ), so there are limited data on safety and immunogenicity in vaccinees with a prior history of HZ. This study was conducted to evaluate the safety and immunogenicity of zoster vaccine recipients who had a prior episode of HZ.

METHODS

A total of 101 subjects > or = 50 years of age with a prior history of HZ were enrolled. They were stratified by number of years since their HZ (5 to 9 years and > or = 10 years, in an approximate 2:1 ratio), and randomized 1:1 to one of two vaccination groups. On day 1, Group I was administered zoster vaccine and Group II received placebo. At week 4, Group I received placebo and Group II received zoster vaccine. Subjects were followed for adverse experiences (AEs), exposure to varicella or HZ, and development of any varicella/varicella-like or HZ/HZ-like rashes, for 28 days after each injection. Blood samples were obtained prior to study injection on day 1 and week 4, and at week 8. Serum was assessed for varicella-zoster virus (VZV) antibody concentration by glycoprotein enzyme-linked immunosorbent assay.

RESULTS

No serious AEs were reported within the 28-day safety follow-up period following any vaccination. Although a higher percentage of subjects reported injection-site AEs after receiving zoster vaccine than did placebo recipients, the proportion of subjects reporting systemic clinical AEs was similar in both groups. Zoster vaccine induced a VZV antibody response at 4 weeks post-vaccination. The estimated geometric mean titer (GMT) ratio (vaccine/placebo) was 2.07 (95% CI: 1.48, 2.88). The geometric mean fold-rise (GMFR) from prevaccination to week 4 post-vaccination was 2.1 in zoster vaccine recipients, versus 1.0 in placebo recipients.

CONCLUSIONS

In HZ history-positive adults > or = 50 years of age, zoster vaccine: (1) was well tolerated; and (2) significantly boosted the level of VZV antibody from baseline to 4 weeks post-vaccination as measured by GMT and GMFR. These data support the Advisory Committee on Immunization Practices' recommendation for routine zoster vaccination for all immunocompetent persons >/=60 years of age irrespective of HZ history.

Influence of age and nature of primary infection on varicella-zoster virus-specific cell-mediated immune responses

BACKGROUND

Varicella-zoster virus (VZV)-specific cell-mediated immunity is important for protection against VZV disease. We studied the relationship between VZV cell-mediated immunity and age after varicella or VZV vaccination in healthy and human immunodeficiency virus (HIV)-infected individuals.

METHODS

VZV responder cell frequency (RCF) determinations from 752 healthy and 200 HIV-infected subjects were used to identify group-specific regression curves on age.

RESULTS

In healthy individuals with past varicella, VZV RCF peaked at 34 years of age. Similarly, VZV-RCF after varicella vaccine increased with age in subjects aged <1 to 43 years. In subjects aged 61-90 years, VZV RCF after zoster vaccine decreased with age. HIV-infected children had lower VZV RCF estimates than HIV-infected adults. In both groups, VZV RCF results were low and constant over age. Varicella vaccination of HIV-infected children with CD4 levels 20% generated VZV RCF values higher than wild-type infection and comparable to vaccine-induced responses of healthy children.

CONCLUSIONS

In immunocompetent individuals with prior varicella, VZV RCF peaked in early adulthood. Administration of varicella vaccine to HIV-infected or uninfected individuals aged >5 years generated VZV RCF values similar to those of immunocompetent individuals with immunity induced by wild-type infection. A zoster vaccine increased the VZV RCF of elderly adults aged <75 years to values higher than peak values induced by wild-type infection.

A double-blind, randomized, controlled, multicenter safety and immunogenicity study of a refrigerator-stable formulation of Zostavax

The vaccine Zostavax has been shown to prevent herpes zoster (HZ) and postherpetic neuralgia and is recommended for individuals > or =60 years of age. This study compared the safety and the immunogenicity of a refrigerator-stable formulation (Zostavax refrigerated) with those of the current formulation (Zostavax frozen) in subjects > or =50 years of age. Subjects with a negative history for HZ were randomized 1:1 to receive one dose of either formulation. Enrollment was stratified 1:2 by age (50 to 59 years and > or =60 years). Safety was evaluated for 28 days postvaccination. Varicella-zoster virus (VZV) antibody responses were measured by a glycoprotein enzyme-linked immunosorbent assay (gpELISA). The primary endpoints were the VZV antibody geometric mean titer (GMT; day 28), the VZV antibody geometric mean rise (GMR; days 1 to 28), and the incidence of vaccine-related serious adverse experiences (AEs) over 28 days. The refrigerated (n = 182) and frozen (n = 185) formulations induced similar GMTs (727.4 and 834.4 gpELISA units/ml, respectively); the estimated GMT ratio (refrigerated formulation/frozen formulation) was 0.87 (95% confidence interval, 0.71 to 1.07). The GMRs were 2.6- and 2.9-fold, respectively. No vaccine-related serious AEs were reported in either group, and the safety profiles of the formulations were generally similar. The frequencies of injection-site AEs during follow-up were 35.6% and 46.4% in the refrigerated and the frozen formulation groups, respectively, and were generally mild. The frequencies of systemic AEs were similar in the two groups, and those of vaccine-related AEs were approximately 6% in both groups. The refrigerator-stable formulation of Zostavax has an acceptable safety profile and is as immunogenic as the frozen formulation; thus, the vaccine may be used in clinical settings where freezer availability is limited.

Safety and immunogenicity profile of the concomitant administration of ZOSTAVAX and inactivated influenza vaccine in adults aged 50 and older

OBJECTIVES

To evaluate the safety and immunogenicity of ZOSTAVAX administered concomitantly with inactivated influenza vaccine or sequentially in adults aged 50 and older.

DESIGN

Randomized, blinded, placebo-controlled study.

SETTING

Thirteen U.S. and seven European study sites.

PARTICIPANTS

Three hundred eighty-two concomitantly, 380 sequentially vaccinated subjects.

INTERVENTION

The concomitant vaccination group received influenza vaccine and ZOSTAVAX at separate injection sites on Day 1 and placebo at Week 4. The nonconcomitant vaccination group received influenza vaccine and placebo at separate injection sites on Day 1 and ZOSTAVAX at Week 4.

MEASUREMENTS

Primary safety endpoints: vaccine-related serious adverse experiences (AEs) within 28 days postvaccination (PV); and diary card-prompted local and systemic AEs. Primary immunogenicity endpoints: geometric mean titer (GMT) and geometric mean fold rise (GMFR) from baseline of varicella-zoster virus (VZV) antibody (Ab) at 4 weeks PV according to glycoprotein enzyme-linked immunosorbent assay (gpELISA) and GMT of influenza Ab for the three vaccine strains (2005-2006 influenza season) at 4 weeks PV according to hemagglutination inhibition assay. Secondary immunogenicity endpoint: influenza seroconversion rates (SCRs).

RESULTS

No serious AEs related to ZOSTAVAX were observed during the study. VZV Ab GMTs 4 weeks PV for the concomitant and sequential groups were 554 and 597 gpELISA U/mL, respectively. The estimated VZV Ab GMT ratio was 0.9 (95% confidence interval (CI)=0.8-1.0), indicating noninferior (P<.001 for the null hypothesis of GMT ratio <0.67) responses. Estimated VZV Ab GMFR from baseline in the concomitant group was 2.1 (95% CI=2.0-2.3), indicating acceptable fold rise. Estimated GMT ratios (concomitant/sequential) for influenza strains A(H1N1), A(H3N2), and B were 0.9 (95% CI=0.8-1.1), 1.1 (95% CI=0.9-1.3), and 0.9 (95% CI=0.8-1.1), respectively, and SCRs were comparable across both groups, with more than 85% achieving titers of 1:40 or greater, meeting regulatory criteria.

CONCLUSION

ZOSTAVAX and influenza vaccine given concomitantly are generally well tolerated in adults aged 50 and older. Ab responses were similar whether ZOSTAVAX and influenza vaccine were given concomitantly or sequentially.

Immunogenicity of Oka/Merck varicella vaccine in children vaccinated at 12-14 months of age versus 15-23 months of age

OBJECTIVE

Recent reports suggest that breakthrough varicella may be more common in children when the Oka/Merck varicella vaccine is given at 12-14 months of age than when it is given at older ages. An analysis of 5 postlicensure clinical trials with this vaccine was conducted to evaluate immune response relative to the age of the vaccine recipient.

METHODS

In 5 clinical trials, 3771 children, 12 through 23 months of age with no history of varicella, received an injection of varicella vaccine. Varicella-zoster virus (VZV) antibody was measured 6 weeks postvaccination by glycoprotein enzyme-linked immunosorbent assay (gpELISA), an assay that correlates with neutralizing antibody. Endpoints evaluated were the response rate (percent of subjects with VZV antibody > or =5 gpELISA units/mL, a titer shown to correlate with protection) and geometric mean titer (GMT) of VZV antibody. Each endpoint was compared across 3 age groups (12-14, 15-17, and 18-23 months of age). Response rates by initial VZV serostatus were evaluated for children vaccinated at 12-14 months of age to assess whether maternal antibody had an impact on the immune response.

RESULTS

The response rates were similar among 12-14, 15-17, and 18-23 month olds (93.8, 90.8, and 93.1%, respectively); GMTs were significantly higher among the 12-14 month olds (15.1, 13.5, and 13.7 gpELISA units/mL, respectively). Among children 12-14 months of age, response rates and GMTs were similar regardless of their prevaccination VZV serostatus.

CONCLUSIONS

Oka/Merck varicella vaccine is highly immunogenic when given to children 12-14 months of age. The immunogenicity profile is similar to that of children 15-17 and 18-23 months of age. The presence of low titers of VZV antibody before vaccination did not influence vaccine response in 12-14 month olds. These results support current recommendations for universal varicella vaccination beginning at 12 months of age.

Safety and immunogenicity of a zoster vaccine in varicella-zoster virus seronegative and low-seropositive healthy adults

OBJECTIVE

To evaluate immunogenicity and tolerability of a live attenuated zoster vaccine in varicella-zoster virus (VZV) seronegative or low-seropositive adults > or = 30 years of age.

STUDY DESIGN

Double-blind, placebo-controlled, randomized, multicenter study. Subjects were enrolled in two stages by prescreened serostatus. Subjects with a low VZV antibody titer (< or = 5 gpELISA units/mL) were enrolled in Stage 1. Subjects with undetecable VZV antibodies and no safety issues identified during Stage 1 were enrolled in Stage 2. All enrolled subjects were randomized 4:1 to receive one dose (approximately 50,000 PFU) of zoster vaccine or placebo and were followed for safety for 42 days postvaccination. Primary objectives/hypotheses: (1) no vaccine-related serious adverse experiences (AE); (2) < or = 1 laboratory-confirmed varicella-like rash with > 50 lesions within 42 days postvaccination.

SECONDARY OBJECTIVE

summarize the VZV antibody response postvaccination.

RESULTS

Twenty-one subjects (age 27 to 69 years; median 34) enrolled (1148 prescreened); 18 (including 4 seronegative subjects) received vaccine and 3 (including 1 seronegative subject) received placebo. Twenty subjects completed the study; one subject withdrew for reasons unrelated to safety. No serious vaccine-related AE or laboratory-confirmed varicella-like rashes with > 50 lesions were reported. In the zoster vaccine group, all 4 of the initially seronegative subjects (age 32 to 36 years; median 33.5) seroconverted and 6 of the 13 (46.2%) initially seropositive subjects had a > or = 4-fold rise in VZV-specific antibody titer at 6 weeks postvaccination.

CONCLUSIONS

The zoster vaccine appears to be immunogenic and generally well tolerated in healthy adults > or = 30 years of age, regardless of initial VZV antibody serostatus.

Safety, tolerability, and immunogenicity of a two-dose regimen of high-titer varicella vaccine in subjects ≥13 years of age

A new manufacturing process, known as process upgrade varicella vaccine (PUVV) was developed for a refrigerated formulation of varicella vaccine and for an investigational zoster vaccine. Safety and tolerability of a two-dose regimen of high-titered (approximately 50,000 PFU) PUVV were compared to a lower-titer formulation (approximately 5400 PFU) of VARIVAX; in 1366 healthy subjects > or =13 years old. Only one vaccine-related clinical serious adverse experience (pruritus; no hospitalization) was reported, in the VARIVAX group. Injection-site adverse experiences following any dose were higher in the PUVV group, 70.0%, than in the VARIVAX group, 56.2%, but generally were mild. Immunogenicity were similar in both groups in seronegative subjects. PUVV was generally well tolerated, and elicited an immune response similar to that induced by the marketed formulation of VARIVAX.

A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults

BACKGROUND

The incidence and severity of herpes zoster and postherpetic neuralgia increase with age in association with a progressive decline in cell-mediated immunity to varicella-zoster virus (VZV). We tested the hypothesis that vaccination against VZV would decrease the incidence, severity, or both of herpes zoster and postherpetic neuralgia among older adults.

METHODS

We enrolled 38,546 adults 60 years of age or older in a randomized, double-blind, placebo-controlled trial of an investigational live attenuated Oka/Merck VZV vaccine ("zoster vaccine"). Herpes zoster was diagnosed according to clinical and laboratory criteria. The pain and discomfort associated with herpes zoster were measured repeatedly for six months. The primary end point was the burden of illness due to herpes zoster, a measure affected by the incidence, severity, and duration of the associated pain and discomfort. The secondary end point was the incidence of postherpetic neuralgia.

RESULTS

More than 95 percent of the subjects continued in the study to its completion, with a median of 3.12 years of surveillance for herpes zoster. A total of 957 confirmed cases of herpes zoster (315 among vaccine recipients and 642 among placebo recipients) and 107 cases of postherpetic neuralgia (27 among vaccine recipients and 80 among placebo recipients) were included in the efficacy analysis. The use of the zoster vaccine reduced the burden of illness due to herpes zoster by 61.1 percent (P<0.001), reduced the incidence of postherpetic neuralgia by 66.5 percent (P<0.001), and reduced the incidence of herpes zoster by 51.3 percent (P<0.001). Reactions at the injection site were more frequent among vaccine recipients but were generally mild.

CONCLUSIONS

The zoster vaccine markedly reduced morbidity from herpes zoster and postherpetic neuralgia among older adults.

Decline in varicella-zoster virus (VZV)-specific cell-mediated immunity with increasing age and boosting with a high-dose VZV vaccine

The safety and immunogenecity of a booster dose of live attenuated varicella-zoster virus (VZV) vaccine was evaluated in 196 healthy subjects, >or=60 years old, who had already received a VZV vaccine >5 years before. This repeat booster dose was well tolerated. Cell-mediated immunity (CMI) to VZV was measured by an interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot-forming cell (ELISPOT) assay and a limiting dilution responder cell frequency (RCF) assay. Prevaccination responses decreased as a function of increasing age but were detectable in all subjects by use of the IFN-gamma ELISPOT assay. In most subjects, VZV-specific CMI was increased at 6 weeks postvaccination. The magnitude of the vaccine-induced IFN-gamma ELISPOT response was inversely related to prevaccination values. Although there was a significant correlation between the IFN-gamma ELISPOT and RCF assays, the ELISPOT assay had greater sensitivity and a wider dynamic range. A live attenuated VZV vaccine is safe and immunogenic in an elderly population, and the vaccine-induced immunity may be monitored by the IFN-gamma ELISPOT assay.

Amphotericin B lipid complex for invasive fungal infections: analysis of safety and efficacy in 556 cases

The safety and antifungal efficacy of amphotericin B lipid complex (ABLC) were evaluated in 556 cases of invasive fungal infection treated through an open-label, single-patient, emergency-use study of patients who were refractory to or intolerant of conventional antifungal therapy. All 556 treatment episodes were evaluable for safety. During the course of ABLC therapy, serum creatinine levels significantly decreased from baseline (P < .02). Among 162 patients with serum creatinine values > or = 2.5 mg/dL at the start of ABLC therapy (baseline), the mean serum creatinine value decreased significantly from the first week through the sixth week (P < or = .0003). Among the 291 mycologically confirmed cases evaluable for therapeutic response, there was a complete or partial response to ABLC in 167 (57%), including 42% (55) of 130 cases of aspergillosis, 67% (28) of 42 cases of disseminated candidiasis, 71% (17) of 24 cases of zygomycosis, and 82% (9) of 11 cases of fusariosis. Response rates varied according to the pattern of invasive fungal infection, underlying condition, and reason for enrollment (intolerance versus progressive infection). These findings support the use of ABLC in the treatment of invasive fungal infections in patients who are intolerant of or refractory to conventional antifungal therapy.

Fluconazole prophylaxis of fungal infections in patients with acute leukemia. Results of a randomized placebo-controlled, double-blind, multicenter trial

OBJECTIVE

To evaluate the efficacy and safety of fluconazole for prevention of fungal infections.

DESIGN

A randomized, placebo-controlled, double-blind, multicenter trial.

PATIENTS

Adults (257) undergoing chemotherapy for acute leukemia.

INTERVENTION

Patients were randomly assigned to receive either fluconazole (400 mg orally once daily or 200 mg intravenously every 12 hours) or placebo. The study drug was started at initiation of chemotherapy and continued until recovery of neutrophil count, development of proven or suspected invasive fungal infection, or the occurrence of a drug-related toxicity.

MEASUREMENTS

Fungal colonization, proven superficial or invasive fungal infection, empiric antifungal therapy with amphotericin B, drug-related side effects, and mortality.

MAIN RESULTS

Fluconazole decreased fungal colonization (83 of 122 [68%] placebo patients compared with 34 of 119 [29%] fluconazole patients colonized at end of prophylaxis, P < 0.001) and proven fungal infections (27 of 132 [21%] placebo patients compared with 11 of 123 [9%] fluconazole patients infected, P = 0.02). Superficial fungal infections occurred in 20 of 132 (15%) placebo patients but in only 7 of 123 (6%) fluconazole patients (P = 0.01), whereas invasive fungal infections developed in 10 of 132 (8%) placebo patients and in 5 of 123 (4%) fluconazole patients (P = 0.3). Fluconazole was especially effective in eliminating colonization and infection by Candida species other than Candida krusei (66 of 122 [64%] placebo patients colonized at end of prophylaxis compared with 11 of 119 [9%] fluconazole patients, P < 0.001; 22 of 132 [17%] placebo patients infected compared with 7 of 123 [6%] fluconazole patients, P = 0.005). Aspergillus infections were infrequent in both fluconazole (3 cases) and placebo groups (3 cases). The use of amphotericin B, the incidence of drug-related side effects, and overall mortality were similar in both study groups.

CONCLUSION

Prophylactic fluconazole prevents colonization and superficial infections by Candida species other than Candida krusei in patients undergoing chemotherapy for acute leukemia and is well tolerated. Fluconazole could not be clearly shown to be effective for preventing invasive fungal infections, reducing the use of amphotericin B, or decreasing the number of deaths.

Infectious complications of bone marrow transplantation

Patients undergoing bone marrow transplantation face increased risk of infection because of underlying diseases and transplant-associated treatments. Optimal prophylactic strategies and prompt recognition and treatment of infection are crucial.