Jon E. Stek

Efficacy, Safety, and Tolerability of Herpes Zoster Vaccine in Persons Aged 50–59 Years

BACKGROUND Herpes zoster (HZ) adversely affects individuals aged 50-59, but vaccine efficacy has not been assessed in this population. This study was designed to determine the efficacy, safety, and tolerability of zoster vaccine for preventing HZ in persons aged 50-59 years. METHODS This was a randomized, double-blind, placebo-controlled study of 22 439 subjects aged 50-59 years conducted in North America and Europe. Subjects were given 1 dose of licensed zoster vaccine (ZV) (Zostavax; Merck) and followed for occurrence of HZ for ≥1 year (mean, 1.3 years) postvaccination until accrual of ≥96 confirmed HZ cases (as determined by testing lesions swabs for varicella zoster virus DNA by polymerase chain reaction). Subjects were followed for all adverse events (AEs) from day 1 to day 42 postvaccination and for serious AEs (SAEs) through day 182 postvaccination. RESULTS The ZV reduced the incidence of HZ (30 cases in vaccine group, 1.99/1000 person-years vs 99 cases in placebo group, 6.57/1000 person-years). Vaccine efficacy for preventing HZ was 69.8% (95% confidence interval, 54.1-80.6). AEs were reported by 72.8% of subjects in the ZV group and 41.5% in the placebo group, with the difference primarily due to higher rates of injection-site AEs and headache. The proportion of subjects reporting SAEs occurring within 42 days postvaccination (ZV, 0.6%; placebo, 0.5%) and 182 days postvaccination (ZV, 2.1%; placebo, 1.9%) was similar between groups. CONCLUSIONS In subjects aged 50-59 years, the ZV significantly reduced the incidence of HZ and was well tolerated. CLINICAL TRIALS REGISTRATION NCT00534248.

Lack of a Significant Drug Interaction between Raltegravir and Tenofovir

ABSTRACT Raltegravir is a novel human immunodeficiency virus type 1 (HIV-1) integrase inhibitor with potent in vitro activity (95% inhibitory concentration of 31 nM in 50% human serum). This article reports the results of an open-label, sequential, three-period study of healthy subjects. Period 1 involved raltegravir at 400 mg twice daily for 4 days, period 2 involved tenofovir disoproxil fumarate (TDF) at 300 mg once daily for 7 days, and period 3 involved raltegravir at 400 mg twice daily plus TDF at 300 mg once daily for 4 days. Pharmacokinetic profiles were also determined in HIV-1-infected patients dosed with raltegravir monotherapy versus raltegravir in combination with TDF and lamivudine. There was no clinically significant effect of TDF on raltegravir. The raltegravir area under the concentration time curve from 0 to 12 h (AUC0-12) and peak plasma drug concentration (Cmax) were modestly increased in healthy subjects (geometric mean ratios [GMRs], 1.49 and 1.64, respectively). There was no substantial effect of TDF on raltegravir concentration at 12 h postdose (C12) in healthy subjects (GMR [TDF plus raltegravir-raltegravir alone], 1.03; 90% confidence interval [CI], 0.73 to 1.45), while a modest increase (GMR, 1.42; 90% CI, 0.89 to 2.28) was seen in HIV-1-infected patients. Raltegravir had no substantial effect on tenofovir pharmacokinetics: C24, AUC, and Cmax GMRs were 0.87, 0.90, and 0.77, respectively. Coadministration of raltegravir and TDF does not change the pharmacokinetics of either drug to a clinically meaningful degree. Raltegravir and TDF may be coadministered without dose adjustments.

Impact of Acute Rotavirus Gastroenteritis on Pediatric Outpatient Practices in the United States

Objectives: The objectives of this study were to determine the presenting symptoms, healthcare utilization, and lost time from work and day care associated with acute rotavirus gastroenteritis. Methods: During the winter to spring seasons of 2002–2003 or 2003–2004, children <36 months of age presenting with acute gastroenteritis to urban and suburban pediatric outpatient practices affiliated with 5 academic centers across the United States were enrolled in similarly designed studies. The case definition required ≥3 watery or looser-than-normal stools and/or forceful vomiting within a 24-hour period beginning ≤72 hours before presentation. Stool samples were tested for rotavirus antigen by standard commercial assays. Symptom frequencies for laboratory-confirmed rotavirus and nonrotavirus gastroenteritis were compared by Fishers exact test; the number of healthcare contacts and lost days from work or day care were compared with the median 2-sample test. Results: Stool specimens were obtained from 284 of 303 (94%) participants; 115 (40%) of tested specimens were positive for rotavirus (range, 31–50% across the 5 centers). Compared with participants with nonrotavirus gastroenteritis, children with rotavirus gastroenteritis were more likely to have 1) vomiting (83% versus 66%; P = 0.003), 2) combined diarrhea and vomiting (75% versus 50%; P < 0.001), and 3) fever (60% versus 43%; P = 0.010). More time from work was lost by parents/guardians of children with rotavirus than nonrotavirus gastroenteritis (median 2 versus 0 day; P = 0.007). More day care was missed by children with rotavirus than nonrotavirus gastroenteritis (median 3 versus 1 day; P = 0.002). Conclusions: In this multicenter study, rotavirus consistently caused a sizable proportion of cases of acute gastroenteritis seen in pediatric outpatient practices in the United States during the winter and spring. Rotavirus gastroenteritis was more frequently associated with vomiting, combined diarrhea and vomiting, fever and lost time from work and day care than nonrotavirus gastroenteritis.

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 and Immunogenicity of Heat-Treated Zoster Vaccine (ZVHT) in Immunocompromised Adults

BACKGROUND Safety and immunogenicity of heat-treated zoster vaccine (ZVHT) were assessed in immunocompromised adults. METHODS In a randomized, double-blind, placebo-controlled, multicenter study, 4 doses ZVHT or placebo were administered approximately 30 days apart to adults with either solid tumor malignancy (STM); hematologic malignancy (HM); human immunodeficiency virus (HIV) with CD4(+) ≤200; autologous hematopoietic stem-cell transplant (HCT) or allogeneic-HCT recipients. Varicella-zoster virus (VZV) T-cell responses by interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT) and VZV antibody concentrations by glycoprotein enzyme-linked immunosorbent assay (gpELISA) were measured at baseline and approximately 28 days after each dose. RESULTS No safety signals were found in any group. IFN-γ ELISPOT geometric mean fold rises (GMFR) after dose 4 in STM, HM, HIV, and autologous-HCT patients were 3.00 (P < .0001), 2.23 (P = .004), 1.76 (P = .026), and 9.01 (P = NA), respectively. Similarly, antibody GMFR were 2.35 (P < .0001), 1.28 (P = .003), 1.37 (P = .017), and 0.90 (P = NA), respectively. T-cell and antibody responses were poor after 4 doses of ZVHT in allogeneic-HCT patients. CONCLUSION ZVHT was generally safe and immunogenic through 28 days post-dose 4 in adults with STM, HM, and HIV. Autologous-HCT but not allogeneic-HCT patients had a rise in T-cell response; antibody responses were not increased in either HCT population. Study identification. V212-002 Clinical Trials Registration. NCT00535236.

Concomitant use of an oral live pentavalent human-bovine reassortant rotavirus vaccine with licensed parenteral pediatric vaccines in the United States

Background: A live pentavalent rotavirus vaccine (PRV) containing 5 human-bovine (WC3) reassortants expressing human serotypes G1, G2, G3, G4 and P1A[8] was evaluated in a blinded, placebo-controlled study. Possible interactions between PRV and concomitantly administered licensed pediatric vaccines were investigated in a United States-based nested substudy (Concomitant Use Study) of the Rotavirus Efficacy and Safety Trial. Methods: From 2002 to 2003, healthy infants approximately 6 to 12 weeks of age at entry were randomized to receive either 3 oral doses of PRV or placebo at 4- to 10-week intervals. Subjects were also to receive combined Haemophilus influenzae type b and hepatitis B vaccine (2 doses), diphtheria and tetanus toxoids and acellular pertussis vaccine (3 doses), inactivated poliovirus vaccine (2 doses) and pneumococcal conjugate vaccine (3 doses) on the same day; oral poliovirus vaccine was not administered. Immunogenicity was assessed by measuring antibody responses to PRV and antigens contained in the licensed vaccines. Cases of rotavirus gastroenteritis were defined by forceful vomiting and/or ≥3 watery or looser-than-normal stools within a 24-hour period, and detection of rotavirus antigen in the stool. Safety was assessed by reporting of adverse events using diary cards. Results: The Concomitant Use Study enrolled 662 subjects in the PRV group and 696 subjects in the placebo group. For the 17 antigens in the concomitantly administered vaccines, antibody responses were similar in PRV and placebo recipients, except for moderately diminished antibody responses to the pertactin component of pertussis vaccine. Efficacy of PRV against rotavirus gastroenteritis of any severity was 89.5% (95% CI = 26.5–99.8%). PRV was generally well tolerated when given concomitantly with the prespecified vaccines. Conclusions: In this study, antibody responses to the concomitantly administered vaccines were generally similar in PRV and placebo recipients. PRV was efficacious and well tolerated when given concomitantly with pediatric vaccines licensed in the United States.

Safety, tolerability, and immunogenicity after 1 and 2 doses of zoster vaccine in healthy adults ≥60 years of age

BACKGROUND Incidence and severity of herpes zoster (HZ) and postherpetic neuralgia increase with age, associated with age-related decrease in immunity to varicella-zoster virus (VZV). One dose of zoster vaccine (ZV) has demonstrated substantial protection against HZ; this study examined impact of a second dose of ZV. METHODS Randomized, double-blind, multicenter study with 210 subjects ≥60 years old compared immunity and safety profiles after one and two doses of ZV, separated by 6 weeks, vs. placebo. Immunogenicity was evaluated using VZV interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay and VZV glycoprotein enzyme-linked immunosorbent antibody (gpELISA) assay. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card. RESULTS No serious vaccine-related AEs occurred. VZV IFN-γ ELISPOT geometric mean count (GMC) of spot-forming cells per 10(6) peripheral blood mononuclear cells increased in the ZV group from 16.9 prevaccination to 49.5 and 32.8 at 2 and 6 weeks postdose 1, respectively. Two weeks, 6 weeks and 6 months postdose 2, GMC was 44.3, 42.9, and 36.5, respectively. GMC in the placebo group did not change during the study. The peak ELISPOT response occurred ∼2 weeks after each ZV dose. The gpELISA geometric mean titers (GMTs) in the ZV group were higher than in the placebo group at 6 weeks after each dose. Correlation between the IFN-γ ELISPOT and gpELISA assays was poor. CONCLUSIONS ZV was generally well-tolerated and immunogenic in adults ≥60 years old. A second dose of ZV was generally safe, but did not boost VZV-specific immunity beyond levels achieved postdose 1.

Safety and tolerability of zoster vaccine in adults ≥60 years old

Objective To evaluate the general safety of zoster vaccine (ZV) in adults ≥60 years old. Patients/Methods Subjects were enrolled in a 1:1 ratio to receive 1 dose of ZV or placebo. Subjects were followed for serious adverse experiences (SAEs) for 42 days (primary follow-up period) and 182 days (secondary follow-up period) postvaccination. Relative-risks (ZV/placebo) for SAEs during both safety periods were calculated. Study period: 17-Sep‑2007 to 09-Jan-2009. Results Overall, 5,983 subjects received ZV and 5,997 received placebo. Within the primary 42-day follow-up period, 84 ZV subjects and 67 placebo subjects reported SAEs. The estimated risk of SAEs within 42 days was 1.41% for ZV versus 1.12% for placebo, with a relative-risk of 1.26 (95% CI 0.91,1.73); indicating no statistically significant difference between groups, meeting the pre-specified success criterion. During the 182-day follow-up period, 340 ZV subjects and 300 placebo subjects reported SAEs. The estimated risk of SAEs within 182 days was 5.68% for ZV versus 5.01% for placebo, with a relative-risk of 1.13 (95% CI 0.98,1.32), indicating no statistically significant difference between groups. Two subjects in the ZV group reported SAEs deemed by the investigator to be vaccine-related (uveitis and sciatica; onset Day 5 and 4, respectively). One subject in the placebo group reported a SAE deemed by the investigator to be vaccine-related (lumbar radiculopathy; onset Day 51). There were 24 fatal SAEs in the ZV group and 17 in the placebo group (relative risk = 1.41; CI: 0.77, 2.60); 6 and 5, respectively, with SAE onset during the primary 42-day follow-up period. No deaths were deemed vaccine-related. Conclusions ZV and placebo groups had similar safety profiles in terms of SAEs during the primary (Day 1 to 42) and secondary (Day 1 to 182) follow-up periods.

Safety and Immunogenicity of the Merck Adenovirus Serotype 5 (MRKAd5) and MRKAd6 Human Immunodeficiency Virus Type 1 Trigene Vaccines Alone and in Combination in Healthy Adults

ABSTRACT Preexisting immunity to adenovirus serotype 5 (Ad5) diminishes immune responses to vaccines using Ad5 as a vector. Alternate Ad serotypes as vaccine vectors might overcome Ad5-specific neutralizing antibodies and enhance immune responses in populations with a high prevalence of Ad5 immunity. To test this hypothesis, healthy human immunodeficiency virus (HIV)-seronegative adults were enrolled in a blinded, randomized, dose-escalating, placebo-controlled study. In part A, subjects with baseline Ad6 titers of ≤18 received the Merck Ad6 (MRKAd6) HIV type 1 (HIV-1) trigene vaccine at weeks 0, 4, and 26. In part B, subjects stratified by Ad5 titers (≤200 or >200) and Ad6 titers (≤18 or >18) received the MRKAd5-plus-MRKAd6 (MRKAd5+6) HIV-1 trigene vaccine at weeks 0, 4, and 26. Immunogenicity was assessed by an enzyme-linked immunospot (ELISPOT) assay at week 30. No serious adverse events occurred. MRKAd6 trigene vaccine recipients responded more often to Nef than to Gag or Pol. In part A, ELISPOT response rates to ≥2 vaccine antigens were 14%, 63%, and 71% at 109, 1010, and 1011 viral genomes (vg)/dose, respectively. All responders had positive Nef-specific ELISPOT results. In part B, Nef-ELISPOT response rates at 1010 vg/dose of the MRKAd5+6 trigene vaccine were 50% in the low-Ad5/low-Ad6 stratum (n = 8), 78% in the low-Ad5/high-Ad6 stratum (n = 9), 75% in the high-Ad5/low-Ad6 stratum (n = 8), and 44% in the high-Ad5/high-Ad6 stratum (n = 9). The MRKAd6 and MRKAd5+6 trigene vaccines elicited dose-dependent responses predominantly to Nef and were generally well tolerated, indicating that Ad6 should be considered a candidate vector for future vaccines. Although small sample sizes limit the conclusions that can be drawn from this exploratory study, combining two Ad vectors may be a useful vaccine strategy for circumventing isolated immunity to a single Ad serotype.

Varicella-zoster virus-specific antibody responses in 50-59-year-old recipients of zoster vaccine.

Prevaccination and 6-week postvaccination samples from the immunogenicity substudy (n = 2269) of the zoster vaccine (ZV) efficacy trial (N = 22 439) in 50-59-year-old subjects were examined for varicella-zoster virus-specific antibody responses to vaccination. The varicella-zoster virus geometric mean titer (GMT) and geometric mean fold rise were higher in ZV recipients than in placebo recipients (GMT, 660.0 vs 293.1 glycoprotein enzyme-linked immunosorbent assay units/mL [P < .001], respectively; geometric mean fold rise, 2.31 vs 1.00 [P < .025]). In each group there was a strong inverse correlation between postvaccination GMT and risk of subsequent herpes zoster. Although these data provide strong evidence that relates ZV-induced antibody and the risk of herpes zoster, a protective threshold was not determined. Clinical Trials Registration. NCT00534248.