Stan L Block

University of Louisville, Louisville, Kentucky, United States

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Publications (89)209.73 Total impact

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    ABSTRACT: BACKGROUND: We present a long-term safety, immunogenicity, and effectiveness study of a quadrivalent human papillomavirus (HPV4) vaccine. METHODS: Sexually naive boys and girls aged 9 to 15 years (N = 1781) were assigned (2:1) to receive HPV4 vaccine or saline placebo at day 1 and months 2 and 6. At month 30, the placebo group (n = 482) received HPV4 vaccine following the same regimen and both cohorts were followed through month 96. Subjects >= 16 years were eligible for effectiveness evaluations. The primary objective was to evaluate the long-term anti-HPV6/11/16/18 serological levels. The secondary objective was to estimate vaccine effectiveness against HPV6/11/16/18-related persistent infection or disease. RESULTS: For each of the HPV4 vaccine types, vaccination-induced anti-HPV response persisted through month 96. Among 429 subjects who received HPV4 vaccine at a mean age of 12, none developed HPV6/11/16/18-related disease or persistent infection of >= 12 months' duration. Acquisition of new sexual partners (among those >= 16 years) was similar to 1 per year. Subjects receiving HPV4 vaccine at month 30 (mean age 15 years) had a similar baseline rate of seropositivity to >= 1 of the 4 HPV types to those vaccinated at day 1 (mean age 12 years; 1.9% [9 of 474] vs 1.7% [20 of 1157]); however, 4 of the 9 subjects vaccinated at the later age were seropositive to 3 vaccine types, indicating previous HPV exposure. No new significant serious adverse events were observed for 8 years postvaccination in both genders. CONCLUSIONS: When administered to adolescents, the HPV4 vaccine demonstrated durability in clinically effective protection and sustained antibody titers over 8 years.
    Pediatrics 08/2014; 134(3). DOI:10.1542/peds.2013-4144 · 5.30 Impact Factor
  • Stan L Block
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    ABSTRACT: Petechiae and purpura are among the most alarming findings a pediatrician will commonly observe in the office. Severity of illness can range from a temper tantrum, to common viral infections, to the most deadly infections and diseases. To avoid many of the pitfalls in diagnosis, practitioners will need to be thorough in history taking, assessing fever and immunization status, and physical examination. In addition, a few simple laboratory tests will usually be needed and possibly a manual differential. [Pediatr Ann. 2014;43(8):297-303.].
    Pediatric Annals 08/2014; 43(8):297-303. DOI:10.3928/00904481-20140723-03 · 0.29 Impact Factor
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    ABSTRACT: To ensure adequate protection from seasonal influenza in the US, the Advisory Committee on Immunization Practices recommends vaccination of all persons aged 6 months or older, with rare exceptions. It also advises starting vaccination as soon as available and continuing throughout the influenza season. This study examined US seasonal vaccination trends during five consecutive influenza seasons in privately-insured children and adults.
    Vaccine 07/2014; 32(48). DOI:10.1016/j.vaccine.2014.07.009 · 3.49 Impact Factor
  • Stan L Block
    Pediatric Annals 07/2014; 43(7):256-261. DOI:10.3928/00904481-20140619-04 · 0.29 Impact Factor
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    ABSTRACT: Background: In 2008, the US Advisory Committee on Immunization Practices (ACIP) recommended universal pediatric influenza vaccination for children ≥ 6 months of age. CDC monitors overall influenza vaccination coverage based on systematic surveys, but little is known about trends in pediatric influenza vaccination by private payers. Methods: To describe seasonal influenza vaccination trends among commercially insured children(≤ 18 y.o.) in the U.S., we conducted a retrospective observational cohort study using administrative claims data from a large national insurer. Trends were examined based on current procedural terminology and generic product identifier codes for seasonal influenza vaccines during 2007-08 through 2011-12 seasons. Denominators were the number of children enrolled in the plan for 24 months: 12 months prior and 12 months after 1 July. Office visits were calculated 12 months prior to 1 July. Results: The denominators fluctuated by season and ranged between n=1,277,502 and n=1,363,087. Children <24 months had the highest likelihood to be vaccinated against influenza (47%-55%), and this likelihood decreased with older age (Figure 1). Geographically, children in the Northeast had the highest and children in the West had the lowest likelihood to be vaccinated. However, the differences by region were small (6-8 percentage points), Figure 2. Children with frequent office visits had higher likelihood of seasonal vaccination than those with few office visits (Figure 3). However, the likelihood of vaccination in those with ≥ 6 office visits was still low: 25%-35%. Only 2.4%-5.3% of children with no office visit were vaccinated against influenza. Conclusion: Younger children had a higher likelihood of influenza vaccination than older children. Rates of pediatric vaccination against seasonal influenza remain relatively low. Alternative venues for delivering seasonal influenza vaccines to children should be considered. Figure 1. Percentage vaccinated children by age. Figure 2. Percentage of vaccinated children by region. Figure 3. Percentage of vaccinated children, by the number of office visits the year prior to vaccination season. Evgeniya Antonova, MS, PhD1, David Kern, MS2, Stan Block, MD3,4, Herve Caspard, MD, ScD5, Ozgur Tunceli, PhD2 and Christopher Ambrose, MD5, (1)Medimmune, LLC, Gaithersburg, MD, (2)Health Core, Inc, Wilmington, DE, (3)University of Louisville, Louisville, KY, (4)University of Kentucky, Lexington, KY, (5)MedImmune, LLC, Gaithersburg, MD Disclosures: E. Antonova, MedImmune, LLC: Employee, Salary D. Kern, None S. Block, None H. Caspard, MedImmune: Employee, Salary O. Tunceli, None C. Ambrose, MedImmune: Employee, Salary
    IDWeek 2013 Meeting of the Infectious Diseases Society of America; 10/2013
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    ABSTRACT: BACKGROUND:: Acute otitis media (AOM) is a frequent complication of influenza in children, and influenza vaccination helps protect against influenza-associated AOM. A live attenuated influenza vaccine (LAIV) approved for eligible children aged ≥2 years for the prevention of influenza also effectively reduces influenza-associated AOM. However, the annual effectiveness of LAIV against all-cause AOM is unknown. METHODS:: AOM rates in children 6-83 months of age from 6 randomized, placebo-controlled trials and 2 randomized, inactivated influenza vaccine (IIV)-controlled trials were pooled and analyzed. To enable comparison with studies of AOM prevention by pneumococcal conjugate vaccines (PCV), 12-month effectiveness was calculated assuming that LAIV had no effect outside of influenza seasons. RESULTS:: During influenza seasons, LAIV efficacy compared with placebo against all-cause AOM in children 6-71 months of age (N=9497) was 12.4% (95% CI: 2.0%, 21.6%) in year 1. In year 2, the efficacy in children aged 18-83 months (N=4142) was 6.2% (95% CI: -12.4%, 21.7%). Compared with IIV, the efficacy of LAIV in children 6-71 months (N=9901) against febrile all-cause AOM was 9.7% (95% CI: -2.1%, 20.1%). The estimated 12-month effectiveness of LAIV compared with placebo against all-cause AOM was 7.5% (95% CI: -2.4%, 16.2%). CONCLUSIONS:: LAIV reduced the incidence of all-cause AOM compared with placebo in children. The estimated 12-month effectiveness of LAIV was comparable with PCV7. The effects of the vaccines will overlap somewhat; however, because PCVs only prevent a fraction of all pneumococcal AOM and influenza-associated AOM can be caused by other pathogens, LAIV could further reduce the incidence of AOM in children.
    The Pediatric Infectious Disease Journal 12/2012; 32(6). DOI:10.1097/INF.0b013e3182840fe7 · 3.14 Impact Factor
  • Stan L Block
    Pediatric Annals 12/2012; 41(12):497-501. DOI:10.3928/00904481-20121126-05 · 0.29 Impact Factor
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    ABSTRACT: Influenza B is responsible for significant morbidity in children and adults worldwide. For more than 25 years, two antigenically distinct lineages of influenza B viruses, B/Yamagata and B/Victoria, have cocirculated globally. Current influenza vaccine formulations are trivalent and contain two influenza subtype A strains (A/H1N1 and A/H3N2) but only one B strain. In a half of recent influenza seasons, the predominant circulating influenza B lineage was different from that contained in trivalent influenza vaccines. A quadrivalent live attenuated influenza vaccine (Q/LAIV) that contains two B strains, one from each lineage, has been developed to help provide broad protection against influenza B. Q/LAIV was recently approved for use in the USA in eligible individuals 2-49 years of age. This review summarizes clinical trial data in support of Q/LAIV.
    Expert Review of Vaccines 11/2012; DOI:10.1586/erv.12.108 · 4.22 Impact Factor
  • Stan L Block
    Pediatric Annals 11/2012; 41(11):452-5. DOI:10.3928/00904481-20121018-05 · 0.29 Impact Factor
  • Stan L Block
    Pediatric Annals 10/2012; 41(10):400-3. DOI:10.3928/00904481-20120924-05 · 0.29 Impact Factor
  • Steven Black, Stan L Block
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    ABSTRACT: Adolescents constitute a high-risk group for invasive meningococcal disease. MenACWY-CRM (Menveo, Novartis Vaccines, Cambridge, MA) is a quadrivalent meningococcal conjugate vaccine indicated to prevent invasive meningococcal disease caused by Neisseria meningitidis serogroups A, C, W-135, and Y. It has been approved for use in persons age 2-55 years. The tolerability and immunogenicity of MenACWY-CRM in adolescents have been ascertained in phase 2 and 3 trials against MPSV4 (Menomune, sanofi pasteur, Swiftwater, PA), an unconjugated quadrivalent meningococcal vaccine, and MenACWY-D (Menactra, sanofi pasteur), another conjugated quadrivalent meningococcal vaccine. Clinical trials also have demonstrated that MenACWY-CRM is well tolerated and immunogenic when administered to adolescents concomitantly with the combined tetanus, diphtheria, and acellular pertussis vaccine (Boostrix, GlaxoSmithKline Biologicals, Rixensart, Belgium) and the quadrivalent human papillomavirus vaccine (Gardasil, Merck & Co., Inc., Whitehouse Station, NJ).
    Journal of Adolescent Health 09/2012; DOI:10.1016/j.jadohealth.2012.07.017 · 2.75 Impact Factor
  • Stan L Block
    Pediatric Annals 09/2012; 41(9):356-9. DOI:10.3928/00904481-20120827-05 · 0.29 Impact Factor
  • Stan L Block
    Pediatric Annals 07/2012; 41(7):270-4. DOI:10.3928/00904481-20120625-04 · 0.29 Impact Factor
  • Stan L Block
    Pediatric Annals 06/2012; 41(6):225-8. DOI:10.3928/00904481-20120524-04 · 0.29 Impact Factor
  • Stan L Block
    Pediatric Annals 05/2012; 41(5):182-4. DOI:10.3928/00904481-20120426-04 · 0.29 Impact Factor
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    ABSTRACT: The successful vaccination of children 6 to 36 months of age against 2009 A/H1N1 influenza was essential to help reduce the burden of pandemic disease in both the pediatric and adult populations. We compared the immunogenicity and safety of 4 alternative monovalent vaccine formulations to identify which provided optimal levels of seroprotection according to the US and European Union (EU) licensure criteria. A total of 654 healthy subjects (6 to <36 months old) were given 2 vaccine doses 3 weeks apart. Participants were assigned to 1 of the 4 immunization groups, receiving MF59-adjuvanted (Novartis Vaccines, Marburg, Germany) vaccine either containing 3.75 μg or 7.5 μg of A/H1N1 California/7/2009 antigen, or nonadjuvanted vaccine containing 7.5 μg or 15 μg of antigen. Antibody titers were assessed by hemagglutination inhibition assay 3 weeks, 3 months and 1 year after immunization. Vaccine safety was monitored throughout the study. After 1 dose, both adjuvanted formulations met the US and EU criteria for seroconversion; the 15 μg nonadjuvanted vaccine met the EU criterion for seroconversion alone. The US and EU criteria for seroprotection were only met by adjuvanted groups. MF59-adjuvanted formulations alone resulted in clinically significant persisting antibody titers after 12 months. All vaccines were well tolerated. A single dose of MF59-adjuvanted vaccine containing 3.75 μg A/H1N1 antigen was highly immunogenic, met both the US and EU licensure criteria and was well tolerated. These data support the suitability of this monovalent vaccine formulation for pandemic use in children 6 to <36 months of age.
    The Pediatric Infectious Disease Journal 04/2012; 31(7):e92-8. DOI:10.1097/INF.0b013e318257644f · 3.14 Impact Factor
  • Stan L Block
    Pediatric Annals 04/2012; 41(4):142-4. DOI:10.3928/00904481-20120307-05 · 0.29 Impact Factor
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    ABSTRACT: Influenza B viruses from 2 lineages cocirculate annually. Because the single B strain contained in trivalent vaccines may not match the major circulating strain, adding a second B virus could enhance protection. This study compared the safety and immunogenicity of an investigational quadrivalent Ann Arbor strain live attenuated influenza vaccine (Q/LAIV) with that of 2 trivalent vaccines (T/LAIV), each containing a B strain from a different lineage. This randomized, double-blind study was designed to demonstrate the immunologic noninferiority of Q/LAIV compared with T/LAIV in children 2-17 years of age by comparing postdose geometric mean titers of hemagglutination inhibition antibodies. Children were randomized 3:1:1 to receive Q/LAIV or 1 of 2 T/LAIV vaccines. Those subjects who were 9-17 years of age received 1 dose, and those 2-8 years of age received 2 doses 1 month apart. Serum immune responses were evaluated 1 month after dose 1 (dose 2 for influenza vaccine-naive subjects aged 2-8 years). Q/LAIV was noninferior to T/LAIV: upper bounds for all four 95% confidence intervals for the postdose geometric mean titer ratios (T/LAIV divided by Q/LAIV) were ≤1.5, the predefined noninferiority margin. The overall seroresponse rates (4-fold rise) were comparable between treatment groups. Safety events were comparable, except that fever was more common after dose 1 in Q/LAIV subjects (5.1%) than in T/LAIV subjects (3.1%) 2-8 years of age. The immunogenicity of Q/LAIV was noninferior to that of T/LAIV in children aged 2-17 years; safety was also comparable. Q/LAIV may broaden the protection against influenza B strains provided by current trivalent influenza vaccines.
    The Pediatric Infectious Disease Journal 03/2012; 31(7):745-51. DOI:10.1097/INF.0b013e31825687b0 · 3.14 Impact Factor
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    ABSTRACT: Background: Acute otitis media (AOM) is a frequent complication of viral infections, including influenza, in young children. Live attenuated influenza vaccine (LAIV) has been shown to help protect against influenza-associated AOM by preventing influenza illness and decreasing the severity of breakthrough influenza illness. LAIV is approved for children 2–17 years of age and is not approved for use in children <24 months of age. Objectives: To estimate the efficacy of LAIV against AOM due to all causes in young children during the influenza season compared with placebo and trivalent inactivated influenza vaccine (TIV) Methods: All-cause AOM incidence for the entire influenza season was calculated for 5 randomized, double-blind, placebo-controlled trials in children 6–47 months of age (LAIV, n=6587; placebo, n=4905) and 2 randomized, double-blind, TIV-controlled trials in children 6–71 months of age (LAIV, n=4966; TIV, n=4971). AOM was diagnosed clinically by the demonstration of a visually abnormal tympanic membrane (with regard to color, position, and/or mobility) suggesting effusion, concomitantly with symptoms of an acute infection. Results: All-cause AOM during the influenza season was diagnosed more frequently in placebo recipients 6–23 months of age than in those 24–47 months of age (15.4% vs 12.3%; P=0.002). The pooled efficacy of LAIV in children 6–71 months of age against all-cause AOM was 16.4% (P<0.001) vs placebo and 9.5% (P=0.02) vs TIV. In children ≥24 months of age, LAIV efficacy against all-cause AOM in the season following vaccination was 20.5% (P=0.007) vs placebo and 7.5% (P=0.29) vs TIV. Conclusions: Among children 6–71 months of age, LAIV substantially reduced the incidence of all-cause AOM during the influenza season compared with placebo and TIV. Sponsored by MedImmune, LLC.
    1st National Immunization Conference Online 2012 Centers for Disease Control and Prevention; 03/2012
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    ABSTRACT: The safety and immunogenicity of the cell-culture-derived seasonal trivalent influenza vaccine ([CCIV]; Optaflu) has been reported previously in adults and the elderly. In this study, we compared the safety, reactogenicity and immunogenicity of CCIV with a conventional egg-derived trivalent influenza vaccine (TIV) in a healthy pediatric population. A total of 3604 subjects were randomized to receive 2 doses of CCIV or TIV (3-8 years, n = 2630) at a 28-day interval or a single vaccination (9-17 years, n = 974). Antibody levels on days 1, 29 and 50 were measured by hemaglutination inhibition assay using egg-derived and cell-derived test antigens. Adverse reactions were solicited via memory aids for 7 days after each injection, and unsolicited adverse events/serious adverse events were collected for 6 months postvaccination. Noninferiority of CCIV versus TIV was demonstrated for most immunogenicity measures, particularly by using cell-derived antigen in the hemaglutination inhibition assay. In 3- to 8-year-olds (the primary objective), both CCIV and TIV met all 3 Committee for Medicinal Products for Human Use immunogenicity criteria for A/H1N1 and A/H3N2 strains. Lower immune responses were observed against the B strain, fulfilling Committee for Medicinal Products for Human Use criteria only for geometric mean ratio (TIV, CCIV) and seroconversion rate (TIV, CCIV [cell-derived antigen]). Both CCIV and TIV were safe and well tolerated, with no differences in local and systemic solicited reactions or in unsolicited adverse events/serious adverse events. CCIV produced in mammalian cell culture is a safe, well-tolerated and immunogenic alternative to conventional egg-derived influenza vaccines for children and adolescents.
    The Pediatric Infectious Disease Journal 02/2012; 31(5):494-500. DOI:10.1097/INF.0b013e31824bb179 · 3.14 Impact Factor

Publication Stats

2k Citations
209.73 Total Impact Points


  • 2001–2014
    • University of Louisville
      • • Department of Pediatrics
      • • Division of Infectious Diseases
      Louisville, Kentucky, United States
  • 2013
    • MedImmune, LLC
      Maryland, United States
  • 2012
    • The Harvard Drug Group
      Ливония, Michigan, United States
  • 2011
    • Oxford Outcomes
      Oxford, England, United Kingdom
  • 2004
    • Abbott Laboratories
      • Abbott Laboratories
      North Chicago, Illinois, United States
  • 1995–1999
    • Creighton University
      • Department of Pediatrics
      Omaha, Nebraska, United States
  • 1997
    • Johns Hopkins University
      Baltimore, Maryland, United States