Can vaccines control bacterial virulence and pathogenicity? Bordetella pertussis: the advantage of fitness over virulence.

Some vaccines, such as diphtheria toxoid and acellular pertussis vaccines (aPVs), may favor the emergence of less pathogenic strains of the respective bacteria they target. This review discusses the impact of the wide use of aPV on Bordetella pertussis phenotype evolutions and their beneficial consequences in the light of the diphtheria toxoid immunization program experience and structuring evidence review in a causal analysis following Bradford Hill's causality criteria. All aPVs contain the pertussis toxin (PT), the main virulence factor of B.pertussis, alone or with one adhesin (filamentous hemagglutinin (FHA)), two adhesins (FHA and pertactin (PRN)) or four adhesins (FHA, PRN and two fimbriae (Fim 2/3)). In countries where the coverage of aPVs containing PRN is high, PRN negative B.pertussis isolates are increasing in prevalence, but isolates nonproducing the other antigens are rarely reported. We hypothesize that the selective pressure at play with PRN should exist against all aVP antigens, although detection biases may hinder its detection for other antigens, especially PT. PT being responsible for clinically frank cases of the disease, the opportunity to collect PT negative isolates is far lower than to collect PRN negative isolates which have a limited clinical impact. The replacement of the current B.pertussis by far less pathogenic isolates no longer producing the factors contained in aPVs should be expected as a consequence of the wide aPV use.

Does monastic life predispose to the risk of Saint Anthony's fire (herpes zoster)?

BACKGROUND: The consequences of the epidemiology of varicella for zoster epidemiology are still debated. We therefore compared the frequency of herpes zoster in an adult population with virtually no varicella zoster virus (VZV) exposure with that in the general population (GP). METHODS: We performed a national, multicenter, observational, exposed versus nonexposed, comparative study. The nonexposed population consisted of members of contemplative monastic orders (CMO) of the Roman Catholic Church living in 40 isolated monasteries in France. The exposed population consisted of a sample of the GP representative of the French population in terms of age group, sex, socio-occupational categories, and regions. RESULTS: The primary analysis population comprised 920 members of CMO (41.5% nuns; mean age, 64.2 years) and 1533 members of the GP (51.9% women; mean age, 64.6 years). The reported frequency of zoster was 16.2% among CMO and 15.1% in the GP (P = .27, adjusted for sex and age). The reported mean age of onset of zoster was 54.8 and 48.6 years, respectively (P = .06). CONCLUSIONS: This study failed to demonstrate an increased risk or earlier onset of zoster in members of CMO not exposed to VZV, compared with that in the GP. Although adults highly exposed to VZV could have a reduced risk of zoster, compared with the GP, our results suggest that the opposite is not true: adults not exposed to VZV are not at increased risk of zoster when compared with the GP, challenging the relevance of the assumptions and forecasts of current epidemiological models.

Human papillomavirus genotype distribution in anal cancer in France: the EDiTH V study.

Anal cancer is a rare cancer but its incidence is increasing. Human papillomavirus (HPV) infection seems to be associated with the occurrence of most cases. The genotype-specific prevalence of HPV in anal cancer was estimated to assess the potential benefit of HPV vaccination in France. Anal cancer histological specimens were retrospectively recruited in 2008 from 16 French centres and centrally tested for HPV genotyping using the INNO-LiPA assay allowing the detection of 28 genotypes. Results were analyzed according to age, gender, HIV status when available and histological diagnosis. A total of 366 anal cancer cases were analyzed among which 62% were females. Mean age at diagnosis was 54.8 years in males and 66.4 years in females (p < 0.001). HPV was found in 96.7% of cases, 72% being infected by a single HPV type. Presence of at least one high-risk genotype was observed in 91% of cases (96% in females and 83% in males; p < 0.001). HPV16 was by far the most prevalent genotype (75%), followed by HPV18, HPV52, HPV33, and HPV51 (4-6%). HPV16/18 alone or in association were found in 78% of all cases. HIV-positive cases had a higher proportion of multiple HPV infection than HIV-negative cases and a slightly different HPV type distribution with an under-representation of HPV16 and an over-representation of other types. Our results indicate that anal cancer rarely occurs in the absence of HPV and emphasize the predominant role of HPV16. The potential benefit of HPV vaccine on the occurrence of anal cancer should be further evaluated.

Inverse correlation between varicella severity and level of anti-Varicella Zoster Virus maternal antibodies in infants below one year of age.

Varicella, a widespread disease of childhood, is usually benign but may in some instances lead to complications and eventually death. The aim of this study was to assess whether varicella severity in infants below one year of age was associated with the level of anti-varicella zoster virus (VZV) maternal antibodies. Two different data sets were used. Data on varicella-associated complications were collected through a national surveillance network involving 175 hospital-based pediatric wards. Data on levels of maternal acquired antibodies according to infants' age were extracted from a cohort of 345 full term infants enrolled in a prospective multicenter study in seven pediatric wards and/or pediatric emergency units. Among infants hospitalized for varicella complications, the overall prevalence of complications increased regularly from 10.4% in infants below 1 month of age to over 72.4% at 5 months of age. Conversely, the mean antibody titre decreased from 536 mIU/mL in the [0-1 [month group to below the 150 mIU/mL threshold at 3-4 months [Pearson coefficient = -0.956 (p < 0.001)]. Based on large numbers of infants, our results show for the first time, a strong inverse correlation between the levels of circulating anti-VZV maternal antibodies in full term infants and occurrence of varicella complications below one year of age. Infant protection could be optimized by increasing herd immunity, reducing the susceptibility of women in childbearing age and lowering the age of routine vaccination to 9 months. Additional vaccination for unprotected persons in close contact with infants below 12 months of age could be promoted.

Immunogenicity and safety of combined adsorbed low-dose diphtheria, tetanus and inactivated poliovirus vaccine (REVAXIS (®)) versus combined diphtheria, tetanus and inactivated poliovirus vaccine (DT Polio (®)) given as a booster dose at 6 years of age.

This randomized, comparative, phase-IIIb study conducted in France aimed to demonstrate whether seroprotection against diphtheria, tetanus and poliomyelitis 1 month after a single dose of REVAXIS (low-dose diphtheria) is non-inferior to seroprotection 1 month after a single dose of DT Polio (standard-dose diphtheria), both vaccines being given as a second booster to healthy children at 6 years of age. Children were randomly assigned to receive a single intramuscular dose of REVAXIS or DT Polio. Primary endpoints were the 1-month post-booster seroprotection rates for diphtheria, tetanus and poliovirus type-1, -2 and -3 antigens. Secondary endpoints were immunogenicity and safety observations. Of 788 children screened, 760 were randomized: REVAXIS group, 384 children; DT Polio group, 376 children. No relevant difference in demographic characteristics at baseline was observed between REVAXIS and DT Polio groups. Non-inferiority of REVAXIS compared with DT Polio for seroprotection was demonstrated against diphtheria (respectively 98.6% and 99.3%), tetanus (respectively 99.6% and 100%), and poliovirus antigens (100% for each types in both groups). No allergic reactions to REVAXIS were reported. A benefit/risk ratio in favor of REVAXIS was suggested by the trend towards a better tolerability of REVAXIS compared with DT Polio regarding the rate of severe solicited injection-site reactions. The results support the use of REVAXIS as a booster at 6 years of age in infants who previously received a three-dose primary series within the first 6 months of life and a first booster including diphtheria, tetanus and poliovirus vaccine(s) given before 2 years of age.

Hospitalization of newborns and young infants for chickenpox in France.

Chickenpox is often considered more severe during the first year of life, but its course is usually mild during the first 3 months of life, presumably owing to the persistence of maternal antibodies. Hospitalization and intravenous acyclovir therapy are generally restricted to severe cases but also systematically recommended in newborns in France, irrespective of the clinical severity of the infection. This recommendation was launched in 1998 when Varicella zoster virus (VZV)-specific immunoglobulins were not available in the country and has remained unchanged since. The aim of this prospective observational study was to describe complications of varicella infection in a population of 745 children hospitalized for varicella before 1 year of age, with a specific focus on newborns. Complications occurred in 65% of cases. They were very rare before the age of 1 month (10%) but their incidence then increased progressively with age and probably the disappearance of maternal antibodies: 42% (1-2 months), 66% (3-5 months), 70% (6-8 months), and 79% (9-12 months). Conclusion Chickenpox is usually mild in newborns because most of them are protected by VZV maternal antibodies. Unless the absence of maternal VZV immunity is demonstrated, newborns with mild chickenpox should not require antiviral therapy.

Humoral immunity of dTap-IPV vaccine (REPEVAX®) administered one month after dT-IPV vaccine (REVAXIS®) in adults with unknown vaccination history.

This study was to assess the humoral immune response induced by a vaccination schedule routinely used in France in 18-50 year old adults with unknown vaccination history. In this monocentric, prospective study, subjects received one dose of REVAXIS® (dT-IPV, diphtheria, tetanus and poliomyelitis (inactivated) vaccine (adsorbed, reduced antigen(s) content)) (Visit 1) followed by one dose of REPEVAX® (dTap-IPV, diphtheria, tetanus, pertussis (acellular, component) and poliomyelitis (inactivated) vaccine (adsorbed, reduced antigen(s) content)) one month later (Visit 2). Antibodies against diphtheria, tetanus, poliomyelitis types 1, 2 and 3, and pertussis toxin (PT) were measured one month after the administration of REPEVAX® (Visit 3). A total of 136 subjects were included in the study, but blood samples were available for only 73 subjects. Their mean age at inclusion was 33.2 ± 7.3 years. 49.3% of the 73 subjects originated from the WHO African Region, 6.8% from the WHO Western Pacific Region and 5.5% from the WHO European Region. One month after REPEVAX® administration, all subjects had seroprotective antibody titers against diphtheria and tetanus (≥0.1 IU/mL), poliomyelitis types 2 and 3 (≥ 8 1/dil); one subject (1.4%) did not have antibodies against poliomyelitis type 1. The rate of anti-PT seropositivity (≥8 EU/mL) was 94.4%. One dose of REPEVAX® administered one month after a dose of REVAXIS® in subjects with unknown vaccination history induced a high humoral response. These results validate a vaccination schedule routinely used for years that rapidly elicits effective immunization against diphtheria, tetanus, poliomyelitis and pertussis.

Safety of Tdap-IPV given one month after Td-IPV booster in healthy young adults: a placebo-controlled trial.

BACKGROUND: In France, the only vaccines available for use as a pertussis booster in adults are combined vaccines containing adsorbed tetanus, diphtheria (adult formulation), acellular pertussis and inactivated poliovirus (Tdap-IPV). Adults may require a pertussis booster relatively soon after having received vaccines containing tetanus-diptheria antigens (Td) (occupational or familial circumstances such as new job, childbirth in recent past or future), although the safety of Tdap-IPV when administered soon after vaccination with Td is undocumented. METHODS: In this randomized, double-blind, multi-centre study, we assessed the safety of Tdap-IPV administered one month after vaccination with tetanus, diphtheria (adult formulation), inactivated poliovirus vaccination (Td-IPV) in healthy adults vaccinated according to the French vaccination calendar (seven tetanus-diphtheria vaccinations by age 18 years). Subjects received either Td-IPV (n = 249) or placebo (n = 251) followed 1 month later by Tdap-IPV. Any adverse events (AEs) were recorded. RESULTS: The safety of Tdap-IPV was similar when Tdap-IPV vaccine was administered one month after either Td-IPV or placebo: at seven days, 85.1% versus 93.4% subjects reported at least one reaction at the injection site, mainly pain (82.6% versus 92.1%); 40.5% versus 45.0%, at least one systemic AE (mainly headache: 26.4% versus 26.0%); fever concerned 1.7% of both groups. No serious vaccine-related AEs were reported. Both safety profiles corresponded to documented product characteristics. CONCLUSIONS: Tdap-IPV may be administered to adults one month after Td-IPV without exacerbating post-vaccination side-effects.

Immunogenicity and safety of intramuscular versus subcutaneous administration of a combined measles, mumps, rubella, and varicella vaccine to children 12 to 18 months of age.

This randomized trial conducted in France compared intramuscular (IM) and subcutaneous (SC) administration of two doses of a measles, mumps, rubella, and varicella (MMRV) combination vaccine (ProQuad®) administered one month apart to 405 children 12-18 months of age (NCT00402831). The 2-dose regimen of MMRV administered IM was shown to be as immunogenic as the 2-dose regimen administered SC for all antigens 6 weeks post-vaccination for the subjects who were initially seronegative for measles, mumps, rubella, or varicella (lower bounds of the two-sided 95% CIs for the difference in response rates for all antigens greater than -10% [range -2.1 for varicella to -3.0 for mumps]). The antibody response rates for all vaccine antigens 6 weeks after the second dose of MMRV were > 99% in both the IM and SC groups. Fewer subjects in the IM group experienced injection-site AEs compared with the SC group (17.8% and 28.6% post-dose 1, and 20.4% and 29.5% post-dose 2, respectively). From Day 0 to Day 4 post-dose 2, fewer subjects reported erythema and swelling in the IM group than in the SC group (15.4% and 27.0%, and 6.0% and 12.5%, respectively). In both groups, most injection-site AEs started during the first four days after vaccination; their intensity was mainly mild or ≤2.5 cm. The rates of fever were comparable between the two groups after each dose of MMRV. In conclusion, two doses of the MMRV vaccine were highly immunogenic and well tolerated when administered either SC or IM. ClinicalTrials.gov Identifier: NCT00402831.

Human papillomavirus genotype distribution in external acuminata condylomata: a Large French National Study (EDiTH IV).

BACKGROUND: External acuminata condylomata (EAC) are among the most common sexually transmitted diseases. Although it is understood that low-risk human papillomavirus (HPV) genotypes 6 and 11 are associated with EAC, there have only been a few, small, published studies reporting the genotype-specific prevalence of HPV. The objective of our study was to assess the prevalence of HPV genotypes for a large number of cases involving both men and women and to evaluate the potential benefit of a quadrivalent (genotypes 6, 11, 16, and 18) HPV vaccine in France. METHODS: A total of 256 women and 260 men who presented with EAC to French gynecologists, dermatologists, and proctologists were prospectively recruited during the period January through April 2007. Specimens were collected with a cytobrush, and the HPV genotype was determined using the INNO-LiPA assay (Innogenetics), which detects 24 HPV genotypes. RESULTS: Four hundred twenty-three beta-globin-positive samples could be analyzed. The median age of patients was 30 years (range, 18-72 years). The overall prevalence of HPV DNA in patients with EAC was 99% (33% of patients were coinfected with another pathogen). Low-risk genotypes predominated, with a prevalence of 89%. The most prevalent genotypes were 6 (69%) and 11 (16%), followed by 16 (9%), 51 (8%), 52 (7%), 66 (6%) 53 (5%), 31 (3%), and 18 (3%). The cumulative prevalence of genotypes 6 and 11 was 83%, and the cumulative prevalence of genotypes 6, 11, 16, and 18 was 88%. CONCLUSIONS: This study is, to our knowledge, the first large, multicenter survey to provide solid data on HPV genotype distribution among patients with EAC. Our results provide strong evidence that, in France, the most prevalent HPV genotypes in persons with EAC are 6 and 11. Because of its 99% efficacy for the prevention of EAC and a vaccine coverage of 100%, the quadrivalent HPV vaccine could prevent 62%-87% of EAC cases in France.

Human papillomavirus (HPV) genotype distribution in invasive cervical cancers in France: EDITH study.

Invasive cervical cancer (ICC) remains a significant cause of morbidity and mortality in France. Since human papillomavirus (HPV) is the necessary cause of ICC, the aim of this study was to assess the type-specific prevalence of HPV in ICC in France in order to locally evaluate the potential benefit of an HPV 16/18 L1 virus-like particles (VLP) vaccination. A total of 516 histological specimens collected in 15 centers were analyzed. Among them, 86% had a diagnosis of squamous cell carcinoma (SCC) whereas 14% were adenocarcinomas (ADC). HPV genotyping was performed using the INNO-LiPA assay allowing the specific detection of 24 HPV genotypes both high risk (HR) and low risk (LR). The overall HPV prevalence in ICC was 97%. The most prevalent genotypes were HPV 16 (73%) and HPV 18 (19%) followed by HPV 31 (7%), 33, 68, 45, 52 and 58 (4.1-2.3%). HPV 16 and/or 18 were associated with 82% of ICC, 10% being HPV 16 and 18 coinfections. While HPV 16 was the most prevalent type in both SCC (74%) and ADC (64%), HPV 18 was by far more prevalent in ADC (37%) compared to SCC (16%; p < 0.001). Multiple infections with at least two different HR HPV genotypes were observed in 22% of ICC. Given the high HPV 16/18 prevalence and taking into account possible production of crossneutralizing antibodies against other HPV types, HPV 16/18 L1 VLP vaccination would be expected to significantly reduce the burden of ICC in France.

Human papillomavirus genotype distribution in high grade cervical lesions (CIN 2/3) in France: EDITH study.

High grade cervical intraepithelial neoplasia (CIN 2/3) have a high potential to progress to invasive cervical cancer (ICC). Pap testing including follow-up and treatment of CIN 2/3 is currently the best prevention of ICC, but is associated with morbidity, namely obstetrical adverse effects and psychological distress. Human papillomavirus (HPV) is universally accepted as the necessary cause of ICC. The objective of the present study was to describe the type-specific prevalence of HPV in CIN 2/3 in France and hereby to locally estimate the potential benefit of an HPV 16/18 L1 virus-like particles (VLP) vaccine. A total of 493 formalin-fixed and paraffin-embedded CIN 2/3 specimens were analyzed. Medical records were examined for patient related data. HPV were genotyped with the INNO-LiPA assay allowing the detection of 24 HPV genotypes. The overall prevalence of LiPA detectable HPV was 98%. The most prevalent genotype was HPV 16 (62%) followed by HPV 31 (15%), 33 (12%), 52 (9%), 51 (8%), 58 (7%), 35 and 18 (4%). Multiple infection with at least two different high-risk (HR) HPV genotypes was observed in 26% of all specimens including 2.6% with HPV 16 and 18 multiple infections. The present study indicates that HPV 16 is by far the most common HPV type associated with CIN 2/3 in France. With an HPV 16 and 18 prevalence of 64%, HPV 16/18 L1 VLP vaccines would be expected to significantly reduce the burden associated with the management and treatment of CIN 2/3 in France.

Human papillomavirus genotype distribution in low-grade squamous intraepithelial lesions in France and comparison with CIN2/3 and invasive cervical cancer: the EDiTH III study.

OBJECTIVES: In the present study (EDiTH III study), the genotype-specific prevalence of HPV in low-grade squamous intraepithelial lesions (LSIL) was estimated to predict the potential benefit of HPV vaccination in France. This prevalence was compared to that previously reported in France in high-grade cervical intraepithelial neoplasia (CIN2/3, EDiTH II study) and squamous cell carcinoma (SCC, EDiTH I study) to identify the genotypes preferentially associated with a progression to malignancy. METHODS: 397 smears with LSIL diagnosis (Preservcyt) were retrospectively collected in different centres in France and genotyped using the INNO-LiPA assay allowing the detection of 24 HPV genotypes. RESULTS: HPV was found in 98% of cases. The most prevalent genotypes in LSIL in France were HPV 66 (25%), HPV 16 (21%), HPV 53 (18%), 51 (17%) and 52 (14%). HPV 16 and/or 18 were present in 28% and HPV 6, 11, 16 and/or 18 in 33% of LSIL. The highest SCC/LSIL prevalence ratios were shown for HPV 16, 33 and 18. CONCLUSIONS: With a 95% vaccine efficacy on CIN1 and theoretical vaccine coverage of 100%, HPV vaccination might prevent 27% (with a 16, 18 bivalent vaccine) and up to 32% (with a 6, 11, 16, 18 quadrivalent vaccine) of LSIL cases in France. In this study, LSIL related to HPV 16, 18 or 33 are at highest risk of progression to malignancy and thus could require a stringent surveillance. Conversely, anxiety and over-treatment could be avoided in women with low risk of progression.

Estimation of the individual residual risk of cervical cancer after vaccination with the nonavalent HPV vaccine.

BACKGROUND: The nonavalent HPV (9vHPV) vaccine is indicated for active immunisation of individuals from the age of 9 years against cervical, vulvar, vaginal and anal premalignant lesions and cancers causally related to vaccine HPV high risk types 16, 18, 31, 33, 45, 52 and 58, and to the HPV low risk types 6 and 11, causing genital warts. OBJECTIVE: To estimate the lifetime risk (up to the age of 75 years) for developing cervical cancer after vaccinating a HPV naïve girl (e.g. 9 to 12 years old) with the 9vHPV vaccine in the hypothetical absence of cervical cancer screening. METHODS: We built Monte Carlo simulation models using historical pre-screening age-specific cancer incidence data and current mortality data from Denmark, Finland, Norway, Sweden and the UK. Estimates of genotype contribution fractions and vaccine efficacy were used to estimate the residual lifetime risk after vaccination assuming lifelong protection. RESULTS: We estimated that, in the hypothetical absence of cervical screening and assuming lifelong protection, 9vHPV vaccination reduced the lifetime cervical cancer and mortality risks 7-fold with a residual lifetime cancer risks ranging from 1/572 (UK) to 1/238 (Denmark) and mortality risks ranging from 1/1488 (UK) to 1/851 (Denmark). After decades of repetitive cervical screenings, the lifetime cervical cancer and mortality risks was reduced between 2- and 4-fold depending on the country. CONCLUSION: Our simulations demonstrate how evidence can be generated to support decision-making by individual healthcare seekers regarding cervical cancer prevention.

The public health value of vaccination for seniors in Europe.

Longer life expectancy and decreasing fertility rates mean that the proportion of older people is continually increasing worldwide, and particularly in Europe. Ageing is associated with an increase in the risk and severity of infectious diseases. These diseases are also more difficult to diagnose and manage in seniors who often have at least one comorbid condition (60% of seniors have two or more conditions). Infectious diseases increase the risk of hospitalization, loss of autonomy and death in seniors. Effective vaccines are available in Europe for infectious diseases such as influenza, pneumococcal diseases, herpes zoster, diphtheria, tetanus and pertussis. Their effectiveness has been demonstrated in terms of reducing the rates of hospitalization, disability, dependency and death. The prevention of diseases in seniors also results in savings in healthcare and societal costs each year in Europe. Despite the availability of vaccines, vaccine-preventable diseases affect millions of European citizens annually, with the greatest burden of disease occurring in seniors, and the medical and economic benefits associated with are not being achieved. Vaccination coverage rates must be improved to achieve the full benefits of vaccination of seniors in Europe.

Safety and immune response to a challenge dose of hepatitis B vaccine in healthy children primed 10years earlier with hexavalent vaccines in a 3, 5, 11-month schedule: An open-label, controlled, multicentre trial in Italy.

BACKGROUND AND AIMS: The strategy of vaccinating infants to prevent hepatitis B virus infection in adolescence or adulthood requires durable immunity. This study investigated responses to a challenge dose of monovalent hepatitis B vaccine in children primed with three doses of either Hexavac® or Infanrix hexa® 10years earlier during infancy. METHODS: This open-label, controlled, multicentre study conducted in Italy, enrolled 751 healthy pre-adolescents (aged 11-13years) who were given either Hexavac (n=409) or Infanrix hexa (n=342) at 3, 5 and 11months of life. All participants received a challenge dose of a monovalent hepatitis B vaccine (HBVaxPro® 5µg). The concentrations of antibodies to hepatitis B surface antigen (anti-HBs) were measured before and 1month after the challenge dose. The analysis was descriptive and no formal hypothesis was tested. RESULTS: One month post-challenge, 331 participants in the Hexavac cohort [83.6%, 95% CI: 79.6; 87.1] and 324 in the Infanrix hexa cohort [96.4%, 95% CI: 93.8; 98.1] had anti-HBs concentrations ≥10mIU/mL. Before the challenge dose, an anti-HBs concentration of ≥10mIU/mL was found in 94 children in the Hexavac cohort [23.9%, 95% CI: 19.7; 28.4] and in 232 children in the Infanrix hexa cohort [69%, 95% CI: 63.8; 74.0]. Among children with a pre-challenge anti-HBs concentration of <10mIU/mL, 236 [78.7%, 95% CI: 73.6; 83.2] in the Hexavac cohort and 92 [88.5%, 95% CI: 80.7; 93.9] in the Infanrix hexa cohort achieved protective anti-HBs antibody concentrations. No evidence of active hepatitis B disease was observed in either group, and the HBVaxPro challenge dose was well tolerated. CONCLUSIONS: These data confirm that immune memory persists in a high percentage of children (>80%) at least 10years after a two-dose primary and booster vaccination schedule with a hexavalent vaccine (Hexavac or Infanrix hexa). TRIAL REGISTRATION: EudraCT Number: 2013-001602-28; clinicaltrials.gov: NCT02012998.

Manufacturing DTaP-based combination vaccines: industrial challenges around essential public health tools.

INTRODUCTION: The manufacture of DTP-backboned combination vaccines is complex, and vaccine quality is evaluated by both batch composition and conformance of manufacturing history. Since their first availability, both the manufacturing regulations for DTP combination vaccines and their demand have evolved significantly. This has resulted in a constant need to modify manufacturing and quality control processes. Areas covered: Regulations that govern the manufacture of complex vaccines can be inconsistent between countries and need to be aligned with the regulatory requirements that apply in all countries of distribution. Changes in product mix and quantities can lead to uncertainty in vaccine supply maintenance. These problems are discussed in the context of the importance of these products as essential public health tools. Expert commentary: Increasing demand for complex vaccines globally has led to problems in supply due to intrinsically complex manufacturing and regulatory procedures. Vaccine manufacturers are fully engaged in the resolution of these challenges, but currently changes in demand need ideally to be anticipated approximately 3 years in advance due to long production cycle times.

Potential impact of the human papillomavirus vaccine on the incidence proportion of genital warts in French women (EFFICAE study): a multicentric prospective observational study.

UNLABELLED: Background The objective was to evaluate the effect of a HPV vaccination program on the incidence proportion of a proxy, genital warts (GW), in women in France. METHODS: The number of primary GW cases was prospectively recorded over two 4-month periods before (T0: Dec 2008 to March 2009) and after (T1: Dec 2011 to March 2012) a HPV vaccination program. A total of 160 gynaecologists participated in T0 and 189 in T1. Primary genital herpes (HSV) infection was used as a control. RESULTS: During T0, 39190 15- to 26 year-old women were seen, of whom 176 were diagnosed with GW (incidence proportion: 0.45%) and 155 with primary HSV infection (incidence proportion: 0.39%). During T1, 45628 females were seen [229 with GW (incidence proportion: 0.50%) and 202 with HSV (incidence proportion: 0.44%)]. In the 15-20 years age category, the incidence proportion of primary GW decreased from 0.41% to 0.30% (P=0.128) between T0 and T1, and the proportion of women newly diagnosed with primary genital herpes diseases slightly increased from 0.34% to 0.38% (P=0.620). In the 15-18 years age group, this decrease became significant (0.34% to 0.18%; P=0.048). CONCLUSIONS: A trend for a non-significant decreased incidence proportion of GW was observed in young women below 20 years who are more frequently vaccinated. This may be the result of HPV vaccination and suggests that a substantial increase in vaccine coverage could lead to a more pronounced decreased incidence proportion of GW in the future.

Use of the nonavalent HPV vaccine in individuals previously fully or partially vaccinated with bivalent or quadrivalent HPV vaccines.

With the availability of the nonavalent human papillomavirus (HPV) vaccine, vaccinees, parents and healthcare providers need guidance on how to complete an immunization course started with the bi- or quadrivalent vaccine and whether to revaccinate individuals who have completed a full immunization course with the bi- or quadrivalent vaccine. To answer these questions three parameters should be considered: age at the start of vaccination (9 to 14 years of age versus 15 years and older, the cut-off for 2 or 3 doses schedule), the number of doses already received and the time interval between doses. Based on a number of scenarios, we propose that the 9-valent vaccine can be used to complete an incomplete vaccination regimen or might be added to a previous completed schedule to extend protection.

Vaccination of adults with 23-valent pneumococcal polysaccharide vaccine induces robust antibody responses against pneumococcal serotypes associated with serious clinical outcomes.

PNEUMOVAX™ 23, a 23-valent polysaccharide pneumococcal vaccine (PPV23), covers 65% to 91% of the isolates recovered from adult cases of invasive pneumococcal disease. Several studies have demonstrated that pneumococcal serotypes 31, 11A, 35F, 17F, 3, 16F, 19F, 15B, and 10A are associated with higher case-fatality or meningitis rates than other pneumococcal serotypes. This study (U05-PnPS-403; EudraCT: 2008-003648-12) evaluated the immune response followings administration of PPV23 for 4 of these serotypes (10A, 11A, 15B, and 17F), that are included in PPV23 but not in licensed pneumococcal conjugate vaccines. Serotype-specific IgG geometric mean concentrations (GMCs) and geometric mean fold-rises (GMFRs) for these 4 serotypes were measured by a validated enzyme-linked immunosorbent assay (ELISA) in 104 subjects >50 y of age who were enrolled in a study evaluating the safety and immunogenicity of a single-dose of PPV23. At 1 month post-vaccination, GMCs for serotypes10A, 11A, 15B and 17F were 6.5, 4.3, 14.7, and 5.1 µg/mL, respectively. GMFRs from baseline were 9.0, 4.5, 8.4, and 11.5, respectively. The percentages of subjects achieving >2-fold increases in IgG GMCs between pre-vaccination and 1 month post-vaccination were 90%, 85%, 88% and 89%, respectively. In conclusion, PPV23 induces a robust immune response in adults to pneumococcal serotypes 10A, 11A, 15B, and 17F, which have been associated with elevated case-fatality or meningitis rates.