Ten-year follow-up on efficacy, immunogenicity and safety of two doses of a combined measles-mumps-rubella-varicella vaccine or one dose of monovalent varicella vaccine: Results from five East European countries

BACKGROUND

We assessed the 10-year efficacy, immunogenicity and safety of two doses of a combined measles-mumps-rubella-varicella vaccine (MMRV) or one dose of a monovalent varicella vaccine (V) in children from Czech Republic, Lithuania, Poland, Romania and Slovakia.

METHODS

This was a phase IIIB follow-up of an observer-blind, randomized, controlled trial (NCT00226499). In phase A, healthy children aged 12-22 months from 10 European countries were randomized in a 3:3:1 ratio to receive two doses of MMRV (MMRV group), one dose of MMR followed by one dose of V (MMR + V group), or two doses of MMR (MMR; control group), 42 days apart. Vaccine efficacy (VE) against varicella (confirmed by viral DNA detection or epidemiological link and clinical assessment) was calculated with 95% confidence intervals using Cox proportional hazards regression model. Immunogenicity was assessed as seropositivity rates and geometric mean concentrations (GMCs). Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded.

RESULTS

A total of 3705 children were vaccinated (1590, MMRV group; 1586, MMR + V group; 529, MMR group). There were 663 confirmed varicella cases (47, MMRV group; 349, MMR + V group; 267, MMR group). VE ranged between 95.4% (Lithuania) and 97.4% (Slovakia) in the MMRV group and between 59.3% (Lithuania) and 74% (Slovakia) in the MMR + V group. At year 10, seropositivity rates were 99.5%-100% in the MMRV group, 98%-100% in the MMR + V group and 50%-100% in the MMR control group, and the anti-VZV antibody GMCs were comparable between MMRV and MMR + V groups. The occurrence of solicited and unsolicited AEs was similar across groups and no SAE was considered as vaccination-related. No new safety concerns were identified.

CONCLUSIONS

Our results indicated that two doses of varicella zoster virus-containing vaccine provided better protection than one dose against varicella and induced antibody responses that persisted 10 years post-vaccination.

Immune Responses to a Recombinant Glycoprotein E Herpes Zoster Vaccine in Adults Aged 50 Years or Older

Background

The herpes zoster subunit vaccine (HZ/su), consisting of varicella-zoster virus glycoprotein E (gE) and AS01_B Adjuvant System, was highly efficacious in preventing herpes zoster in the ZOE-50 and ZOE-70 trials. We present immunogenicity results from those trials.

Methods

Participants (ZOE-50: ≥50; ZOE-70: ≥70 years of age) received 2 doses of HZ/su or placebo, 2 months apart. Serum anti-gE antibodies and CD4 T cells expressing ≥2 of 4 activation markers assessed (CD4²⁺) after stimulation with gE-peptides were measured in subcohorts for humoral (n = 3293) and cell-mediated (n = 466) immunogenicity.

Results

After vaccination, 97.8% of HZ/su and 2.0% of placebo recipients showed a humoral response. Geometric mean anti-gE antibody concentrations increased 39.1-fold and 8.3-fold over baseline in HZ/su recipients at 1 and 36 months post-dose 2, respectively. A gE-specific CD4²⁺ T-cell response was shown in 93.3% of HZ/su and 0% of placebo recipients. Median CD4²⁺ T-cell frequencies increased 24.6-fold (1 month) and 7.9-fold (36 months) over baseline in HZ/su recipients and remained ≥5.6-fold above baseline in all age groups at 36 months. The proportion of CD4 T cells expressing all 4 activation markers increased over time in all age groups.

Conclusions

Most HZ/su recipients developed robust immune responses persisting for 3 years following vaccination.

Clinical Trials Registration

NCT01165177; NCT01165229.

Medical conditions at enrollment do not impact efficacy and safety of the adjuvanted recombinant zoster vaccine: a pooled post-hoc analysis of two parallel randomized trials

In two pivotal efficacy studies (ZOE-50; ZOE-70), the adjuvanted recombinant zoster vaccine (RZV) demonstrated >90% efficacy against herpes zoster (HZ).Adults aged ≥50 or ≥70 years (ZOE-50 [NCT01165177]; ZOE-70 [NCT01165229]) were randomized to receive 2 doses of RZV or placebo 2 months apart. Vaccine efficacy and safety were evaluated post-hoc in the pooled (ZOE-50/70) population according to the number and type of selected medical conditions present at enrollment.At enrollment, 82.3% of RZV and 82.7% of placebo recipients reported ≥1 of the 15 selected medical conditions. Efficacy against HZ ranged from 84.5% (95% Confidence Interval [CI]: 46.4-97.1) in participants with respiratory disorders to 97.0% (95%CI: 82.3-99.9) in those with coronary heart disease. Moreover, efficacy remained >90% irrespective of the number of selected medical conditions reported by a participant.As indicated by the similarity of the point estimates, this post-hoc analysis suggests that RZV efficacy remains high in all selected medical conditions, as well as with increasing number of medical conditions. No safety concern was identified by the type or number of medical conditions present at enrollment.

Protection against varicella with two doses of combined measles-mumps-rubella-varicella vaccine or one dose of monovalent varicella vaccine: 10-year follow-up of a phase 3 multicentre, observer-blind, randomised, controlled trial

BACKGROUND

The duration of protection provided by varicella vaccines is unclear. We assessed the 10-year vaccine efficacy of two doses of a combined measles-mumps-rubella-varicella vaccine (MMRV), one live attenuated varicella vaccine (V) dose given after one measles-mumps-rubella vaccine (MMR) dose (MMR + V), versus two MMR doses (control vaccine) for the prevention of confirmed varicella.

METHODS

This was a phase 3b follow-up of an observer-blinded, randomised, controlled trial. In phase a, children aged 12-22 months (at first vaccination) from Czech Republic (Czechia), Greece, Italy, Lithuania, Norway, Poland, Romania, Russia, Slovakia, and Sweden were randomly assigned by computer-generated randomisation list (3:3:1) to receive two doses of MMRV, one dose of MMR and one dose of varicella vaccine, or two doses of MMR, 42 days apart. Varicella cases were confirmed by detection of viral DNA, or epidemiological link and clinical assessment, by an independent data monitoring committee; disease severity was based on a modified Vázquez scale. Hazard ratios for MMRV and MMR + V versus MMR estimated in the per-protocol cohort using a Cox proportional hazards regression model were used to calculate vaccine efficacy and 95% CI. Serious adverse events were recorded throughout the study in all vaccinated children. Study objectives were secondary and descriptive. The trial is registered at ClinicalTrials.gov, number NCT00226499.

FINDINGS

Between Sept 1, 2005, and May 10, 2006, 5803 children (mean age 14·2 months, SD 2·5) were vaccinated. The per-protocol cohort included 2279 children from the MMRV group, 2266 from the MMR + V group, and 744 from the MMR group. From baseline to a median follow-up of 9·8 years, 76 (3%) children in the MMRV group, 469 (21%) in the MMR + V group, and 352 (47%) in the MMR group had varicella. Vaccine efficacy against all varicella was 95·4% (95% CI 94·0-96·4) for MMRV and 67·2% (62·3-71·5) for MMR + V; vaccine efficacy against moderate or severe varicella was 99·1% (97·9-99·6) for MMRV and 89·5% (86·1-92·1) for MMR + V. During phase b, serious adverse events were reported by 290 (15%) of 1961 children in the MMRV group, 317 (16%) of 1978 in the MMR + V group, and 93 (15%) of 641 in the MMR group. There were no treatment-related deaths.

INTERPRETATION

The 10-years vaccine efficacy observed, suggests that a two-dose schedule of varicella vaccine provided optimum long-term protection for the prevention of varicella by offering individual protection against all severities of disease and leading to a potential reduction in transmission, as observed in the US experience with universal mass vaccination.

FUNDING

GlaxoSmithKline Biologicals.

Persistence of immune response to an adjuvanted varicella-zoster virus subunit vaccine for up to year nine in older adults

Background: In adults aged ≥60 years, two doses of the herpes zoster subunit vaccine (HZ/su; 50 µg varicella-zoster virus glycoprotein E [gE] and AS01_B Adjuvant System) elicited humoral and cell-mediated immune responses persisting for at least six years. We assessed immunogenicity nine years post-initial vaccination.

Methods: This open extension study (NCT02735915) followed 70 participants who received two HZ/su doses in the initial trial (NCT00434577). Blood samples to assess the cellular (intracellular cytokine staining) and humoral (ELISA) immunity were taken at year nine post-initial vaccination.

Results: Participants' mean age at dose 1 was 72.3 years. The fold increases over pre-vaccination in the mean frequency of gE-specific CD4+ T-cells expressing ≥2 activation markers plateaued from year four post-dose 1 until year nine. Anti-gE antibody geometric mean concentrations plateaued and remained above pre-vaccination levels from year four onwards. Immunogenicity at year nine was similar across age strata (60–69, ≥70 years) and confirmed statistical prediction model results using data for up to year six. Further modeling using all data up to year nine predicted immune responses would remain above the pre-vaccination level up to year 15.

Conclusion: In adults aged ≥60 years, HZ/su-induced immunogenicity remained above pre-vaccination levels for at least nine years post-initial vaccination.

Summary: After vaccination with HZ/su, both cell mediated and humoral immunity remained above pre-vaccination levels up to year 9 regardless of age group. Immune responses are predicted to remain above baseline up to 15 years post initial vaccination.

Influenza vaccination in the elderly

Seasonal influenza is a prevalent and serious annual illness resulting in widespread morbidity and economic disruption throughout the population; the elderly and immunocompromised are particularly vulnerable to serious sequelae and mortality. The changing demographics worldwide to an aging society have important implications for public health policy and pharmaceutical innovations. For instance, primary prevention via immunization is effective in reducing the burden of influenza illness among the elderly. However, the elderly may be insufficiently protected by vaccination due to the immunosenescence which accompanies aging. In addition, vaccine hesitancy among the younger populations increases the likelihood of circulating infectious diseases, and thus concomitant exposure. While it is clear that the development of more immunogenic vaccines is an imperative and worthy endeavor, clinical trials continue to demonstrate that the current influenza vaccine formulation remains highly effective in reducing morbidity and mortality when well matched to circulating strains.

Serological survey of mumps antibodies in adults in the Czech Republic and the need for changes to the vaccination strategy

Mumps outbreaks, especially in adolescents and young adults, have been reported in the Czech Republic. The aim of the presented study was to determine the seroprevalence of specific IgG antibodies against mumps in the adult population of the Czech Republic. The study was designed as a multicenter serological survey of adults aged 18 years and over. Specific IgG antibodies against mumps were detected in blood samples using an enzyme-linked immunosorbent assay (ELISA). A total of 1,911 serum samples were examined. The overall seropositivity reached 55.3%. In individual age groups, the highest seropositivity 63% (63.5-65.2%) was recorded in adults aged 40 years and over; the lowest seropositivity was found in adults aged 18-29 years (27.4%). The difference in seropositivity rate between the 18-29 years age group and the 40 years and over age groups was statistically significant (p < 0.001). Only the 18-29 years age group included both vaccinated and unvaccinated (born in the pre-vaccine era) individuals. In vaccinated individuals, seropositivity was reported in only 19.1% of persons; in unvaccinated individuals, seropositivity reached 48.2%. Our results demonstrate the long-term persistence of antibodies following natural infection and the decrease in seropositivity that occurs after vaccination over time. This immunity waning may account for the higher susceptibility of adolescents and young adults to mumps. Therefore, the current vaccination program in the Czech Republic could be considered as less effective. It will be modified with the shifting of the second dose of vaccine from two years of age to the preschool age.

Seroepidemiology of whooping cough in the Czech Republic: estimates of incidence of infection in adults

OBJECTIVES

Despite widespread vaccination programmes, pertussis remains a significant health burden in many countries. Low awareness of the disease, the high rate of asymptomatic cases in adults and difficulties with diagnosis could explain the under-reporting of pertussis. The lack of data on actual incidence constitutes an obstacle for public health authorities for the implementation of a vaccination strategy against pertussis in adults. The aim of this study was to evaluate the seroprevalence of antibodies against Bordetella pertussis infection in adults and to estimate the actual incidence of the disease compared with the reported incidence.

STUDY DESIGN

Prospective, multicentre seroprevalence study.

METHODS

The study was conducted in 2000 adult subjects aged ≥18 years who had not received pertussis vaccination within the last 5 years. All enrolled subjects provided a blood sample for serum testing of IgG antibodies against pertussis toxin, performed by enzyme-linked immunosorbent assay, to indicate if they had an acute infection or if they had been infected with pertussis within the last 12 months or earlier. Results were validated in accordance with the guidelines of the European Sero-epidemiology Network 2 and were expressed in ESEN units/ml.

RESULTS

A positive concentration of anti-pertussis toxin antibodies, indicating previous pertussis infection, was demonstrated in 39.9% (n = 799) of all study subjects, and 0.40% (n = 8) of subjects had a concentration suggestive of a recent infection (within the last 12 months). The highest antibody seroprevalence was observed in subjects aged 18-29 years (1.46%). No cases of acute infection were detected.

CONCLUSIONS

During the study period, the reported incidence of pertussis in the adult population was 0.84/100,000 inhabitants. Based on the seroprevalence results from this study, it is estimated that the actual incidence of pertussis could be as much as 699/100,000 inhabitants. The actual incidence of pertussis in adults in the Czech Republic could therefore be at least 200-fold higher than the reported incidence. These findings support the need for pertussis vaccination in the adult population.

Vaccination in newly arrived immigrants to the European Union

The challenge of assimilating millions of immigrants in the European region each year presents significant socioeconomic issues. Among them is the threat of vaccine preventable diseases (VPDs) disease transmission within immigrant groups and the broader population given the permeability of nation state borders. A total of 3.8 million people immigrated to the European Union (EU) in 2014, among those were 1.6 million non-EU nationals. While vaccines have markedly reduced the transmission of disease, clusters of under-vaccinated individuals potentiate the rapid transmission of once-eradicated or controlled diseases. Immigrants pose a special challenge to host country public health vaccination programmes. Wars in their native countries may have interrupted vaccination programmes, documentation may be unavailable or unreliable, and refugees may present with health issues due to poor sanitation and food during transit. Further, immigrants are often reticent to access health care in the destination country, or may face financial or language barriers. Thus, preventive health care needs may go unaddressed and the first contact with a clinician is for an emergency. Equitable access to acute and preventive health care and services, including immunizations irrespective of individual's immigration status, should be a priority for European region countries. Ensuring appropriate and timely vaccination for immigrants could be accomplished with a universal European region immunization schedule. Priority should be given to highly communicable VPDs such as measles, mumps, rubella, pertussis, diphtheria, varicella and polio.

Prevalence of hepatitis C virus in adult population in the Czech Republic - time for birth cohort screening

Chronic hepatitis C is curable disease. Low detection rate could be one of the reasons of poor treatment uptake. It is important to identify HCV prevalence and anti-hepatitis C virus (HCV) positive patients in population by effective screening strategy such as risk-based or birth cohort screening programs. There are no national population-based estimates of the HCV prevalence in the Czech Republic (CZ). The most recent seroprevalence survey determined a prevalence of positive anti-HCV antibodies of 0.2% (in 2001). The aim of the study was to determine the seroprevalence of HCV, HCV viraemia and HCV genotype in the CZ adult population. We also estimated the number of persons living with chronic hepatitis C in CZ. The examined group included 3000 adults, 18–90 years of age enrolled in 2015. All serum samples were examined to determined anti-HCV antibodies positivity, HCV-RNA positivity and genotypes. Of the 3000 samples, 50 were found to be anti-HCV-positive, for a seroprevalence of 1.67% (2.39% in males, 0.98% in females). The overall prevalence of positive HCV RNA was 0.93%: 1.5% in males, 0.39% in females. HCV genotype (GT) 1a was determined in 25%, GT 1b in 25% and GT 3a in 46%. Since 2001, the HCV seroprevalence has increased 8-fold. The highest HCV seroprevalence occurred in males aged 30–44 years. We can estimate that there are more than 140,000 people with HCV antibodies and more than 80,000 people with chronic hepatitis C living in the CZ. The introduction of birth cohort HCV screening could be beneficial for the country.

Decreasing Seroprevalence of Measles Antibodies after Vaccination - Possible Gap in Measles Protection in Adults in the Czech Republic

Aims

In recent years, Europe has recorded an increase in the number of measles outbreaks despite the implementation of vaccination into the National Immunization Programs. The Czech Republic introduced vaccination against measles into National Immunization Program in 1969. The aim of this study was to determine seroprevalence of IgG antibodies against measles in adults.

Methods

Our study was designed as a prospective, multicenter cohort study. Samples of blood were taken from adults aged 18 years and over. Specific IgG antibodies were determined by ELISA method.

Results

A number of 1911 sera samples were obtained. The total seropositivity reached 83.3%, 14.3% of the results were negative and 2.4% were borderline. When comparing the individual age groups, the highest antibody seropositivity (> 96%) was detected in persons aged 50 years and over who were naturally infected in pre-vaccine era. The lowest seropositivity was recorded in the age groups 30–39 years (61.5%), 40–49 years (77.5%) and 18–29 years (81.1%).

Conclusions

A long term high rate of seropositivity persists after natural measles infection. By contrast, it decreases over time after vaccination. Similarly, the concentrations of antibodies in persons with measles history persist for a longer time at a higher level than in vaccinated persons. Our results indicate possible gap in measles protection in adults born after implementation of vaccination into the National Immunization Programs. There are two probable reasons, decrease of measles antibody seropositivity in time after vaccination in setting of limited natural booster and one-dose vaccination schedule used in the first years after implementation.

Efficacy of the Herpes Zoster Subunit Vaccine in Adults 70 Years of Age or Older

BACKGROUND

A trial involving adults 50 years of age or older (ZOE-50) showed that the herpes zoster subunit vaccine (HZ/su) containing recombinant varicella-zoster virus glycoprotein E and the AS01B adjuvant system was associated with a risk of herpes zoster that was 97.2% lower than that associated with placebo. A second trial was performed concurrently at the same sites and examined the safety and efficacy of HZ/su in adults 70 years of age or older (ZOE-70).

METHODS

This randomized, placebo-controlled, phase 3 trial was conducted in 18 countries and involved adults 70 years of age or older. Participants received two doses of HZ/su or placebo (assigned in a 1:1 ratio) administered intramuscularly 2 months apart. Vaccine efficacy against herpes zoster and postherpetic neuralgia was assessed in participants from ZOE-70 and in participants pooled from ZOE-70 and ZOE-50.

RESULTS

In ZOE-70, 13,900 participants who could be evaluated (mean age, 75.6 years) received either HZ/su (6950 participants) or placebo (6950 participants). During a mean follow-up period of 3.7 years, herpes zoster occurred in 23 HZ/su recipients and in 223 placebo recipients (0.9 vs. 9.2 per 1000 person-years). Vaccine efficacy against herpes zoster was 89.8% (95% confidence interval [CI], 84.2 to 93.7; P<0.001) and was similar in participants 70 to 79 years of age (90.0%) and participants 80 years of age or older (89.1%). In pooled analyses of data from participants 70 years of age or older in ZOE-50 and ZOE-70 (16,596 participants), vaccine efficacy against herpes zoster was 91.3% (95% CI, 86.8 to 94.5; P<0.001), and vaccine efficacy against postherpetic neuralgia was 88.8% (95% CI, 68.7 to 97.1; P<0.001). Solicited reports of injection-site and systemic reactions within 7 days after injection were more frequent among HZ/su recipients than among placebo recipients (79.0% vs. 29.5%). Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two study groups.

CONCLUSIONS

In our trial, HZ/su was found to reduce the risks of herpes zoster and postherpetic neuralgia among adults 70 years of age or older. (Funded by GlaxoSmithKline Biologicals; ZOE-50 and ZOE-70 ClinicalTrials.gov numbers, NCT01165177 and NCT01165229 .).

Comparative Epidemiologic Characteristics of Pertussis in 10 Central and Eastern European Countries, 2000-2013

We undertook an epidemiological survey of the annual incidence of pertussis reported from 2000 to 2013 in ten Central and Eastern European countries to ascertain whether increased pertussis reports in some countries share common underlying drivers or whether there are specific features in each country. The annual incidence of pertussis in the participating countries was obtained from relevant government institutions and/or national surveillance systems. We reviewed the changes in the pertussis incidence rates in each country to explore differences and/or similarities between countries in relation to pertussis surveillance; case definitions for detection and confirmation of pertussis; incidence and number of cases of pertussis by year, overall and by age group; population by year, overall and by age group; pertussis immunization schedule and coverage, and switch from whole-cell pertussis vaccines (wP) to acellular pertussis vaccines (aP). There was heterogeneity in the reported annual incidence rates and trends observed across countries. Reported pertussis incidence rates varied considerably, ranging from 0.01 to 96 per 100,000 population, with the highest rates generally reported in Estonia and the lowest in Hungary and Serbia. The greatest burden appears for the most part in infants (<1 year) in Bulgaria, Hungary, Latvia, Romania, and Serbia, but not in the other participating countries where the burden may have shifted to older children, though surveillance of adults may be inappropriate. There was no consistent pattern associated with the switch from wP to aP vaccines on reported pertussis incidence rates. The heterogeneity in reported data may be related to a number of factors including surveillance system characteristics or capabilities, different case definitions, type of pertussis confirmation tests used, public awareness of the disease, as well as real differences in the magnitude of the disease, or a combination of these factors. Our study highlights the need to standardize pertussis detection and confirmation in surveillance programs across Europe, complemented with carefully-designed seroprevalence studies using the same protocols and methodologies.

Long-term immunogenicity and safety of an investigational herpes zoster subunit vaccine in older adults

BACKGROUND

An investigational subunit vaccine containing the varicella-zoster virus (VZV) glycoprotein E (gE) and the AS01B adjuvant system is being evaluated for the prevention of herpes zoster (HZ) in older adults. A phase II trial evaluating different formulations of this vaccine (containing 25μg, 50μg, or 100μg gE) was conducted in adults ≥60 years of age and showed that all formulations elicited robust cellular and humoral immune responses for up to 3 years after vaccination. In this follow-up study in subjects who received two doses of the 50μg gE/AS01B formulation (HZ/su), we assessed the persistence of the immune responses for up to 6 years after vaccination.

METHODS

This phase II, open-label, multicenter, single-group trial conducted in the Czech Republic, Germany, Sweden, and the Netherlands followed 129 subjects who had received two doses (2 months apart) of HZ/su during the initial trial. Vaccine-induced immune responses (frequencies of gE-specific CD4(+) T cells expressing ≥2 activation markers and serum anti-gE antibody concentrations) were evaluated at 48, 60, and 72 months after the first HZ/su dose.

RESULTS

Six years after vaccination with HZ/su, gE-specific cell-mediated immune responses and anti-gE antibody concentrations had decreased by 20-25% from month 36, but remained higher than the prevaccination values. At month 72, the gE-specific cell-mediated immune response was 3.8 times higher than the prevaccination value (477.3 vs. 119.4 activated gE-specific CD4(+) T cells per 10(6) cells), and the anti-gE antibody concentration was 7.3 times higher than the prevaccination value (8159.0 vs. 1121.3mIU/mL). No vaccine-related serious adverse events were reported between months 36 and 72.

CONCLUSIONS

gE-specific cellular and humoral immune responses persisted for 6 years after two-dose vaccination with HZ/su in healthy older adults. No safety concerns were identified.

Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults

BACKGROUND

In previous phase 1-2 clinical trials involving older adults, a subunit vaccine containing varicella-zoster virus glycoprotein E and the AS01B adjuvant system (called HZ/su) had a clinically acceptable safety profile and elicited a robust immune response.

METHODS

We conducted a randomized, placebo-controlled, phase 3 study in 18 countries to evaluate the efficacy and safety of HZ/su in older adults (≥50 years of age), stratified according to age group (50 to 59, 60 to 69, and ≥70 years). Participants received two intramuscular doses of the vaccine or placebo 2 months apart. The primary objective was to assess the efficacy of the vaccine, as compared with placebo, in reducing the risk of herpes zoster in older adults.

RESULTS

A total of 15,411 participants who could be evaluated received either the vaccine (7698 participants) or placebo (7713 participants). During a mean follow-up of 3.2 years, herpes zoster was confirmed in 6 participants in the vaccine group and in 210 participants in the placebo group (incidence rate, 0.3 vs. 9.1 per 1000 person-years) in the modified vaccinated cohort. Overall vaccine efficacy against herpes zoster was 97.2% (95% confidence interval [CI], 93.7 to 99.0; P<0.001). Vaccine efficacy was between 96.6% and 97.9% for all age groups. Solicited reports of injection-site and systemic reactions within 7 days after vaccination were more frequent in the vaccine group. There were solicited or unsolicited reports of grade 3 symptoms in 17.0% of vaccine recipients and 3.2% of placebo recipients. The proportions of participants who had serious adverse events or potential immune-mediated diseases or who died were similar in the two groups.

CONCLUSIONS

The HZ/su vaccine significantly reduced the risk of herpes zoster in adults who were 50 years of age or older. Vaccine efficacy in adults who were 70 years of age or older was similar to that in the other two age groups. (Funded by GlaxoSmithKline Biologicals; ZOE-50 ClinicalTrials.gov number, NCT01165177.).

Safety and immunogenicity of three different formulations of an adjuvanted varicella-zoster virus subunit candidate vaccine in older adults: a phase II, randomized, controlled study

BACKGROUND

This study investigated the safety and immunogenicity of different formulations and schedules of a candidate subunit herpes zoster vaccine containing varicella-zoster virus glycoprotein E (gE) with or without the adjuvant system AS01B.

METHODS

In this phase II, single-blind, randomized, controlled study, adults aged ≥60years (N=714) received one dose of 100μggE/AS01B, two doses, two months apart, of 25, 50, or 100μggE/AS01B, or two doses of unadjuvanted 100μggE/saline. Frequencies of CD4(+) T cells expressing ≥2 activation markers following induction with gE were measured by intracellular cytokine staining and serum anti-gE antibody concentrations by ELISA.

RESULTS

Frequencies of gE-specific CD4(+) T cells were >3-fold higher after two doses of all gE/AS01B formulations than after one dose of 100μggE/AS01B or two doses of 100μggE/saline. Frequencies were comparable after two doses of 25, 50, or 100μggE/AS01B. Serum anti-gE antibody concentrations were comparable after two doses of 50 or 100μggE/AS01B and higher than in the other groups. Immune responses persisted for at least 36 months. Reactogenicities of all gE/AS01B formulations were similar but greater than with gE/saline.

CONCLUSIONS

The three formulations of gE/AS01B were immunogenic and well tolerated in adults aged ≥60years. Two vaccinations with gE/AS01B induced higher immune responses than one and the dose of gE impacted humoral but not cellular immune responses (NCT00434577).

Safety and immunogenicity of an AS01-adjuvanted varicella-zoster virus subunit candidate vaccine against herpes zoster in adults >=50 years of age

BACKGROUND

An adjuvanted varicella-zoster virus glycoprotein E (gE) subunit vaccine candidate for herpes zoster is in development. In this trial we compared the safety, reactogenicity, and immunogenicity of the vaccine antigen combined with different adjuvant doses.

METHODS

This was a phase II, observer-blind, randomized, multinational study. Adults ≥50 years old were randomized 4:4:2:1 to be vaccinated at months 0 and 2 with gE combined with a higher (AS01B) or lower (AS01E) dose adjuvant, unadjuvanted gE, or saline. Following each dose, solicited events were recorded for 7 days and unsolicited adverse events for 30 days. Serious adverse events were collected for 1 year. Cell-mediated and humoral immune responses were assessed at baseline and following each dose.

RESULTS

No vaccine-related severe adverse events were reported. Solicited adverse events were generally mild to moderate and transient. For all gE-based vaccines, pain was the most common local symptom and fatigue the most common general symptom. Immune responses were significantly enhanced by AS01B and AS01E compared to unadjuvanted gE and were significantly stronger for gE/AS01B than for gE/AS01E.

CONCLUSIONS

AS01 improved the immunogenicity of gE while retaining acceptable safety and reactogenicity profiles. The enhancement of gE-specific cellular and humoral responses was adjuvant dose dependent.

CLINICAL TRIALS REGISTRATION

NCT00802464.

Rotavirus vaccination in central Europe

Each year, rotavirus (RV) infection is the leading cause of acute gastroenteritis requiring hospitalisation and of nosocomially transmitted diseases in children younger than 5 years across Central European Vaccination Awareness Group (CEVAG) countries; however, inadequate surveillance systems and lack of routine RV testing still exist in most CEVAG countries, making it difficult to accurately assess the present burden of acute RV gastroenteritis in the younger population. Furthermore, routine immunisation of infants with RV vaccines has not been implemented, and no official and uniform recommendations exist in most of the countries in these territories. The present study provides CEVAG country-specific estimates of the disease burden of RV gastroenteritis among the youngest population and presents evidence-based advice on the use of RV vaccines in the region, while providing a framework for vaccination at the national level.

Recommendations for tick-borne encephalitis vaccination from the Central European Vaccination Awareness Group (CEVAG)

Tick-borne encephalitis (TBE) is a viral neurological zoonotic disease transmitted to humans by ticks or by consumption of unpasteurized dairy products from infected cows, goats, or sheep. TBE is highly endemic in areas of Central and Eastern Europe and Russia where it is a major public health concern. However, it is difficult to diagnose TBE as clinical manifestations tend to be relatively nonspecific and a standardized case definition does not exist across the region. TBE is becoming more important in Europe due to the appearance of new endemic areas. Few Central European Vaccination Awareness Group (CEVAG) member countries have implemented universal vaccination programmes against TBE and vaccination coverage is not considered sufficient to control the disease. When implemented, immunization strategies only apply to risk groups under certain conditions, with no harmonized recommendations available to date across the region. Effective vaccination programmes are essential in preventing the burden of TBE. This review examines the current situation of TBE in CEVAG countries and contains recommendations for the vaccination of children and high-risk groups. For countries at very high risk of TBE infections, CEVAG strongly recommends the introduction of universal TBE vaccination in children > 1 y of age onwards. For countries with a very low risk of TBE, recommendations should only apply to those traveling to endemic areas. Overall, it is generally accepted that each country should be free to make its own decision based on regional epidemiological data and the vaccination calendar, although recommendations should be made, especially for those living in endemic areas.

Opportunity for healthy ageing: lessening the burden of adult pneumococcal disease in Central and Eastern Europe, and Israel

The population of the Region (Central Europe, Eastern Europe, and Israel) is ageing, necessitating preventative programmes to maintain a healthy and active lifestyle in older age groups. Invasive pneumococcal disease (including bacteremic pneumonia, bacteremia without a focus, and meningitis) has higher incidence, morbidity and mortality in older adults and is a substantial public health burden in the ageing population. Surveillance in the Region establishes a significant burden in older adults of invasive pneumococcal disease (IPD), which still appears to be under-estimated as compared with other countries, and this warrants an improvement in surveillance systems. The largest proportion of IPD in adults is bacteremic pneumonia. Community-acquired pneumonia (CAP), largely attributable to S. pneumoniae, can be bacteremic or non-bacteremic; the non-bacteremic forms of CAP also represent a significant burden in the Region. The burden of pneumococcal disease can be reduced with programmes of effective vaccination. Recommendations on pneumococcal vaccination in adults vary widely across the Region. The main barrier to implementation of vaccination programmes is low awareness among healthcare professionals on serious heatlh consequences of adult pneumococcal disease and of vaccination options. The Expert Panel calls on healthcare providers in the Region to improve pneumococcal surveillance, optimize and disseminate recommendations for adult vaccination, and support awareness and education programmes about adult pneumococcal disease.

Genotyping of varicella-zoster virus (vzv) wild-type strains isolated in the Czech Republic

OBJECTIVES

Monitoring of the varicella-zoster virus is becoming an important tool for analysis of the circulation of individual strains of VZV which differ not only at the genomic level, but show a variability in their clinical and epidemiological characteristics. Such data are not available on a large scale from the Czech population and could help understanding the epidemiological and evolutionary characteristics of the virus, as well as its potential for reinfection and increased pathogenesis in the population groups at higher risk for complications. The main aim of this study was detection and monitoring of wild-type or vaccine VZV strain isolates in the region of Eastern Bohemia and genotypic characterization of these isolates.

MATERIAL

A total of 273 clinical samples were obtained from patients exhibiting symptoms of varicella zoster virus (VZV) infection manifested as chickenpox or herpes zoster (HZ) treated in the Faculty Hospital of Charles University, Medical School in Hradec Kralove, Czech Republic.

METHODS

Characterization of individual short VZV DNA sequences was performed utilizing restriction fragment length polymorphisms (RFLPs), PCR and sequencing. Single nucleotide polymorphisms (SNP) in open reading frames (ORF) 21, 22 and 50 were used to identify individual VZV strains.

RESULTS

All clinical isolates (97 from varicella, 176 from herpes zoster) were VZV positive wild-type strains. Sequencing analysis showed that 89 isolates were of the European E1 genotype, 180 were of the European E2 genotype and 2 were identified as the Mosaic M1 strain. In addition, for the first time in this region two unusual genotypes were identified, both representing a combination of E1 and M2 strain specific SNPs.

CONCLUSION

Our prospective VZV genotyping study which is the first to monitor the VZV epidemiological situation in the Czech Republic using such a large set of clinical specimens, has provided valuable epidemiological data and identified two unique VZV recombinants.

An unusual case of multi-recurrent herpes zoster (Hz): a case report

AIMS

We report a case of multi-recurrent herpes zoster in a 53-year-old Caucasian woman treated repeatedly at the Faculty Hospital Hradec Kralove, Czech Republic over the years 2009 - 2011.

METHODS

Specific PCR methods targeting single nucleotide polymorphisms (SNPs) in open reading frames (ORF) 38, 54 and 62 were utilized to determine vaccine or wild type varicella-zoster (VZV) strains followed by SNPs analysis using two amplicons in ORF 22 and/or ORF 21/ORF 50. Additional genotyping in ORF 1, 6, 9 and 28 was subsequently performed due to the unusual results.

RESULTS

Three sets of clinical specimens from one patient (from hospital visits 2, 3 and 4) were analyzed and the presence of an unusual wild-type strain of VZV was discovered. The VZV strain isolated from the lesions bears a combination of markers characteristic both for Mosaic 2 (M2) and European 1 (E1) wild-type VZV strains.

CONCLUSION

This is the first report of atypical wild-type VZV strain circulating currently in Czech Republic.

Rubella revisited: where are we on the road to disease elimination in Central Europe?

Rubella is a contagious viral disease with few complications except when contracted by pregnant women. Rubella infection in pregnancy can result in miscarriage, stillbirth or an infant born with congenital rubella syndrome (CRS) which comprises deafness, heart disease, cataracts and other permanent congenital manifestations. Clinical diagnosis of rubella is difficult due to overlapping symptoms with many other diseases and confirmation of rubella is not possible without laboratory testing. Effective vaccination programmes are critical to the elimination of rubella and prevention of CRS. Such programmes have been successful in several countries in Europe and around the world. However, rubella outbreaks still occur due to suboptimal vaccine coverage and in the past 10 years rubella has been reported in Central European countries such as Romania and Poland. Over the past decade the elimination of rubella and prevention of congenital rubella infection in Europe has been a high priority for the WHO European Regional Office. In 2010 the WHO regional committee for Europe renewed its commitment to the elimination of rubella and prevention of CRS with a new target of 2015. This paper examines the current situation for rubella and CRS in Central Europe and describes the different rubella vaccination programmes in the region. The Central European Vaccination Advisory Group (CEVAG) recommends that two doses of measles, mumps and rubella vaccine, MMR, should be given to all children. The first dose should be given between 12 and 15 months of age. The second dose can be given between the ages of 21 months and 13 years with the exact age of administration of the second dose depending on the situation specific to each country. All suspected rubella cases should be laboratory-confirmed and monitoring systems to detect and investigate cases of CRS should be strengthened.

[Vaccination against viral hepatitis A and B in adults aged over 40 years--antibody persistence and immune memory]

STUDY OBJECTIVE

Primary vaccination with combined vaccine against viral hepatitis A (VHA) and viral hepatitis B (VHB) induces higher anti-hepatitis B surface (anti-HBs) antibody responses and similar anti-hepatitis A virus (anti-HAV) antibody responses in adults aged over 40 years in comparison with concomitant monovalent vaccines against VHA and VHB. Th e objectives were to assess, in a clinical study, persistence of anti-HAV and anti-HBs antibodies in adults aged over 40 years four years after primary VHA/VHB vaccination and antibody response following a booster dose of the vaccine.

MATERIAL AND METHODS

Five hundred and ninety-six subjects aged > 40 years were vaccinated with three doses of the combined VHA/VHB vaccine at Months 0, 1, 6 (HAB group) or with concomitant VHA and VHB vaccines at Months 0, 6 and 0, 1, 6 (ENG+HAV and HBVX+VAQ, respectively). Blood samples were collected one month following primary vaccination (Month 7) and then at one-year intervals for four years after the booster dose with the same vaccine as used for the primary vaccination. The anti-HBs and anti-HAV antibody levels were determined prior to the booster dose and at days 14 and 30 after the booster dose.

RESULTS

At Month 7, > 97% of study subjects were seropositive for anti-HAV antibodies in all groups analyzed. Four years after primary vaccination, anti-HAV antibody seropositivity persisted in > 93% of study subjects, increasing to > 99% after the booster dose. At Month 7, the highest proportion of study subjects with anti-HBs antibody levels > or = 10 mIU/ml was found in the HAB group (91.7% versus 79.7% in the ENG+HAV group versus 71.0% in the HBVX+VAQ group). Four years after vaccination, anti-HBs antibody levels of 10 mIU/ml persisted in 57.1% of the HAB study subjects in comparison with 40.1% and 26.6% of the study subjects in the ENG+HAV and HBVX+VAQ groups, respectively. One month after the booster dose, anti-HBs antibody levels increased and antibody levels > or = 10 mIU/ml was achived in 95.2% of study subjects in the HAB group, 90.5% in the ENG+HAV group and 85.3% in the HBVX+VAQ group.

CONCLUSION

In the adults aged over 40 years, an adequate anti-HAV antibody response persisted for at least four years after vaccination and was higher and more sustained in those who received the combined HAB vaccine. A strong antibody response to the booster dose indicative ofthe presence of immune memory was seen in all study groups.

Antibody persistence and immune memory 4 years post-vaccination with combined hepatitis A and B vaccine in adults aged over 40 years

Persistence of immune response was assessed in adults aged >40 years (N = 596) following primary vaccination with combined hepatitis A/B vaccine or concomitant monovalent hepatitis A and B vaccines. Anti-hepatitis A virus antibody responses persisted for at least 4 years regardless of the vaccine used, with anti-hepatitis B surface antibody responses higher and more sustained in subjects who received the combined hepatitis A/B vaccine. Response rates to an additional dose of the same vaccine(s) used for priming were high.

Central European Vaccination Advisory Group (CEVAG) guidance statement on recommendations for influenza vaccination in children

Background

Influenza vaccination in infants and children with existing health complications is current practice in many countries, but healthy children are also susceptible to influenza, sometimes with complications. The under-recognised burden of disease in young children is greater than in elderly populations and the number of paediatric influenza cases reported does not reflect the actual frequency of influenza.

Discussion

Vaccination of healthy children is not widespread in Europe despite clear demonstration of the benefits of vaccination in reducing the large health and economic burden of influenza. Universal vaccination of infants and children also provides indirect protection in other high-risk groups in the community. This paper contains the Central European Vaccination Advisory Group (CEVAG) guidance statement on recommendations for the vaccination of infants and children against influenza. The aim of CEVAG is to encourage the efficient and safe use of vaccines to prevent and control infectious diseases.

Summary

CEVAG recommends the introduction of universal influenza vaccination for all children from the age of 6 months. Special attention is needed for children up to 60 months of age as they are at greatest risk. Individual countries should decide on how best to implement this recommendation based on their circumstances.

Effect of prophylactic paracetamol administration at time of vaccination on febrile reactions and antibody responses in children: two open-label, randomised controlled trials

BACKGROUND

Although fever is part of the normal inflammatory process after immunisation, prophylactic antipyretic drugs are sometimes recommended to allay concerns of high fever and febrile convulsion. We assessed the effect of prophylactic administration of paracetamol at vaccination on infant febrile reaction rates and vaccine responses.

METHODS

In two consecutive (primary and booster) randomised, controlled, open-label vaccination studies, 459 healthy infants were enrolled from ten centres in the Czech Republic. Infants were randomly assigned with a computer-generated randomisation list to receive three prophylactic paracetamol doses every 6-8 h in the first 24 h (n=226) or no prophylactic paracetamol (n=233) after each vaccination with a ten-valent pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) co-administered with the hexavalent diphtheria-tetanus-3-component acellular pertussis-hepatitis B-inactivated poliovirus types 1, 2, and 3-H influenzae type b (DTPa-HBV-IPV/Hib) and oral human rotavirus vaccines. The primary objective in both studies was the reduction in febrile reactions of 38.0 degrees C or greater in the total vaccinated cohort. The second objective was assessment of immunogenicity in the according-to-protocol cohort. These studies are registered with ClinicalTrials.gov, numbers NCT00370318 and NCT00496015.

FINDINGS

Fever greater than 39.5 degrees C was uncommon in both groups (after primary: one of 226 participants [<1%] in prophylactic paracetamol group vs three of 233 [1%] in no prophylactic paracetamol group; after booster: three of 178 [2%] vs two of 172 [1%]). The percentage of children with temperature of 38 degrees C or greater after at least one dose was significantly lower in the prophylactic paracetamol group (94/226 [42%] after primary vaccination and 64/178 [36%] after booster vaccination) than in the no prophylactic paracetamol group (154/233 [66%] after primary vaccination and 100/172 [58%] after booster vaccination). Antibody geometric mean concentrations (GMCs) were significantly lower in the prophylactic paracetamol group than in the no prophylactic paracetamol group after primary vaccination for all ten pneumococcal vaccine serotypes, protein D, antipolyribosyl-ribitol phosphate, antidiphtheria, antitetanus, and antipertactin. After boosting, lower antibody GMCs persisted in the prophylactic paracetamol group for antitetanus, protein D, and all pneumococcal serotypes apart from 19F.

INTERPRETATION

Although febrile reactions significantly decreased, prophylactic administration of antipyretic drugs at the time of vaccination should not be routinely recommended since antibody responses to several vaccine antigens were reduced.

FUNDING

GlaxoSmithKline Biologicals (Belgium).

Hepatitis A/B vaccination of adults over 40 years old: Comparison of three vaccine regimens and effect of influencing factors

Challenged by contrasting data on low immune responses in the elderly with a combined hepatitis A/B vaccine, a randomised, controlled study was conducted to assess the immunogenicity of three hepatitis A and B vaccination regimens (group 1: combined hepatitis A/B vaccine Twinrix [GSK]; group 2: co-administered hepatitis A vaccine, Havrix [GSK]+hepatitis B vaccine Engerix -B [GSK], group 3: co-administered hepatitis A vaccine, Vaqta [Sanofi-Pasteur MSD]+hepatitis B vaccine HB VAX PRO [Sanofi-Pasteur MSD]) and the effect of influencing factors in subjects >40 years. On completion of the full vaccination course, anti-HBs seroprotection (SP) rates were 92, 80 and 71% in groups 1, 2 and 3, respectively; anti-HAV seropositivity (S+) rates were 97, 99 and 99%, respectively. In group 1, anti-HBs SP rate was non-inferior as well as superior and anti-HAV S+ rate was non-inferior to that in groups 2 and 3. Anti-HBs response was most significantly influenced by the vaccine regimen, followed by age, gender and BMI (stepwise multiple regression analysis). BMI had the most significant influence on HAV response followed by age, gender and vaccine regimen. In conclusion, Twinrix induced superior hepatitis B SP rates and similar hepatitis A S+ rates compared to concomitant administration of monovalent vaccines in subjects aged >40 years.

Anthrax vaccines

Anthrax, an uncommon disease in humans, is caused by a large bacterium, Bacillus anthracis. The risk of inhalation infection is the main indication for anthrax vaccination. Pre-exposure vaccination is provided by an acellular vaccine (anthrax vaccine adsorbed or AVA), which contains anthrax toxin elements and results in protective immunity after 3 to 6 doses. Anthrax vaccine precipitated (AVP) is administered at primovaccination in 3 doses with a booster dose after 6 months. To evoke and maintain protective immunity, it is necessary to administer a booster dose once at 12 months. In Russia, live spore vaccine (STI) has been used in a two-dose schedule. Current anthrax vaccines show considerable local and general reactogenicity (erythema, induration, soreness, fever). Serious adverse reactions occur in about 1% of vaccinations. New second-generation vaccines in current research programs include recombinant live vaccines and recombinant sub-unit vaccines.

A combined dual-chamber typhoid/hepatitis A vaccine as a booster dose in hepatitis A primed adults

Vivaxim is a combined hepatitis A/typhoid fever vaccine (HA/Vi) licensed for vaccination of travellers, but long-term protection against hepatitis A requires two immunisations at least 6 months apart. A randomised, controlled study was performed in 116 healthy adults primed with hepatitis A vaccine (Avaxim) to compare immune responses to HA/Vi and Avaxim given as booster doses 6 months later. Both vaccines elicited marked booster responses achieving antibody geometric mean titres (GMTs) of 4576 and 3760 mIU/ml in the HA/Vi and Avaxim groups, respectively. Although twice as frequent in the HA/Vi group, local reactions (mostly pain) were mainly mild and transient, probably reflecting the larger volume injected (1ml). Vivaxim offers a convenient means of administering both HA and typhoid fever vaccines in subjects already primed for hepatitis A.