Ralf Clemens

Immunogenicity and tolerability of a multicomponent meningococcal serogroup B (4CMenB) vaccine in healthy adolescents in Chile: a phase 2b/3 randomised, observer-blind, placebo-controlled study

BACKGROUND Effective glycoconjugate vaccines against Neisseria meningitidis serogroups A, C, W-135, and Y have been developed, but serogroup B remains a major cause of severe invasive disease in infants and adolescents worldwide. We assessed immunogenicity and tolerability of a four-component vaccine (4CMenB) in adolescents. METHODS We did a randomised, observer-blind, placebo-controlled, study at 12 sites in Santiago and Valparaíso, Chile. Adolescents aged 11-17 years received one, two, or three doses of 4CMenB at 1 month, 2 month, or 6 month intervals. Immunogenicity was assessed as serum bactericidal activity using human complement (hSBA) against three reference strains for individual vaccine antigens, and assessed by ELISA against the fourth strain. Local and systemic reactions were recorded 7 days after each vaccination, and adverse events were monitored throughout the study. Participants were initially randomised to five groups (3:3:3:3:1) during the primary phase to receive either one dose, two doses 1 or 2 months apart, or three doses of 4CMenB, or three doses of placebo, with an additional three groups generated for the booster phase. All subjects received at least one dose of 4CMenB. Geometric mean titres, proportions of participants with serum bactericidal antibody titres of 4 or more, and Clopper-Pearson 95% CIs were calculated. The study is registered with ClinicalTrials.gov, number NCT00661713. FINDINGS Overall, 1631 adolescents (mean age 13·8 [SD 1·9] years) received at least one dose of 4CMenB. After two or three doses, 99-100% of recipients had hSBA titres of 4 or more against test strains, compared with 92-97% after one dose (p<0·0145) and 29-50% after placebo. At 6 months 91-100% of participants still had titres of 4 or more for each strain after two or three doses, but only 73-76% after one dose; seroresponse rates reached 99-100% for each strain after second or third doses at 6 months. Local and systemic reaction rates were similar after each 4CMenB injection and did not increase with subsequent doses, but remained higher than placebo. No vaccine-related serious adverse events were reported and no significant safety signals were identified. INTERPRETATION On the basis of immunogenicity responses this study provides evidence for an adolescent 4CMenB vaccine schedule of two doses, 1-6 months apart, to provide protection against meningococcal B infection. The extent of this protection against meningococcus B variants circulating worldwide will be determined by national surveys. FUNDING Novartis Vaccines and Diagnostics.

Soroprevalência para hepatite A e hepatite B em quatro centros no Brasil

The prevalence of antibodies to hepatitis A and B virus was assessed in 3,653 subjects across four regions of Brazil. The anti-HAV and anti-HBc seroprevalence were 64.7% and 7.9%, respectively. The highest anti-HAV (92.8%) and anti-HBc (21.4%) rates were seen in the Northern region. In other regions, anti-HAV seroprevalence over 90% was only reached in the more elderly, indicating an intermediate endemicity and a significantly higher anti-HAV prevalence was seen in the low socioeconomic group between 1-30 years. With respect to anti-HBc seroprevalence an increase was seen in adolescents and there was a significantly higher anti-HBc prevalence in the lower socioeconomic group between 1-20 years. A 3.1% anti-HBc prevalence was seen in one-year-old infants, suggesting a vertical transmission. The major findings of this study indicate that the pre-adolescent and adolescent population in some Brazilian cities are at greatest risk from both hepatitis A and B infection, but for different reasons.

Explorations of clinical trials and pharmacovigilance databases of MF59®-adjuvanted influenza vaccines for associated cases of narcolepsy

Abstract Background: A potential association between the new onset of narcolepsy accompanied by cataplexy – a putative autoimmune disorder, and vaccination with an AS03-adjuvanted A(H1N1) pandemic influenza vaccine is under investigation. We sought cases of narcolepsy from the pharmacovigilance database of a pandemic vaccine adjuvanted with another emulsion adjuvant, MF59®, and a pooled clinical trials database of MF59-adjuvanted and non-adjuvanted influenza vaccine recipients. Methods: Using 6 narrowly restrictive and 24 broad sleep disturbance-related MedDRA preferred search terms (PT), we analysed spontaneous adverse events (AEs) reports received through July 31, 2010 and adjudicated suspected cases with onset 1 week–3 months after vaccination, against standardized clinical criteria defining narcolepsy. A pooled clinical trials database of 115 trials comprising 79,004 subjects receiving various MF59-adjuvanted and non-adjuvanted influenza vaccines in controlled and uncontrolled trials was analysed for cases with a narrow PT that had onset 1 week after vaccination. Results: Five thousand three hundred and five spontaneous AE reports were received from an estimated 23.26 million MF59-adjuvanted pandemic vaccine doses that had been administered. No case meeting the clinical definition of narcolepsy was discovered. In the pooled database of controlled clinical trials, no cases were discovered using the narrow PT, and rates and adjusted odds ratio for broad search terms for all temporal windows showed no significant difference between subjects receiving MF59-adjuvanted or non-adjuvanted vaccine. Conclusions: No case of narcolepsy and no evidence of an increased risk of sleep-related AEs were discovered in recipients of MF59-adjuvanted A(H1N1) pandemic and other MF59-adjuvanted influenza vaccine.

Reactogenicity and immunogenicity of a new live attenuated combined measles, mumps and rubella vaccine in healthy children

OBJECTIVE To compare the reactogenicity and immunogenicity of a novel live attenuated measles-mumps-rubella vaccine, SB MMR (Priorix; SmithKline Beecham Biologicals), with a widely used MMR vaccine, Merck MMR (M-M-R II; Merck & Co. Inc). METHODS A total of 4702 healthy children, ages 9 to 24 months, were enrolled in 8 single blind, randomized, controlled trials. Reactogenicity (local and general solicited symptoms and all unsolicited symptoms) was assessed for up to 42 days postvaccination. Immunogenicity [seroconversion rates and geometric mean titers (GMT)] was assessed at 42 or 60 days postvaccination in 1912 subjects in 7 studies. In two studies the persistence of the antibodies at Month 12 postvaccination was assessed in 201 subjects. RESULTS Local symptoms (pain on or immediately after injection; pain, redness and swelling within 4 days of injection) were reported less frequently after SB MMR than Merck MMR (P < 0.0001). General symptoms and all other events were similar between the two groups. Fever >39.5 degrees C was reported after 9.5 and 11.9% of the SB MMR and Merck MMR doses, respectively. At Days 42 to 60 postvaccination seroconversion rates for antimeasles antibodies were higher with SB MMR than with Merck MMR (98.7% vs. 96.9%, P < 0.031) but similar in both groups for anti-mumps and anti-rubella antibodies, GMTs being approximately 10% higher (P < 0.05) with Merck MMR than with SB MMR. At the Month 12 assessment the seropositivity rates and GMTs were similar in both groups. CONCLUSION When administered as primary vaccination in children in the second year of life, the new SB MMR vaccine has been shown to be superior to a comparator vaccine in terms of local reactogenicity, with equivalent immunogenicity.

Haemophilus influenzae type b disease: impact and effectiveness of diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b combination vaccines.

BACKGROUND Since 1996 in Germany primary infant immunization against Haemophilus influenzae has been most commonly given in the form of diphtheria-tetanus toxoids-acellular pertussis/H. influenzae type b (DTaP/Hib) or diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b (DTaP-IPV/Hib) combination vaccines. These combination vaccines elicit lower anti-Hib antibody concentrations than the equivalent Hib conjugate administered as a separate injection, but the clinical relevance of this phenomenon is unknown. METHODS AND FINDINGS To assess the impact of DTaP/Hib combination vaccines on the incidence of invasive Hib disease in Germany, two independent surveillance systems, one hospital- and one laboratory-based, were used during 1998 and 1999 for detection of cases. Vaccination histories of all cases detected were obtained by telephone contact with parents or health care providers. During the 2-year study period invasive H. influenzae disease in the <5-year age group continued to fall, with a mean annual incidence of 1.01/100 000 children. National vaccination coverage rates revealed that only 70% of children given DTaP/Hib or DTaP-IPV/Hib received the recommended three doses in their first year of life, but the overall effectiveness of these vaccines was high at 97.5% (95% confidence interval, 96.3 to 98.4) for those who had received at least one dose. In subjects who received the full 3-dose schedule, effectiveness was 98.8% (95% confidence interval, 98.2 to 99.3). CONCLUSION Although it is well-documented that DTaP/Hib vaccines elicit lower anti-Hib titers than separate vaccines, such combinations are effective in reducing the incidence of invasive H. influenzae type b disease.

Immunogenicity and Safety of MF59-Adjuvanted H5N1 Influenza Vaccine From Infancy to Adolescence

OBJECTIVE: This study evaluated the immunogenicity, safety, and tolerability of a MF59-adjuvanted H5N1 vaccine in a population 6 months through 17 years of age. METHODS: Healthy subjects 6 to <36 months, 3 to <9 months, and 9 to <18 years of age were assigned randomly to receive 2 doses of either a MF59-adjuvanted H5N1 vaccine (7.5 μg/dose) or a MF59-adjuvanted trivalent seasonal influenza control vaccine (15 μg/dose for each antigen). Immunogenicity against the A/Vietnam/1194/2004-like vaccine strain was measured before and 3 weeks after the 2-dose primary series, through hemagglutination inhibition (HI), single radial hemolysis (SRH), and microneutralization. Local and systemic reactions were recorded. RESULTS: A total of 335 subjects received the H5N1 vaccine, and 137 subjects received the seasonal vaccine. Rates of seroprotection (HI titer of ≥40) against the H5N1 vaccine antigen were 97% for children 6 to 36 months and 3 to 9 years of age and 89% for older children. All subjects seroconverted in the SRH assay. Microneutralization titers of ≥40 were achieved by 99% of subjects, and ≥98% of subjects, respectively. Local reactions, particularly injection site pain in older children, were common, generally mild to moderate in nature, and transient and resolved spontaneously. Up to 5% of participants. There were no vaccine-related serious adverse events in either group. CONCLUSIONS: In this pediatric population, MF59-adjuvanted H5N1 vaccine was highly immunogenic, had a good safety profile, reactogenicity comparable with that of an adjuvanted seasonal influenza control vaccine.

Hepatitis A as an etiologic agent of acute liver failure in Latin America.

Background: This prospective, multicenter study examined the importance of hepatitis viruses as etiological agents of acute liver failure (ALF) and the outcome of ALF cases in Latin American children and adolescents. Methods: The study was conducted for minimum 12 months in 9 centers in Argentina, Brazil, Chile, Colombia, Costa Rica, and Mexico during 2001–2002. Hospitalized patients aged 1–20 years with a suspected diagnosis of ALF were included in the study and tested for serologic markers for hepatitis A, B, and C viruses. Results: Of the 106 patients enrolled, 88 were included in the analysis. Median age was 5 years, and 55% with ALF were aged 1–5 years. A total of 37 individuals (43%) tested positive for anti-hepatitis A virus (HAV) immunoglobulin M (IgM) as marker of acute HAV infection; one was positive for anti-hepatitis B core antigen IgM and negative for hepatitis B surface antigen. None had markers of hepatitis C virus infection. Mortality rates in the overall study cohort (45%) and for those who tested anti-HAV IgM positive (41%) were similar. Forty-one percent of all patients and 46% of those positive for anti-HAV IgM underwent transplantation. The mortality rate in those with liver transplantation was half of that in patients who were not transplanted (28% versus 57%). Conclusions: HAV was the main etiologic agent of ALF in the population studied.

Exposure to MF59-adjuvanted influenza vaccines during pregnancy— A retrospective analysis

Pregnant women are at increased risk for complications and death associated with pandemic H1N1 influenza infection and they are prioritized for vaccination by public health authorities. Few data are available on the safety of adjuvants as components of pandemic vaccines that could be given systematically to pregnant women. Here we review nonclinical and clinical data on pregnancy outcomes associated with exposure to MF59, an adjuvant used in licensed H1N1 pandemic vaccines. Evaluation of the reproductive and developmental toxicity of MF59 alone and of a candidate MF59-adjuvanted H5N1 vaccine in animals demonstrated no evidence of teratogenicity or impact on fetal or early perinatal development. The clinical trial database encompassing all Novartis vaccine studies from 1991 to 2009 was searched to compare pregnancy outcomes in subjects exposed to MF59-adjuvanted or unadjuvanted influenza vaccines. Analysis of the clinical trial database found that the distribution of pregnancy outcomes (normal, abnormal, or ending in induced abortion) was similar in subjects exposed to MF59-adjuvanted and unadjuvanted influenza vaccine at any time in pregnancy and also, specifically, in early pregnancy: the respective proportions reported as a normal pregnancy outcome were 70% and 75%, respectively, overall, and 61% and 68%, respectively, in early pregnancy. Although data from the clinical database are too few to draw definitive conclusions on risks associated with exposure to MF59-adjuvanted influenza vaccines during pregnancy, available observations, so far, indicate no signals of a risk. Further data will be forthcoming from planned post-licensure studies of adjuvanted H1N1 vaccines as they are distributed in the pandemic response.

Assessment of the safety, tolerability and kinetics of the immune response to A/H1N1v vaccine formulations with and without adjuvant in healthy pediatric subjects from 3 through 17 years of age

Background: The recent global A/H1N1v pandemic led to major efforts to develop effective vaccines against the novel virus, while global demand and limited production capacity focused attention on dose sparing and schedules. Methods: An open-label phase III study of immunogenicity and safety of novel A/H1N1v vaccines included 392 Costa Rican children in two pediatric cohorts (3–8 and 9–17 years). They received two doses, of either an MF59®-adjuvanted formulation containing 7.5 μg antigen or non-adjuvanted formulations containing 15 or 30 μg antigen, three weeks apart. Immunogenicity was assessed as hemagglutination inhibition (HI) titers using the CBER licensure criteria. Results: All three vaccines elicited immune responses in 9–17 year-olds meeting CBER criteria three weeks after one dose; responses were not enhanced by second dose. In 3–8 year-olds only the adjuvanted vaccine met the CBER criteria after one dose, but all three vaccines met criteria after second dose. All vaccines were well tolerated; no related Serious Adverse Events (SAE) and few severe solicited reactions were reported. MF59-adjuvanted vaccine was associated with more reports of injection site pain and tenderness and overall systemic solicited reactions, most notably in older subjects, all of which decreased after the second dose. Conclusion: One dose of non-adjuvanted A/H1N1v vaccine is adequate in 9–17 year-olds, but younger children require either one dose of MF59-adjuvanted vaccine or two doses of non-adjuvanted vaccine to achieve protective titers. Enhanced immunogenicity with MF59 is associated with a small increase in reactogenicity, but no safety issues.

Humoral and intestinal immunity induced by new schedules of bivalent oral poliovirus vaccine and one or two doses of inactivated poliovirus vaccine in Latin American infants: an open-label randomised controlled trial

BACKGROUND Replacement of the trivalent oral poliovirus vaccine (tOPV) with bivalent types 1 and 3 oral poliovirus vaccine (bOPV) and global introduction of inactivated poliovirus vaccine (IPV) are major steps in the polio endgame strategy. In this study, we assessed humoral and intestinal immunity in Latin American infants after three doses of bOPV combined with zero, one, or two doses of IPV. METHODS This open-label randomised controlled multicentre trial was part of a larger study. 6-week-old full-term infants due for their first polio vaccinations, who were healthy on physical examination, with no obvious medical conditions and no known chronic medical disorders, were enrolled from four investigational sites in Colombia, Dominican Republic, Guatemala, and Panama. The infants were randomly assigned by permuted block randomisation (through the use of a computer-generated list, block size 36) to nine groups, of which five will be discussed in this report. These five groups were randomly assigned 1:1:1:1 to four permutations of schedule: groups 1 and 2 (control groups) received bOPV at 6, 10, and 14 weeks; group 3 (also a control group, which did not count as a permutation) received tOPV at 6, 10, and 14 weeks; group 4 received bOPV plus one dose of IPV at 14 weeks; and group 5 received bOPV plus two doses of IPV at 14 and 36 weeks. Infants in all groups were challenged with monovalent type 2 vaccine (mOPV2) at 18 weeks (groups 1, 3, and 4) or 40 weeks (groups 2 and 5). The primary objective was to assess the superiority of bOPV-IPV schedules over bOPV alone, as assessed by the primary endpoints of humoral immunity (neutralising antibodies-ie, seroconversion) to all three serotypes and intestinal immunity (faecal viral shedding post-challenge) to serotype 2, analysed in the per-protocol population. Serious and medically important adverse events were monitored for up to 6 months after the study vaccination. This study is registered with ClinicalTrials.gov, number NCT01831050, and has been completed. FINDINGS Between May 20, 2013, and Aug 15, 2013, 940 eligible infants were enrolled and randomly assigned to the five treatment groups (210 to group 1, 210 to group 2, 100 to group 3, 210 to group 4, and 210 to group 5). One infant in group 1 was not vaccinated because their parents withdrew consent after enrolment and randomisation, so 939 infants actually received the vaccinations. Three doses of bOPV or tOPV elicited type 1 and 3 seroconversion rates of at least 97·7%. Type 2 seroconversion occurred in 19 of 198 infants (9·6%, 95% CI 6·2-14·5) in the bOPV-only groups, 86 of 88 (97·7%, 92·1-99·4) in the tOPV-only group (p<0·0001 vs bOPV-only), and 156 of 194 (80·4%, 74·3-85·4) infants in the bOPV-one dose of IPV group (p<0·0001 vs bOPV-only). A further 20 of 193 (10%) infants in the latter group seroconverted 1 week after mOPV2 challenge, resulting in around 98% of infants being seropositive against type 2. After a bOPV-two IPV schedule, all 193 infants (100%, 98·0-100; p<0·0001 vs bOPV-only) seroconverted to type 2. IPV induced small but significant decreases in a composite serotype 2 viral shedding index after mOPV2 challenge. 21 serious adverse events were reported in 20 patients during the study, including two that were judged to be possibly related to the vaccines. Most of the serious adverse events (18 [86%] of 21) and 24 (80%) of the 30 important medical events reported were infections and infestations. No deaths occurred during the study. INTERPRETATION bOPV provided humoral protection similar to tOPV against polio serotypes 1 and 3. After one or two IPV doses in addition to bOPV, 80% and 100% of infants seroconverted, respectively, and the vaccination induced a degree of intestinal immunity against type 2 poliovirus. FUNDING Bill & Melinda Gates Foundation.