Effectiveness of the MF59-adjuvanted influenza vaccine in preventing emergency admissions for pneumonia in the elderly over 64 years of age

Case-control study designed to determine the effectiveness of an MF59-adjuvanted influenza vaccine in the population aged 65 years and older living in the community. Detailed health histories were obtained on both cases and controls that included a functional measure of co-morbidity (Barthel Index). Subjects were all eligible persons admitted to various hospitals with a diagnosis of pneumonia during the winter months and were matched by sex, hospital and admission week to controls admitted for non-medical reasons. The influenza vaccination programme using the MF59-adjuvanted influenza vaccine significantly reduced the probability of being hospitalised for pneumonia in the elderly over 64 years of age, even in a season with a low influenza activity, during which the predominant circulating strains were types B and A (H1N1).     

Effectiveness of MF59-adjuvanted subunit influenza vaccine in preventing hospitalisations for cardiovascular disease, cerebrovascular disease and pneumonia in the elderly

Annual circulation of influenza virus coincides with a peak in cardiovascular and pneumonia mortality/morbidity. This study aimed to determine the effectiveness of MF59-adjuvanted subunit influenza vaccine in preventing hospitalisation due to acute coronary syndrome (ACS), cerebrovascular accident (CVA) and pneumonia in the elderly. Three case-control studies were performed during the 2004-2005 influenza season in three health districts in Valencia, Spain (total elderly [>64 years of age] population: n=105,454). Controls were patients admitted for an acute surgical process or trauma within 10 days of case admission. In total, 159 patients were hospitalised for ACS, 148 for CVA and 242 for pneumonia. The risk of hospitalisation after the start of the influenza season was significantly lower in vaccinated patients compared with non-vaccinated patients (adjusted odds ratios: 0.13 [P=0.013] for ACS; 0.07 [P=0.007] for CVA; 0.31 [P=0.005] for pneumonia). During peak virus circulation, vaccination with MF59-adjuvanted subunit influenza vaccine was associated with an 87% relative risk reduction in hospitalisation for ACS, 93% for CVA, and 69% for pneumonia.     

Safety and immunogenicity of MF59-adjuvanted influenza vaccine in the elderly

Safety and immunogenicity of the influenza vaccine adjuvanted with MF59 (FLUAD) were compared to those of a non adjuvanted subunit vaccine in elderly subjects during three consecutive influenza seasons. Geometric mean titres and proportions of subjects with either a > or = four-fold increase in antibody titres or with an HI titre > or = 128 after immunisation were higher in FLUAD recipients. The adjuvant effect on the magnitude of the responses was most pronounced in subjects with pre-vaccination titres < or = 40. Although associated with more frequent mild local reactions, the adjuvanted vaccine was well tolerated. Thus, the addition of MF59 increased the immunogenicity of the subunit influenza vaccine in elderly persons with low pre-vaccination titres, who are at greatest risk of developing severe influenza disease and vaccine failure, without a clinically important increase in reactogenicity.     

Effectiveness of MF59-adjuvanted seasonal influenza vaccine in the elderly: A systematic review and meta-analysis

BackgroundIn the elderly, traditional influenza inactivated vaccines are often only modestly immunogenic, owing to immunosenescence. Given that adjuvantation is a means of enhancing the immune response, the trivalent inactivated vaccine adjuvanted with MF59 (MF59-TIV) was specifically designed to overcome this problem. Considering that, for ethical reasons, the absolute effectiveness of an influenza vaccine in the elderly cannot be demonstrated in placebo-controlled studies, the present study aimed to assess the effectiveness of MF59-TIV in preventing influenza-related outcomes in the elderly.MethodsWe conducted a systematic review of observational studies aimed at evaluating the effectiveness of MF59-TIV against influenza-related outcomes. Results of single studies were pooled whenever possible.ResultsOf the 1993 papers screened, 11 (6 case-control, 3 cohort and 2 prospective case-control) studies were identified. Hospitalization due to pneumonia/influenza and laboratory-confirmed influenza were reported in more than one study, while other outcomes (influenza-like illness, cardio- and cerebrovascular accidents) were investigated only by one study each. Pooled analysis of four case-control studies showed an adjusted MF59-TIV effectiveness of 51% (95% CI: 39–61%) against hospitalizations for pneumonia/influenza among community-dwelling seniors. Pooled results of the adjusted vaccine effectiveness against laboratory-confirmed influenza were also high (60.1%), although the 95% CI passed through zero (−1.3 to 84.3%). Other single community-based studies showed very high effectiveness of MF59-TIV in preventing hospitalizations for acute coronary [87% (95% CI: 35–97%)] and cerebrovascular [93% (95% CI: 52–99%)] events. MF59-TIV proved highly effective [94% (95% CI: 47–100%] in reducing influenza-like illness among institutionalized elderly. Furthermore, MF59-TIV displayed greater efficacy than non-adjuvanted vaccines in preventing hospitalizations due to pneumonia/influenza [adjusted risk ratio 0.75 (95% CI: 0.57–0.98)] and laboratory-confirmed influenza [adjusted odds ratio 0.37 (0.14–0.96)].ConclusionsOur results suggest that MF59-TIV is effective in reducing several influenza-related outcomes among the elderly, especially hospitalizations due to influenza-related complications.     

MF59-佐剂流感亚单位疫苗在中国老年人中的免疫原性和安全性研究

目的 比较MF59-佐剂流感亚单位疫苗与传统的非佐剂流感亚单位疫苗在老年人中的安全性和免疫原性.方法 采用随机、研究者设盲的对照研究,按照2:1的比例分别给予600名60岁以上老年人接种MF-59佐剂流感亚单位疫苗(复立达TM,简称佐剂流感疫苗)和传统的非佐剂流感亚单位疫苗(爱阁力保(R),简称传统亚单位疫苗),观察接种日和接种后7天内的局部反应和全身反应;使用血凝抑制试验检测接种老年人免疫前后的血凝抑制抗体(HI)滴度,计算基线无免疫保护状态受试者的抗体4倍增长阳转率、免疫后HI抗体达到保护水平(≥1:40)的保护率以及抗体GMT值和增长倍数.比较两者在安全性和免疫原性的差异.结果 两组疫苗的局部反应和全身反应相似,但传统亚单位疫苗组(n=200)中注射部位的硬结相对常见(P＜0.05),而佐剂流感疫苗组(n=400)中注射部位轻度疼痛和发热则相对较常见.对于基线无免疫保护状态的受试者,免疫后针对A/H3N2病毒株的抗体阳转率,佐剂流感疫苗组显著高于传统亚单位疫苗组(P＜0.001);除A/H1N1病毒株外,与基线相比,两组疫苗的保护率均有显著提高,但针对A/H3N2病毒株的保护率方面,佐剂流感疫苗显著高于传统亚单位疫苗(P＜0.001);两组疫苗接种后的GMT均比基线明显增加(P＜0.001),但佐剂流感疫苗组明显高于传统亚单位疫苗组.结论 中国老年人对佐剂流感疫苗耐受性良好,佐剂流感疫苗诱导的免疫原性水平比传统亚单位疫苗高,可使免疫力低下的老年人获益更大.     

Increased immunogenicity of the MF59-adjuvanted influenza vaccine compared to a conventional subunit vaccine in elderly subjects

Three-hundred and eight outpatient elderly subjects ( 65 years) were randomly assigned to receive the MF59-adjuvanted influenza vaccine (FLUAD; n = 204) or a conventional subunit influenza vaccine (AGRIPPAL S1; n = 104) in order to compare the safety and immunogenicity of the two vaccines. Although mild pain at the injection site was reported more frequently by subjects immunised with the adjuvanted vaccine, both vaccines were shown to be safe and well tolerated. The adjuvanted vaccine was more immunogenic as indicated by higher post-immunisation geometric mean titres (GMTs) and by higher proportions of subjects with post-immunisation four fold increases of antibody titres or subjects with 1/160 post-immunisation HI titres. These differences, statistically significant for all three strains after immunisation, indicated that, by addition of the MF59 adjuvant emulsion, conventional subunit influenza antigens acquire an enhanced immunogenicity without any clinically significant increase of their reactogenicity.     

Immunogenicity and safety of MF59-adjuvanted quadrivalent influenza vaccine versus standard and alternate B strain MF59-adjuvanted trivalent influenza vaccines in older adults

ObjectiveEvaluate whether adjuvanted quadrivalent influenza vaccine (aQIV) elicits a noninferior immune response compared with a licensed adjuvanted trivalent influenza vaccine (aTIV-1; Fluad™) and aTIV-2 containing an alternate B strain, examine whether aQIV had immunological superiority for the B strain absent from aTIV comparators, and evaluate reactogenicity and safety among adults ≥65 years.MethodsIn a multicenter, double-blind, randomized controlled trial, adults ≥65 years were randomized 2:1:1 to vaccination with aQIV (n = 889), aTIV-1 (n = 445), or aTIV-2 (n = 444) during the 2017-2018 influenza season. Immunogenicity was assessed by hemagglutination inhibition (HI) assay conducted on serum samples collected before vaccination and 21 days after vaccination for homologous influenza strains.ResultsaQIV met non-inferiority criteria for geometric mean titer ratios (GMT ratios) and seroconversion rate (SCR) differences against aTIV. The upper bounds of the 2-sided 95% confidence interval (CI) for GMT ratios were <1.5 for all 4 strains (A/H1N1 = 1.27, A/H3N2 = 1.09, B-Yamagata = 1.08, B-Victoria = 1.08). The upper bounds of the 95% CI of the SCR differences were <10% for all 4 strains (A/H1N1 = 7.76%, A/H3N2 = 4.96%, B-Yamagata = 3.27%, B-Victoria = 2.55%). aQIV also met superiority criteria (upper bound of 95% CI for GMT ratios <1 and SCR differences <0) for B strain absent from aTIV comparators (B-Yamagata GMT ratio = 0.70, SCR difference = −8.81%; B-Victoria GMT ratio = 0.78, SCR difference = −8.11%). aQIV and aTIV vaccines were immunogenic and well-tolerated. The immunological benefit of aQIV was also demonstrated in age subgroups 65–74 years, 75–84 years, and ≥85 years and in those with high comorbidity risk scores. Reactogenicity profiles were generally comparable.ConclusionaQIV induces a similar immune response as the licensed aTIV vaccine against homologous influenza strains and has a comparable reactogenicity and safety profile. Superior immunogenicity against the additional B strain was observed, indicating that aQIV could provide a broader protection than aTIV against influenza in older adults (NCT03314662).     

Impact of corticosteroids on the immune response to a MF59-adjuvanted influenza vaccine in elderly COPD-patients

The influence of steroids on the antibody response to a MF59-adjuvanted influenza vaccine in elderly COPD patients has not been studied previously. In the influenza season 2001/02 (October-February) elderly COPD patients were recruited at 14 doctor's offices and our 250-bed hospital. Patients were stratified into three groups according to current treatment regimen: (a) > 10 mg of prednisolone/day (SS); (b) inhaled steroids (IS); (c) no steroid treatment (control group, CG). All patients were vaccinated with the MF59-adjuvanted influenza vaccine. Antibodies against the influenza strains A/H1N1, A/H3N2, and B were measured at baseline, 4 and 24 weeks after vaccination by hemagglutination inhibition (HI) assay. One-hundred and sixty-two patients completed the study (CG n = 42; IS n = 87; SS n = 33). Mean age was 71.3 years (range 60-89). Twenty-one percent of all patients reported local reactions; no serious adverse events were observed. Four weeks after vaccination, mean geometric HI titres (GMT) for A/H1N1, A/H3N and B increased significantly in all groups (p < or = 0.05). After 24 weeks, GMTs to A/H1N1 and A/H3N2 returned to baseline, while GMTs to type B remained significantly higher than baseline in all groups. Significant differences between the groups as regards GMTs, seroconversion (56-89%) or seroprotection rates (64-93%) were not observed. Systemic steroids did not influence the antibody response towards the MF59-adjuvanted influenza vaccine. We found that the strains included in the vaccine showed varying long-term immunogenicity.     

Cost-effectiveness of introducing an MF59-adjuvanted trivalent influenza vaccine for older adults in Argentina

IntroductionInfluenza surveillance in Argentina reported influenza-like illness at a rate of 3500/100,000, a hospitalization rate of 15.5/100,000, and a death rate of 0.32/100,000 annually in adults aged over 65 years. The high burden of disease may be due to a combination of immunosenescence and the suboptimal clinical effectiveness of conventional, non-adjuvanted influenza vaccines in this age group. There is a clinical need for more effective influenza vaccines in this population. This study evaluated the cost-effectiveness of an MF59®-adjuvanted trivalent influenza vaccine (aTIV) in adults aged over 65 years in Argentina compared with the non-adjuvanted trivalent influenza vaccine (TIV) used under the current national vaccination policy.MethodsA decision tree cost-effectiveness model was developed to estimate the cost-effectiveness of switching from TIV to aTIV in Argentinian older adults. The model compared cost and health benefits of vaccination in one influenza season from the payer perspective. The main predictions included survival, quality-adjusted survival, and costs. Model inputs were sourced from Argentina or internationally where local data was considered inaccurate. Vaccine efficacy assumptions were extracted from recently published, peer-reviewed scientific literature.ResultsSwitching from TIV to aTIV would result in 170 deaths averted and 1310 incremental quality-adjusted life years (QALYs) gained. The incremental cost-effectiveness ratio per QALY was US $2660.59 from the payer perspective. In all sensitivity analyses, aTIV remained highly cost-effective. The probabilistic sensitivity analyses showed a 95% CI per QALY of US $113.74–7721.67.ConclusionIntroducing an adjuvanted influenza vaccine in Argentina is potentially beneficial and cost-effective relative to the currently-used TIV through the reduction of disease burden and utilization of healthcare resources.     

Comparison of the safety and immunogenicity of an MF59-adjuvanted with a non-adjuvanted seasonal influenza vaccine in elderly subjects

Aim

Adjuvanted influenza vaccines can overcome the poor antibody response of conventional non-adjuvanted vaccines in the elderly. We evaluated the immunogenicity, safety and clinical effectiveness of an MF59^®-adjuvanted trivalent influenza vaccine (aTIV) compared with a non-adjuvanted vaccine (TIV) in subjects ≥65 years old, with or without co-morbidities.

Methods

In 2010–2011, subjects (N = 7082) were randomized to receive one dose of aTIV or TIV. Co-primary objectives were to assess lot-to-lot consistency of aTIV, non-inferiority, superiority and immunogenicity 22 days after vaccination. Clinical effectiveness, reactogenicity and serious adverse events were monitored up to Day 366.

Results

The immunological equivalence of three lots of aTIV was demonstrated. aTIV was not only non-inferior to TIV but also elicited significantly higher antibody responses at Day 22 than TIV against all homologous and heterologous strains, even in subjects with co-morbidities. Superiority was not established. Reactogenicity was higher in the aTIV group, but reactions were mild to moderate and transient.

Conclusions

aTIV elicited a significantly higher antibody response than TIV, especially against A/H3N2 strains, although superiority by pre-defined criteria was not formally met. The study demonstrates potential immunological benefits of MF59-adjuvanted influenza vaccines for the elderly.This trial was registered with www.clinicaltrials.gov (NCT01162122).     

The adjuvanted influenza vaccines with novel adjuvants: experience with the MF59-adjuvanted vaccine

Elderly people and subjects with underlying chronic diseases are at increased risk for influenza and related complications. Conventional influenza vaccines provide only limited protection in the elderly population. In order to enhance the immune response to influenza vaccines, several adjuvants have been evaluated. Among these, an oil in water adjuvant emulsion containing squalene, MF59, has been combined with subunit influenza antigens and tested in clinical trials in comparison with non-adjuvanted conventional vaccines. Data from a clinical database of over 10000 elderly subjects immunised with this adjuvanted vaccine (Fluad, Chiron Vaccines, Siena, Italy) demonstrate that, although common postimmunisation reactions are more frequent in recipients of the adjuvanted vaccine, this vaccine is well tolerated, also after re-immunisation in subsequent influenza seasons. Immunogenicity analyses demonstrate a consistently higher immune response with statistically significant increases of postimmunisation geometric mean titres, and of seroconversion and seroprotection rates compared to non-adjuvanted subunit and split influenza vaccines, particularly for the A/H3N2 and the B strains. The higher immunogenicity profile of the MF59-adjuvanted vaccine is maintained also after subsequent immunisations. An even higher adjuvant effect was shown in subjects with low pre-immunisation titre and in those affected by chronic underlying diseases. In conclusion, the addition of MF59 to subunit influenza vaccines enhances significantly the immune response in elderly subjects without causing clinically important changes in the safety profile of the influenza vaccine.     

Antibody induction by virosomal, MF59-adjuvanted, or conventional influenza vaccines in the elderly

In a randomized, observer-blind, three-arm, parallel group, multi-centre trial including 386 elderly subjects in four countries, the immunogenicity and safety was studied of three different trivalent inactivated surface antigen (subunit) influenza vaccine types: a conventional subunit influenza vaccine (SIV, brand: Influvac and two newer vaccines: a MF59-adjuvanted subunit influenza vaccine (adSIV, brand: Fluad and a virosomal subunit influenza vaccine (vSIV, brand: Invivac. All vaccines were trivalent containing 15 microg hemagglutinin of each virus strain as recommended by the World Health Organization for the 2004-2005 season. The study was designed to demonstrate the serological non-inferiority of vSIV to both adSIV and SIV in elderly persons. The secondary objective was to investigate whether vSIV is superior to adSIV with respect to local reactogenicity. For all three vaccine strains, the post-vaccination geometric mean titres were comparable between SIV and adSIV and between vSIV and SIV. Seroprotection rates (i.e. percentages of subjects with a post-vaccination titre >or=40) varied between 84.1-100% indicating that the three vaccines all induced a strong antibody response. Local and systemic reactions were more frequently associated with adSIV (46 and 32%, respectively) than with vSIV or SIV ( approximately 20%). Vaccinations caused only little inconvenience as measured by questionnaire. In general, all vaccines were safe and well tolerated. In this trial, virosomal vaccine had similar immunogenicity to MF59-adjuvanted and conventional subunit vaccine and was considerably less reactogenic than the MF59-adjuvanted vaccine in the elderly.     

Comparison of the safety, tolerability, and immunogenicity of a MF59-adjuvanted influenza vaccine and a non-adjuvanted influenza vaccine in non-elderly adults

The adjuvanted influenza vaccine FLUAD is composed of subunit influenza antigens combined with the MF59-adjuvant emulsion. The vaccine was developed primarily for use in elderly populations, but non-elderly individuals might also benefit. To evaluate this hypothesis, 301 healthy adults were assigned randomly to receive two intramuscular injections of either FLUAD (150 subjects) or a non-adjuvanted vaccine, Fluzone (151 subjects), in two trials conducted at a 1-year interval. Injections consisted of 15 micrograms per 0.5 ml dose. Vaccine composition was A/Texas/36/91 (H1N1), A/Johannesburg/33/94 (H3N2), and B/Harbin/7/94 for the first injection and A/Texas/36/91 (H1N1), A/Nanchang/933/95 (H3N2), and B/Harbin/7/94 for the second injection. Immunogenicity was evaluated at 28 and 180 days post-immunization. FLUAD was generally well tolerated in healthy adults when compared with Fluzone. FLUAD was associated with increased pain at the injection site after immunization. A statistically significant increase in the incidence of injection-site warmth, chills, myalgia, and analgesic/antipyretic use occurred in the FLUAD group after the first injection but not after the second injection. In both groups, most of these local and systemic reactions were classified as mild. FLUAD was more immunogenic than Fluzone following both injections. After the first injection, statistically significant differences were found in the percentage of subjects with four-fold rises in hemagglutinin inhibition (HI) titers at 28 days post-immunization for the B antigen. After the second injection, the FLUAD group had significantly higher HI titers, a significantly higher percentage with a four-fold increase in titer, and a significantly greater percentage of subjects with titers >/=160 for the H3N2 antigen at 28 days. Only minor immunogenicity differences between the two groups were seen at 180 days. Compared with Fluzone, FLUAD was associated with increased immunogenicity and mild post-immunization reactions in healthy adults. The magnitude of increased immunogenicity in healthy adults was less than that seen in elderly populations.     

Immunogenicity and safety of concomitant MF59-adjuvanted influenza vaccine and 23-valent pneumococcal polysaccharide vaccine administration in older adults

BackgroundConcomitant administration of influenza and pneumococcal vaccines facilitates their uptake by older adults; however, data on immunogenicity and safety of concomitant administration of adjuvanted trivalent inactivated influenza vaccine (aIIV3) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) have not been reported.MethodsSubjects aged ≥65 years (N = 224) were randomized 1:1:1:1 to receive MF59-aIIV3 alone, MF59-aIIV3 + PPSV23 in contralateral arms, MF59-aIIV3 + PPSV23 in the same arm or PPSV23 alone (Clinical Trial Number – NCT02225327). Hemagglutination inhibition assay and multiplex opsonophagocytic killing assay were used to compare immunogenicity after single or concomitant vaccination.ResultsAll groups met immunogenicity criteria for the influenza vaccine in older adults with similar seroconversion rates and geometric mean fold-increases, irrespective of concomitant vaccinations and injection site. For each pneumococcal serotype, opsonic index (OI) increased markedly after the PPSV23 vaccination, irrespective of the concomitant influenza vaccine. All subjects showed an OI ≥ 8 for serotypes 6B, 18C and 19A post-vaccination, with a suggestion that the ipsilateral concomitant vaccination might be associated with higher OIs for some antigens. Local and systemic adverse events were more common in subjects receiving PPSV23 compared to those receiving aIIV3 alone.ConclusionsNo interference was observed with antibody responses to influenza or pneumococcal antigens when aIIV3 and PPSV23 were administered concomitantly.     

Immunogenicity, safety and tolerability of MF59-adjuvanted seasonal influenza vaccine in children with juvenile idiopathic arthritis

In order to evaluate the immunogenicity, safety, and tolerability of the MF-59 adjuvanted seasonal influenza vaccine in children and adolescents with juvenile idiopathic arthritis (JIA) treated with different anti-rheumatic drugs, 60 pediatric patients with JIA (30 treated with disease-modifying anti-rheumatic drugs [DMARDs] and 30 with etanercept) were compared with 30 healthy controls of similar gender and age. All of the patients received a single dose of the MF59-adjuvanted seasonal influenza vaccine (Fluad, Siena, Italy). Immunogenicity was assessed at baseline, and 1 and 3 months post-vaccination; safety and tolerability were also evaluated during the study period. The JIA patients treated with etanercept showed significantly lower geometric mean titres (GMTs) against the A/H1N1 strain than those treated with DMARDs (p < 0.05) and the healthy controls (p < 0.05), who had similar GMTs. The etanercept-treated JIA patients also showed a significant reduction in GMTs against the A/H1N1 and A/H3N2 strains from 1 to 3 months after vaccination (p < 0.05). Furthermore, their seroconversion and seroprotection rates, and B antigen GMTs, were all significantly lower than those of the subjects in the other two groups (p < 0.05). The safety and tolerability of the vaccine were good and similar between the groups. The results of this study indicate a reduced immune response to MF59-adjuvanted seasonal influenza vaccine in JIA children and adolescents treated with etanercept in comparison with those treated with DMARDs and healthy controls. The safety and tolerability of the vaccine appeared to be good in all of the study population.     

MF59-adjuvanted and virosomal influenza vaccines for preventing influenza hospitalization in older people: Comparative effectiveness using the Valencia health care information system

Background

Adjuvanted influenza vaccines offer greater and broader immunogenicity to older adults than conventional vaccines. Studies assessing the comparative effectiveness of adjuvanted influenza vaccines in this age group are lacking.

Methods

We conducted a retrospective cohort study to estimate the comparative effectiveness of MF59-adjuvanted trivalent influenza vaccine (TIV) and virosomal-TIV for prevention of influenza hospitalization in adults aged ≥65 years. We obtained administrative data on immunization status and influenza hospitalization for the 2010–2011 influenza season. We used Cox regression models to assess comparative effectiveness; crude and adjusted by age, sex, comorbidity, deprivation, type of insurance, and travel time to hospital. We accounted for data clustering at the hospital level by using a multilevel random effects model.

Results

Overall, 373,798 vaccinated subjects were evaluated. There were 40 hospitalizations for influenza among 176,618 subjects, contributing 4,288,109 person–weeks at risk in the virosomal-TIV group, and 37 hospitalizations for influenza among 197,180 subjects, contributing 4,786,360 person–weeks at risk in the MF59-TIV group. The crude hazard ratio (HR) was 0.83 (0.53–1.30), and the adjusted Cox estimated HR of MF59-TIV relative to virosomal-TIV was 0.86 (0.55–1.35). After accounting for data clustering, the HR of influenza hospitalization associated with MF59-TIV relative to virosomal-TIV was 0.94 (0.37–2.38).

Conclusion

During the 2010–2011 influenza season, we found no differences in the risk of influenza hospitalization in subjects aged ≥65 years vaccinated with MF59-TIV compared with those vaccinated with virosomal-TIV.     

Improved immunologic responses to heterologous influenza strains in children with low preexisting antibody response vaccinated with MF59-adjuvanted influenza vaccine

Vaccination is the most effective approach to reduce the substantial morbidity and mortality caused by influenza infection. Vaccine efficacy is highly sensitive to antigenic changes causing differences between circulating and vaccine viruses. Adjuvants such as MF59 increase antibody-mediated cross-reactive immunity and therefore may provide broader seasonal protection. A recent clinical trial showed that an MF59-adjuvanted vaccine was more efficacious than a nonadjuvanted comparator in subjects < 2 years of age, although not in those ≥ 2 years, during influenza seasons in which the predominant circulating virus was an A/H3N2 strain that was antigenically different from the vaccine virus. This finding suggested that the increased efficacy of the adjuvanted vaccine in younger subjects may be mediated by strain cross-reactive antibodies. A subset of the trial population, representing subjects with distinct age and/or immunological history, was tested for antibody responses to the vaccine A/H3N2 strain as well as A/H3N2 drifted strains antigenically matching the viruses circulating during the trial seasons. The neutralizing tests showed that, compared with nonadjuvanted vaccine, the adjuvanted vaccine improved not only the neutralizing antibody response to the vaccine strain but also the cross-reactive antibody response to the drifted strains in subjects with lower preexisting antibody titers, regardless of their age or vaccine history. The results demonstrated an immunological benefit and suggested a potential efficacy benefit by adjuvanted vaccine in subjects with lower preexisting antibody responses.     

MF59-adjuvanted influenza vaccine confers superior immunogenicity in adult subjects (18-60 years of age) with chronic diseases who are at risk of post-influenza complications

The immunogenicity and reactogenicity of two influenza vaccines were evaluated in a randomised, double-blind trial in north-east Italy during winter 2005-2006. Of 238 adult subjects (18-60 years of age) with underlying chronic diseases, 120 received MF59-adjuvanted subunit vaccine (Sub/MF59) and 118 received conventional subunit vaccine (Subunit). At 4 weeks post-vaccination, geometric mean titres (GMT) were significantly (P<0.001) increased for both groups. For the A/H3N2 and B strains, significantly (P<0.02) higher GMT were reported for the Sub/MF59 group. The mean-fold increase in titre, the percentage of subjects with at least a four-fold titre increase and the seroprotection rate (>or=1:40) were also higher in the Sub/MF59 group, with the seroprotection rate and four-fold titre increase achieving significance (P=0.002 and P=0.02, respectively) for the A/H3N2 strain. Our results suggest that adults affected by chronic diseases can mount a satisfactory immune response to influenza vaccines, and that these vaccines are well tolerated. Addition of the MF59-adjuvant, however, enhances the immunogenicity of subunit influenza vaccine, conferring superior protection than a conventional subunit vaccine in this population, who are at high-risk of influenza-related complications.     

MF59-adjuvanted influenza vaccine (FLUAD) in children: Safety and immunogenicity following a second year seasonal vaccination

After priming with two intramuscular doses of MF59^®-adjuvanted (Sub/MF59) or split influenza vaccines during the 2006/07 season, 89 healthy children received a third booster dose of the respective vaccine (2007/08 Northern Hemisphere formulation) approximately 1 year later, and were followed up for 6 months post-third injection. Immunogenicity was evaluated on 81 of them by a hemagglutination inhibition (HI) assay before and 3 weeks after vaccination.     

Immune response to influenza A (H1N1)v monovalent MF59-adjuvanted vaccine in HIV-infected patients

Immunogenicity of influenza A (H1N1)v MF59-adjuvanted vaccine was studied in HIV-infected patients. The vaccine was effective in inducing a protective immune response in patients with a CD4 >200 cells/μL while individuals with CD4 <200 cells/μL showed lower rates of seroconversion and seroprotection. These results underscore the usefulness of immunization against influenza in HIV-infected patients, though a boosting dose of vaccine may be required in seriously immunocompromised patients.