A heterologous MF59-adjuvanted H5N1 prepandemic influenza booster vaccine induces a robust, cross-reactive immune response in adults and the elderly.
ABSTRACT Immunogenicity and safety of a booster dose of an MF59-adjuvanted H5N1 vaccine containing 7.5 μg A/turkey/Turkey/1/2005-like (clade 2.2) H5N1 hemagglutinin, given approximately 18 months after primary vaccination with a heterologous strain, were evaluated. The booster vaccine was well tolerated and induced a robust, cross-reactive immune response.
- [Show abstract] [Hide abstract]
ABSTRACT: MF59 is an oil-in-water (o/w) emulsion, pre-pared with a low content of the biodegradable oil, squalene (4.3% w/w), which is a naturally occur-ring substance normally found in plants and ani-mals including humans. In humans, squalene is an intermediate in the steroid hormone biosyn-thetic pathway and is a direct synthetic precursor to cholesterol. A normal human is estimated to produce in excess of 1 g of squalene per day, while the amount of squalene contained in the licensed MF59-adjuvanted seasonal influ-enza vaccine is approximately 10 mg per dose. In comparison, the normal dietary intake of squalene in humans is 50–200 mg/day, depend-ing on diet. MF59 is a well-established, safe and potent vaccine adjuvant that has been licensed in more than 20 countries, for more than 13 years for use in an influenza vaccine focused on elderly subjects (Fluad ® , Novartis, Cambridge, MA, USA). During the 2009 H1N1 influenza pandemic, two MF59-adjuvanted vaccines were licensed and used safely in all age groups (down to 6 months of age) including pregnant women. Furthermore, MF59 has been shown to be safe in a seasonal influenza vaccine in infants and children and increased vaccine efficacy from 43 to 89% [1–3]. The overall safety profile of MF59 has been clinically established with a large safety database (>40,000 subjects) and through an extensive pharmacovigilance evalu-ation in excess of 60 million doses distributed commercially as Fluad ® . In addition, approxi-mately 100 million doses of H1N1 pandemic vaccines (Focetria ® and Celtura ® , Novartis) were distributed. The MF59 adjuvant significantly enhances the immunogenicity of influenza vaccines in the elderly, who typically respond poorly to traditional influenza vaccines, owing to age-related impairment of their immune sys-tems (immuno senescence) . Moving beyond seasonal influenza vaccines, MF59 has also been shown to significantly improve the immunoge-nicity of pandemic influenza vaccines and has enabled vaccines with a relatively low antigen content to achieve titers expected to offer pro-tection, and with fewer doses [5–7]. Moreover, the addition of MF59 to the vaccine allows for greater cross-reactivity against viral strains not actually included in the vaccine (Figures 1–4) [6,8]. This is a key attribute, since it is difficult to pre-dict exactly which strain might emerge and cause a pandemic. Following the emergence of the H1N1 pandemic in 2009, an MF59-adjuvanted influenza vaccine received approval for licensure
- [Show abstract] [Hide abstract]
ABSTRACT: Influenza pandemic preparedness involves priming of the population with pre-pandemic vaccines. Such vaccines should be well tolerated and induce a long-lasting immunological memory that can effectively be boosted with a single dose of pandemic vaccine once available. The presented studies assessed different prime-boost regimens with a Vero cell-derived whole virus non-adjuvanted H5N1 vaccine. In one study, 281 healthy adult (18-59 years) and 280 elderly (≥60 years) subjects received two vaccinations, 21 days apart, with Vero cell-derived whole virus non-adjuvanted H5N1 vaccine (7.5μg HA antigen A/Vietnam/1203/2004) followed by a 6, 12-15, or 24 month booster (7.5 or 3.75μg A/Indonesia/05/2005 or A/Vietnam/1203/2004). In the other study, 230 healthy adults (18-59 years) received single dose priming (7.5μg A/Vietnam/1203/2004) followed by a 12 month booster (7.5 or 3.75μg A/Indonesia/05/2005). Antibody responses were assessed by microneutralization (MN) and single radial hemolysis (SRH) assay. Vaccine safety was assessed throughout. Two dose priming was equally immunogenic in adults and the elderly: >72% of subjects in each population achieved MN titers ≥1:20 after the second vaccination. Booster vaccinations at 6, 12-15, and 24 months induced substantial antibody increases to both strains: after a 7.5μg A/Indonesia/05/2005 booster, 93-95% of adults and 72-84% of the elderly achieved MN titers≥1:20 against this strain. Homologous and heterologous booster responses were higher in the 7.5μg dose group than in the 3.75μg dose group. Booster responses following single dose priming were similar; a 7.5μg booster dose induced homologous MN titers ≥1:20 in 93% of subjects. A Vero cell derived whole virus non-adjuvanted H5N1 influenza vaccine is well tolerated and induces long-lasting cross-clade immunological memory that can be effectively boosted 1-2 years after two dose or single dose priming, supporting its suitability for pre-pandemic vaccination.Vaccine 08/2012; 30(43):6127-35. · 3.77 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: MF59 is a well-established, safe and potent vaccine adjuvant that has been licensed for more than 13 years for use in an influenza vaccine focused on elderly subjects (Fluad®), Novartis, Cambridge, MA, USA). Recently, MF59 was shown to be safe in a seasonal influenza vaccine for young children and was able to increase vaccine efficacy from 43 to 89%. A key and consistent feature of MF59 is the ability of the emulsion to induce fast priming of influenza antigen-specific CD4(+) T-cell responses, to induce strong and long-lasting memory T- and B-cell responses and to broaden the immune response beyond the influenza strains actually included in the vaccine. The enhanced breadth of response is valuable in the seasonal setting, but is particularly valuable in a (pre-) pandemic setting, when it is difficult to predict which strain will emerge to cause the pandemic. We have shown that the ability of MF59 to increase the breadth of immune response against influenza vaccines is mainly due to the spreading of the repertoire of the B-cell epitopes recognized on the hemagglutinin and neuraminidase of the influenza virus.Expert Review of Vaccines 04/2011; 10(4):447-62. · 4.22 Impact Factor
CLINICAL AND VACCINE IMMUNOLOGY, Nov. 2010, p. 1817–1819
Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Vol. 17, No. 11
A Heterologous MF59-Adjuvanted H5N1 Prepandemic Influenza
Booster Vaccine Induces a Robust, Cross-Reactive Immune
Response in Adults and the Elderly?
Elena Fragapane,1* Roberto Gasparini,2Francesco Schioppa,3Franco Laghi-Pasini,4
Emanuele Montomoli,5and Angelika Banzhoff6
Novartis Vaccines and Diagnostics, Siena, Italy1; Department of Health Sciences, Section of Hygiene and Preventive Medicine,
University of Genoa, Genoa, Italy2; University of Annunzio, Chieti, Italy3; Department of Allergology and Clinical Immunology,
Le Scotte University Hospital, University of Siena, Siena, Italy4; Department of Pathophysiology, Experimental Medicine and
Public Health, Laboratory of Molecular Epidemiology, University of Siena, Siena, Italy5; and
Novartis Vaccines and Diagnostics, Marburg, Germany6
Received 9 November 2009/Returned for modification 3 January 2010/Accepted 14 August 2010
Immunogenicity and safety of a booster dose of an MF59-adjuvanted H5N1 vaccine containing 7.5 ?g
A/turkey/Turkey/1/2005-like (clade 2.2) H5N1 hemagglutinin, given approximately 18 months after primary
vaccination with a heterologous strain, were evaluated. The booster vaccine was well tolerated and induced a
robust, cross-reactive immune response.
Immunization against pandemic virus strains, such as H5N1,
is a keystone of pandemic preparedness plans (5, 7, 12). In
addition, due to the need to rapidly produce many doses,
vaccine hemagglutinin (HA) content may be a limiting factor,
which may be countered by the inclusion of an adjuvant, such
as MF59. Considering the unpredictable emergence and rapid
spread of pandemic influenza together with the time needed to
produce and distribute a pandemic influenza vaccine, proactive
prepandemic vaccination presents a valuable opportunity to
reduce the impact of pandemic influenza disease. In addition
to having an excellent safety profile, a prepandemic vaccine
should offer broad, robust immunity that can be easily boosted
with a flexible dosing schedule (5).
(This work was presented in part at Influenza Vaccines for
the World [IVW 2009], 27 to 30 April 2009, Cannes, France.)
An H5N1 vaccine containing the MF59 adjuvant (Aflunov;
Novartis Vaccines and Diagnostics) was developed and admin-
istered to healthy volunteers in a clinical trial setting. The
present study was an extension of a trial (NCT00311480) in
which 486 subjects over 18 years of age received two primary
doses of the MF59-adjuvanted H5N1 vaccine, formulated with
7.5 ?g or 15 ?g HA per dose of the A/Vietnam/1194/2004
(clade 1), at an interval of 3 weeks; a subset of 223 subjects
received a homologous booster dose at 6 months (2). Those
who did not receive the booster dose at 6 months were eligible
for inclusion in this extension study (NCT 00561184), which
evaluated the safety and immunogenicity of one 0.5-ml dose of
MF59-adjuvanted H5N1 vaccine, containing 7.5 ?g of HA
from the A/turkey/Turkey/1/2005-like strain (clade 2), approx-
imately 18 months after primary vaccination. The inclusion and
exclusion criteria and laboratory and safety surveillance meth-
ods used in this extension study were similar to those of the
initial study (2). There was no statistical null hypothesis for the
immunogenicity assessments, which were based on European
Committee for Medicinal Products for Human Use (CHMP)
criteria (4), and the calculations of all statistical parameters
and confidence intervals are descriptive.
Following completion of the primary vaccination course in
the initial study using the MF59-adjuvanted H5N1 vaccine
formulated with A/Vietnam/1194/2004 (clade 1), all CHMP
criteria were met (2). Following the primary course, hemag-
glutination inhibition (HI) antibody for the priming strain,
A/Vietnam/1194/2004 (clade 1), declined to low levels by the
time of the booster dose (Table 1). Antibody levels increased
1 week following the booster vaccination for both the booster
(A/turkey/Turkey/1/2005-like [clade 2.2]) and heterologous
priming (A/Vietnam/1194/2004 [clade 1]) strains and remained
high 3 weeks postbooster (Table 1). The CHMP criterion for
the seroprotection rate by HI was met 3 weeks following the
booster vaccination for the A/turkey/Turkey/1/2005-like (clade
2.2) and A/Vietnam/1194/2004 (clade 1) strains in elderly sub-
jects and for the A/Vietnam/1194/2004 (clade 1) strain in non-
elderly subjects. The seroprotection rates 3 weeks after booster
vaccination were comparable to those reached after comple-
tion of the primary vaccination course (2). The CHMP crite-
rion for the seroconversion rate by HI was met for both strains
1 week after the booster dose in the nonelderly subjects. Sero-
conversion rate criteria were met for both strains for elderly
and nonelderly subjects 3 weeks after the booster dose. Immu-
nogenicity, when measured using the SRH and MN assays,
showed similar trends (data not shown). Overall, the results
from this study compare favorably with those in other clinical
* Corresponding author. Mailing address: Novartis Vaccines and
Diagnostics, Via Fiorentina, 1, 53100 Siena, Italy. Phone: 39 0577
245114. E-mail: firstname.lastname@example.org.
?Published ahead of print on 1 September 2010.
trials, with similar immune responses after primary vaccination
and booster doses (6, 9). These results suggest that subjects
were effectively primed, which facilitated a rapid immune re-
sponse to the heterologous A/turkey/Turkey/1/2005-like (clade
2.2) strain after a single dose.
The incidence of solicited reactions reported within 7 days of
booster administration was 72% (22/29) in nonelderly subjects
and 39% (7/18) in elderly subjects. The most frequently re-
ported local reactions for all subjects were pain and induration
(Fig. 1). The most frequently reported solicited systemic reac-
tions were myalgia and headache for nonelderly subjects and
myalgia and fatigue for elderly subjects (Fig. 1). No subject
reported fever. All reactions were transient (?2 days) and
were considered mild to moderate in intensity. No unsolicited
AEs and SAEs were considered to be vaccine related. The
incidence of AEs compares favorably with the results from the
initial study (2). Overall, the safety assessments confirmed that
the A/turkey/Turkey/1/2005-like (clade 2.2) booster was well
tolerated when administered after primary vaccination with
A/Vietnam/1194/2004 (clade 1), supporting the safety profile
of MF59-adjuvanted vaccines (8, 10).
Several studies have demonstrated that the inclusion of
MF59 in a seasonal or pandemic influenza vaccine increases
both the homologous and heterologous immune responses (1,
3, 9–11) even at low antigen doses. The findings from this
extension study provide further support for both the immuno-
potentiating capabilities of MF59 and the potential for adop-
tion of antigen-sparing strategies in a prepandemic context.
This study further illustrates how prepandemic vaccination
may prime a population, providing initial protection against an
influenza pandemic that can be boosted with a different strain.
This prime-boost strategy is likely to be the most effective way
to protect populations against future influenza pandemics.
A. Banzhoff had full access to all data in the study and takes re-
sponsibility for the integrity of the data and the accuracy of the data
analysis. R. Gasparini was the principal investigator. All authors par-
ticipated in the analysis and interpretation of the data and/or were
involved in drafting and revising the manuscript for important intel-
Novartis Vaccines and Diagnostics sponsored this study.
E. Fragapane and A. Banzhoff are employees of Novartis Vaccines
and Diagnostics, the sponsor of the study; R. Gasparini has no conflict
of interest; F. Schioppa received funding from Novartis Vaccines and
Diagnostics to perform the study; E. Montomoli received funding from
Novartis Vaccines and Diagnostics to perform single radial hemolysis
TABLE 1. Hemagglutination inhibition response by MF59-adjuvanted H5N1 subunit influenza vaccine formulation and age cohorta
Value for age cohortb
Seroprotection rate, %
1 week after booster GMT
Seroprotection rate, %
Seroconversion rate, %
3 weeks after booster GMT
Seroprotection rate, %
Seroconversion rate, %
aPrimary vaccination with H5N1 A/Vietnam, 7.5 or 15 ?g on study days 1 and 22; booster with H5N1 A/turkey/Turkey, 7.5 or 15 ?g on study day 382. GMT, geometric
mean titer; GMR, geometric mean ratio. Two-sided 95% confidence intervals are shown in parentheses. CHMP criteria: nonelderly, GMR ? 2.5; seroprotection ? 70%;
seroconversion ? 40%; elderly, GMR ? 2.0; seroprotection ? 60%; seroconversion ? 30%.
bNonelderly cohort (n ? 29), 18 to 60 years of age; elderly cohort (n ? 17), ?60 years of age.
FIG. 1. Reported incidences of local and systemic reactions for
nonelderly adults (18 to 60 years of age; white bars) and elderly adults
(?60 years of age; black bars).
1818NOTESCLIN. VACCINE IMMUNOL.
analysis; F. Laghi-Pasini has received a travel grant from Novartis
Vaccines and Diagnostics.
1. Atmar, R. L., W. A. Keitel, S. M. Patel, et al. 2006. Safety and immunoge-
nicity of nonadjuvanted and MF59-adjuvanted influenza A/H9N2 vaccine
preparations. Clin. Infect. Dis. 43:1135–1142.
2. Banzhoff, A., R. Gasparini, F. Laghi-Pasini, et al. 2009. Pre-pandemic influ-
enza immunization: MF59-adjuvanted H5N1 vaccine induces immunogenic
memory and heterotypic antibody response in non-elderly and elderly adults.
PLoS One 4:e4384.
3. Banzhoff, A., M. Pellegrini, G. Del Giudice, E. Fragapane, N. Groth, and A.
Podda, 2008. MF59-adjuvanted vaccines for seasonal and pandemic influ-
enza prophylaxis. Influenza Other Respir. Viruses 2:243–249.
4. Committee for Proprietary Medicinal Products. 1997. Note for guidance on
harmonization of requirements for influenza vaccines CPMP/BWP/214/96.
European Agency for the Evaluation of Medicinal Products, London, United
5. Jennings, L. C., A. S. Monto, P. K. Chan, T. D. Szucs, and K. G. Nicholson.
2008. Stockpiling prepandemic influenza vaccines: a new cornerstone of
pandemic preparedness plans. Lancet Infect. Dis. 8:650–658.
6. Lin, J. T., C. G. Li, X. Wang, et al. 2009. Antibody persistence after 2-dose
priming and booster response to a third dose of an inactivated, adjuvanted,
whole-virion H5N1 vaccine. J. Infect. Dis. 199:184–187.
7. Monto, A. S. 2009. The risk of seasonal and pandemic influenza: prospects
for control. Clin. Infect. Dis. 48(Suppl. 1):S20–S25.
8. Nicholson, K. G., A. E. Colegate, A. Podda, et al. 2001. Safety and antige-
nicity of non-adjuvanted and MF59-adjuvanted influenza A/Duck/Singa-
pore/97 (H5N3) vaccine: a randomised trial of two potential vaccines against
H5N1 influenza. Lancet 357:1937–1943.
9. Nolan, T., P. C. Richmond, M. V. Skeljo, et al. 2008. Phase I and II ran-
domised trials of the safety and immunogenicity of a prototype adjuvanted
inactivated split-virus influenza A (H5N1) vaccine in healthy adults. Vaccine
10. Stephenson, I., R. Bugarini, K. G. Nicholson, et al. 2005. Cross-reactivity to
highly pathogenic avian influenza H5N1 viruses after vaccination with non-
adjuvanted and MF59-adjuvanted influenza A/Duck/Singapore/97 (H5N3)
vaccine: a potential priming strategy. J. Infect. Dis. 191:1210–1215.
11. Stephenson, I., K. G. Nicholson, A. Colegate, et al. 2003. Boosting immunity
to influenza H5N1 with MF59-adjuvanted H5N3 A/Duck/Singapore/97 vac-
cine in a primed human population. Vaccine 21:1687–1693.
12. World Health Organization. Accessed 17 March 2008. Responding to the
avian influenza pandemic threat: recommended strategic actions. http://www
.pdf. World Health Organization, Geneva, Switzerland.
VOL. 17, 2010NOTES1819