Vaccines Against Influenza

Rino Rappuoli SUMMER SCHOOL ON INFLUENZA 2nd edition Siena, 16-20 July 2012

Siena

Piazza del Campo

Duomo

Torre del Mangia

Most people do not know what this construction is

From Sclavo to Sabin exploiting innovation to solve medical needs

Achille Sclavo

1904 I.S.V.T.

Istituto Sieroterapico e Vaccinogeno Toscano

Albert Sabin

2006

When you run out of ideas…

influenza virus

Influenza Type A

Matrix protein Neuraminidase (NA)

Hemagglutinin (HA)

M2 ion channel protein

Segmented RNA genome

(Influenza type B virus has a different ion channel protein)

Influenza A subtypes based on Humagglutinin – HA

Neuraminidase – NA (Subtypes H3N2, H5N1 etc )

The Influenza Hemagglutinin

Influenza HA structure

Species Distribution of Influenza Type A Hemagglutinin

Hemagglutinin Human Swine Equine Avian H1 + + - + H2 + - - + H3 + + + + H4 - - - + H5 - - - + H6 - - - + H7 - - + +

H8-H15 - - - +

The evolution of HA origin of pandemic H1N1

1968 Split

1976 Subunit

1958 Whole virus

New generation Vaccines against Influenza

1997 Adjuva

nted

2007 More adjuvants

VLPs High dose

Intradermal Recombinant

Pandemic Tetravalent QIV (+ B strain)

M2 (universal) M1 (universal)

Stem (universal)

2007 Cell

culture

New

Live

attenuated

World surveillance identifies antigenic variants

Epidemiologic behavior is assessed

Variants are sequenced and characterized immunologically

Specific strains for inclusion in vaccine are selected on the basis of the degree of difference from previous strains and evidence of epidemiological significance

Viruses are manipulated for high-yield growth in eggs and distributed to manufacturers

Reference reagents are generated for characterization of the vaccine product

Seed pools are expanded and inoculated into large numbers of embryonated hen’s eggs

Allantoic fluids are harvested and virions concentrated by centrifugation

Virions are chemically inactivated and disrupted with detergent, and subunit hemagglutinin and neuraminidase proteins are purified

Individual monovalent pools are blended, and content of trivalent preparation verified

Vaccine is packed, labeled, and delivered

January

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March

April

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October

* N Engl J Med 351: 2037-2040

(Nov 2004)

Cell culture influenza production Holly Springs facility Bulk building description

Annual bulk seasonal flu capacity of >50 M doses or 150 M doses (monovalent) within 6 months after declaration of a pandemic

Two cell culture lines (3 x 5,000L each)

Two downstream processing (purification) lines

Media preparation, buffer preparation/charging and equipment preparation

Virus seed stock production and cell culture expansion labs

Designed for BSL2+, capable to upgrade to BSL3 15

Holly Springs, United States

State of the Art Large-scale Flu Cell-culture and Adjuvant Manufacturing Facility in Holly Springs, North Carolina

Collaboration between US Department of Health and Human Services (USHHS) and Biomedical Advanced Research and Development Authority (BARDA)

Collaboration via sharing of initial capital investment and US commitment to annual pre-pandemic stockpile purchases

Site will have seasonal, pre-pandemic, and pandemic vaccine capability (150m doses within 6 month of declaration of influenza pandemic)

Construction of US-based flu cell-culture site began in 2007 • Ribbon cutting was on November 25, 2009 • Ready to respond to pandemic as early as

2011 • Full scale commercial production by 2013

Construction and 15yr operation of this facility represents financial commitment of ~USD $1.1 billion for design, construction, start-up, and validation of the facility.

Efficacy in the elderly

10-year study, 713,872 person-seasons, average age 73

27% reduction in hospitalization 48% reduction in risk of death

Efficacy in infants by vaccinating pregnant women

Impriving influenza vaccines with new adjuvants MF59: An established adjuvant

Oil-in-water emulsion adjuvant licensed for use in seasonal influenza vaccine FLUAD* since 1997 • More than 150 million commercial doses

distributed

Adjuvanted vaccine provides heterologous responses to drifted strains

>120 Clinical studies, >200,000 subjects • No safety signals in either

pharmacovigilance database or meta-analysis of clinical trial database with 6 month subject follow-up (filed with CBER)

Pediatric studies and efficacy trial in 3,000 subjects

MF59 adjuvant emulsion

SPAN 85 TWEEN 80 Antigens

160nm

*FLUAD is a registered trademark of Novartis. FLUAD is not licensed in the Unites States. FLUAD is recommended for active prophylaxis of influenza in the elderly

oil

Improving influenza vaccines with new adjuvants

1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s

Aluminium Salts MF59

Many potent vaccine adjuvants have failed, due to safety concerns

MF59 was a key innovation, first novel adjuvant in 70 years

Alum and MPL (AS04®) are the only adjuvants currently approved in US

Fluad® (influenza Fendrix ® (HBV) Cervarix® (HPV)

Prepandrix® (pandemic influenza)

MPL+Alum (ASO4) Cervarix

The Slow Pace of Adjuvant Development

The MF59 adjuvant makes the old immune system to behave like a young one !!!!

young

old + MF59

old

Preclinical studies show that MF59 nanoparticles are the strongest adjuvant for subunit flu vaccine

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FLUAD Immunogenicity Meta-Analysis - All Subjects

Superior Immune Response Against Conventional Vaccines

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1st immunisation 2st immunisation 3st immunisation

Fluad® safety meta-analysis: no severe reactions

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Control SevereReaction (n= 1437)Control Mild/Mod.Reaction (n= 1437)FLUAD SevereReaction (n= 2112)FLUAD Mild/Mod.Reaction (n= 2112)

Podda, Vaccine 19: 2673-80, 2001

Enhancement of adjuvant effect in elderly with low pre-immunization titer

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A) Proportion of subjects with 4-fold increase or seroconversion

B) Proportion of subjects with HI Titre >= 160

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**

**

** Pretiter ≤ 20 vs Pretiter >40, P<0.01

MF59-adjuvanted vaccine in children Seroprotection rates after one and two doses

H3N2 H1N1 B

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FLUAD

Vaxigrip

MF59 induces higher levels of cross-reactive antibodies against drifted strains in children

Pre Pre Pre Post Post Post

Perc

enta

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ith H

I >40

to

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mat

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str

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a: p < 0.001 b: p < 0.05

MF59 works against drifetd viruses Fujan example

Immunogenicity (haemagglutination inhibiting antibody titers) of 3 Chiron Vaccines inactivated influenza vaccines against H3N2 homologous vaccine strain (A/Panama) and against H3N2 heterovariant strain (A/Wyoming) Agrippal™ subunit

vaccine (n = 29)

Begrivac™ split vaccine (n = 30)

Fluad™ adjuvanted subunit vaccine (n =

30) A/Panama

(H3N2) A/Wyoming@

(H3N2) A/Panama

(H3N2) A/Wyoming

(H3N2) A/Panama

(H3N2) A/Wyoming

(H3N2) Pre-

vaccination

GMT 95% CI

87.2 56.4-134.8

52 31.9-85

48.1 32.8-70.6

20.3 13.9-29.6

65.2 42.2-100.9

40.2 25.5-63.1

Seroprotection rate§

No/Total (%)

23/29 (79.3%)

19/29 (65.5%)

22/30 (73.3%)

11/30 (36.7%)

21/30 (70%)

16/30 (53.3%)

Post-

vaccination

GMT 95% CI

174 1118.3-255.9

122.3 77.3-193.6

141.2 100.4-198.5

82.2 52.6-128.5

248.7 177.5-348.5

176.9 122.6-255.3

Seroprotection rate§

No/Total (%)

28/29 (96.5%)

22/29 (75.9%)

29/30 (96.7%)

24/30 (80%)

30/30 (100%)

30/30 (100%)

§ Seroprotection rate: proportion of subjects with a protective HI titre ≥ 40 @ A/Wyoming /3/2003 is an A/Fujian/411/2002-like strain. * GMR: geometrical mean ratio (post-vaccination GMT / pre-vaccination GMT)

Efficacy in the elderly

10-year study, 713,872 person-seasons, average age 73

MF 59 can address low vaccine efficacy due to antigenic drift

The risk of subjects ≥65 years of age developing an unsolicited reaction was similar for MF59- and non-adjuvanted vaccines Green indicates statistical evidence of a decreased risk with MF59-adjuvanted vaccine;

red indicates statistical evidence of an increased risk with MF59-adjuvanted vaccine. Significance claimed if 95% CI excluded 1. * Compared to non-adjuvanted vaccine; † includes or ‡ excludes study V7P35 (ClinicalTrials.gov Identifier: NCT00481065). Risk ratio: risk of developing a disease after exposure to a vaccine. Pellegrini M. et al. Vaccine 2009; 27:6959–6965.

Relative risk of adverse events following vaccination with MF59-adjuvanted or non-adjuvanted vaccines

Pooled analysis of 38 randomized, controlled influenza trials, subjects ≥65 years of age

1.0 1.2 1.4 1.6 1.8 2.0 0.0 0.2 0.4 0.6 0.8

All unsolicited adverse events‡ Including:

Solicited local reactions

• Cardiovascular diseases‡

• New onset of chronic diseases§

• Deaths§

• Serious adverse events§

• Hospitalizations§

Solicited systemic reactions

Lower risk with MF59-adjuvanted*

Higher risk with MF59-adjuvanted*

Risk ratios

From June to December 2009 3 H1N1 vaccines were:

Developed

Tested in clinical trials

Licensed

180 million doses produced

MF59 allowed dose sparing

Priming with H5N3

Adjuvanted H5N1 vaccine prime-boost regime induces broad H5N1 coverage

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Heterologous H5N1 – Clade 2.2

Heterologous H5N1 – Clade 2.3

Heterologous H5N1 – Clade 2.1

Days

Boost with H5N1 clade 1 with MF59

6-8 years

Months

Protective titer (1:40)

With MF59

w/o MF59

By day 7 post-boost most of subjects have already protective neutralizing antibody titers against all virus strains

In 2006 we vaccinated with clade 1 H5N1 vaccine those people that had been vaccinated with clade 0 H5N1 in 1999

1999 Priming Clade 0

2006 Boost Clade 1

universal vaccine for H5?

Fluad

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Days post-second dose

Vesikari T, et al. NEJM.

Adjuvant improves vaccine efficacy in infants

Vaccination with adjuvant: more CD4+ T cells, more antibodies....... a different game

Non-Adj-15

MF59-7.5

MF59-15

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A/VN

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Galli et al, Proc Natl Acad Sci USA 2009

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CD

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MN antibodies

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MF59-H5N3 primed H5N3 primed Unprimed

Memory B cells are present only in those primed with adjuvanted H5N1vaccine

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Galli et al, Proc Natl Acad Sci USA 106 (19): 7962-7967, 2009

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Priming with H5N3

Memory T cells are induced first Memory B cells are more abundant following adjuvant priming

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6-8 years

Months

Protective titer (1:40)

With MF59

w/o MF59

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The HA2 stem is immunogenic but the response is mostly ineffective

HA1

MF59 mechanism of action genes modulated by adjuvants at injection site

MF59 was the most potent activator of mouse transcriptome at injection site

All adjuvants tested modulate a common set of 168 “adjuvant core response genes”

Mosca et al. PNAS 2008

MF59 is a strong inducer of cytokines & cytokine receptor genes at injection site (mouse muscle)

Mosca et al. PNAS

MF59 is a potent inducer of genes involved in leukocyte transendothelial migration at injection site

MF59 is the most potent and rapid inducer of Itgam/CD11b mRNA Suggest a more rapid recruitment of CD11b+ blood cells into the muscle compared to CpG and Alum

Mosca et al. PNAS 200

MF59 induces a rapid recruitmnent of CD11b+ blood cell injection site

Blue: Utrophin Red: PI Green: αCD11b

Mosca et al. PNAS 20

Towards an universal vaccine?

The HA stem as target of universal antibodies?

F16, a truly universal antibody against influenza

F16 recognizes a flat surface on the stem of HA

47

Herfst et al (2012). Airborne Transmission of Influenza A/H5N1 Virus Between Ferrets. Science 336: 1534-1541.