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Safety and Immunogenicity of a multigene multiclade HIV-1 DNA plasmid vaccine boosted with

heterologous HIV-1 MVA among healthy volunteers in Dar es Salaam,

Tanzania

Presentation to the 5th EDCTP forum, AICC, Arusha, Tanzania, 12th – 14th October 2009

M Bakari1, F Mhalu1, S Aboud1*, C Nilsson2, J Francis1, M Janabi1, E Lyamuya1*, EA Aris1, J Mbwana1*, D Buma1, L Mwanyika3, B Hejdeman4, A Bråve2, M Robb5, M Marovich5, N Michael5, P Earl6, B Moss6, R Stout7, B

Wahren2, G Biberfeld2, K Pallangyo1, E Sandström4, for the HIVIS study group.1Muhimbili University of Health and Allied Sciences and Muhimbili National Hospital, Departments of Internal Medicine, and 1*Microbiology and Immunology, Dar es Salaam, Tanzania; 2Swedish Institute for Infectious Disease Control (SMI) and Karolinska Institute (KI), Stockholm, Sweden; 3Tanzania Police Force; 4Venhälsan, Karolinska University Hospital, Department of Infectious Diseases, Stockholm, Sweden; 5US Military HIV Research Program, Rockville, MD, 6National Institute of Allergy and Infectious Diseases (NIAID)/National Institutes of Health (NIH), Bethesda, MD and 7Bioject, Portland, Oregon, USA.

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Objectives

To assess the safety and immunogenicity of a plasmid DNA-MVA prime boost HIV-1 vaccine candidate*

To build expertise and capacity in evaluating HIV vaccine candidates in Tanzania.

*Previously tested in Sweden with excellent results. Sandstrom et al, J Infect Dis 2008 November; 198(10):1482-1490

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ORI

CMV

Kanr

poly A

gene

7 plasmid HIV-1 DNA multigene/multiclade vaccine Inserted

pKCMV

gp160 env B

gp160 env A

gp160 env C

V1 – V5 A

V1 – V5 C

R511SA512M

rev B

p37 gag B

p37 gag A p24 Gag Ap17 Gag B

RTmut B

D185LD186L

Developed by B Wahren, Dept. of virology, SMI, Karolinska InstituteProduced by Vecura

gp120 gp41

LEFT ARM

RIGHT ARM

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MVA* / CMDR boostDeveloped by P Earl and B Moss, Laboratory of Viral Diseases, NIAID, NIHProduced by Walter Reed Army Institute of Research

Deletion IIIDeletion II

MVAgag protease / RTgp150 env

Subtype ECM235

Subtype ACM240

mH5 mH5

*Modified Vaccinia Ankara

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Inclusion Criteria

• Voluntary Informed Consent• Age <40 years• HIV negative by Antigen-Antibody ELISAs• Healthy by clinical and laboratory

assessment

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Study DesignRandomized, Double Blind, Placebo controlledArm Number DNA immunization MVA boost

I 20 DNA 3.8mg IM by Biojector MVA 108 pfu IM

II 20 DNA 1 mg ID by Biojector MVA 108 pfu IM

IIIa 10 Saline IM by Biojector Saline IM

IIIb 10 Saline ID by Biojector Saline IM

HIV-1 DNA/placebo

1 2 3 4 5 6 7 8 90 10month

HIV-1 MVA/placebo

Injections

Biojector

im

Left arm: Env/rev, 1 inj

Right arm: Gag/RT, 1 inj

id

Left arm: Env/rev, 3 inj

Right arm: Gag/RT, 2 inj

spacer

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Methods• IFN-γ ELISpot Assay

Baseline (visit 3)2 weeks after the last DNA vaccination (visit 9)2 weeks after the MVA boost (visit 12) 2 months after the MVA boost (visit 14); analysis ongoing6 months after the MVA boost (visit 15); analysis ongoing

Methods• IFN-gamma ELISpot (Mabtech, Nacka,

Sweden) responses measured on freshcells (within 6 hours of collection)stimulated with peptide pools.

• The criteria for positive ELISpotresponses were >55 spots/106 PBMCsand 4 times the medium background andthe baseline value.

Methods

Peptide pools used

Methods

• T-lymphocyte proliferative (TLP) responses to AT-2 inactivated HIV-1 antigen were tested by a standard 3H-thymidine uptake assay

• TLP was reported as stimulation index (SI) and SI above 6 was considered positive based on mean reactivity at baseline in 40 volunteers

Results, Safety*

• Safety profile has been good to date– Most adverse events were of Grade I

and II severity– There were eleven (11) Grade 3, Severe

Adverse Events, none of which was related to vaccination

*Oral presentation on safety profile

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HIV-specific IFN-γ ELISpotResponses

• 21/38 (55%) vaccinees had a positive IFN-γELISpot response after the third HIV- DNA vaccination.

• 35/35 (100%) had a positive IFN-γ ELISpot response after the HIV-MVA boost.

• All 15 placebo recipients were negative

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Gag

IG

ag II

Gag

WR

Env

IEn

v II

Env

IIIEn

v W

RPo

l WR

1

10

100

1000

Peptide pool

SFC

/mill

ion

PBM

Cs

Gag

IG

ag II

Gag

WR

Env

IEn

v II

Env

IIIEn

v W

RPo

l WR

1

10

100

1000

Peptide pool

SFC

/mill

ion

PBM

Cs

IFN-γ ELISpot reactivity inresponders 2 weeks after 3 x HIV-DNA and

responders 2 weeks after HIV-MVA

2 weeks after 3 x HIV-DNA 2 weeks after 1 x HIV-MVA

IFN-γ ELISpot reactivity to peptide pools in 35 responders 2 weeks after

HIV-1 MVA boost

• Any Gag 35 (100%) • Any Env 31 (89%)• Gag and Env 31 (89%)• Gag or Env 35 (100%)

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CD8+ and CD4+ T-cell IFN-γ ELISpot reactivity two weeks after HIV-MVA boost

in 13 tested vaccinees*

Responses to Gag

CD8+ CD4+9/13 13/13

Responses to Env

CD8+ CD4+3/11 11/11

* Determined by IFN-γ ELISpot testing before and after CD8 T-cell depletion

HIV-specific TLP Responses

• 24/52 (46%) individuals had positive TLP responses after the third HIV-DNA/placebo vaccination.Excluding 1/3 placebo 69%

• 35/48 (73%) had positive TLP responses after the HIV-MVA/placebo boost. Excluding 1/3 placebo 100%

Discussion• In comparison to the completed phase I

HIVIS trial conducted among 38 volunteers in Stockholm, Sweden:– After receipt of the DNA priming vaccine,

11 (30%) of 37 vaccinees had HIV-specific IFN-γ ELISpot responses

– After receipt of the MVA boosting vaccine, 34 (92%) of 37 vaccinees had HIV-specific IFN-γ ELISpot responses

– 35 (92%) of 38 had a positive LPA response

• Immunogenicity relatively higher in HIVIS03

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Conclusions• The high immunogenicity of

HIVIS03 DNA-MVA vaccine is consistent with the previous phase I study in Sweden

• Capacity built through HIVIS03 paved the way for EDCTP-funded TaMoVaC01 Project aimed at optimizing DNA vaccine delivery

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Acknowledgements• Police volunteers• EU and Sida• Swedish Embassy, Tanzania• WHO and AAVP• EDCTP• Investigators, collaborators and support staff

in:–Tanzania; at MUHAS, MNH, Tanzania Police Force–Sweden; at Karolinska Institute, Swedish Institute for Infectious Disease Control, Southern Hospital–United States of America; at WRAIR and LVD/NIH

• Tanzania Government, in particular the MoH & SW through NACP