Needle-Free Devices and CpG-Adjuvanted DNA Improve Anti-HIV Antibody Responses of Both DNA and Modified Vaccinia Ankara-Vectored Candidate Vaccines

Rosamund Chapman; Michiel van Diepen; Nicola Douglass; Tandile Hermanus; Penny L Moore; Anna-Lise Williamson

doi:10.3390/vaccines11020376

Needle-Free Devices and CpG-Adjuvanted DNA Improve Anti-HIV Antibody Responses of Both DNA and Modified Vaccinia Ankara-Vectored Candidate Vaccines

Vaccines (Basel). 2023 Feb 7;11(2):376. doi: 10.3390/vaccines11020376.

Authors

Rosamund Chapman^{1

2}, Michiel van Diepen^{1

2}, Nicola Douglass^{1

2}, Tandile Hermanus^{3

4}, Penny L Moore^{3

4

5}, Anna-Lise Williamson^{1

2}

Affiliations

¹ Institute of Infectious Disease and Molecular Medicine, Faculty of Health Science, University of Cape Town, Cape Town 7925, South Africa.
² Division of Medical Virology, Department of Pathology, University of Cape Town, Cape Town 7925, South Africa.
³ Centre for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2131, South Africa.
⁴ Antibody Immunity Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa.
⁵ Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Congella, Durban 4013, South Africa.

Abstract

The combination of mosaic Gag and CAP256 envelope in an HIV vaccine regimen comprising DNA prime and modified vaccinia Ankara (MVA) boost followed by protein boost has previously been shown to generate robust autologous Tier 2 neutralizing antibodies (nAbs) in rabbits. Further refinements of this strategy have been investigated to improve antibody responses. The delivery of both DNA and recombinant MVA vaccines with a needle-free device was compared to delivery by injection, and the effect of formulating the DNA vaccine with adjuvant CpG ODN 1826 was determined. The Pharmajet Stratis^® needle-free injection device (PharmaJet, Golden, CO, USA) improved binding antibody responses to the DNA vaccine as well as both binding and neutralizing antibody responses to the MVA vaccines. Formulation of the DNA vaccines with CpG adjuvant further improved the antibody responses. A shortened vaccination regimen of a single DNA inoculation followed by a single MVA inoculation did not elicit Tier 1B nor Tier 2 neutralization responses as produced by the two DNA, followed by two MVA vaccination regimen. This study showed the immunogenicity of HIV DNA and MVA vaccines administered in a DDMM regimen could be improved using the PharmaJet Stratis needle-free injection device and formulation of the DNA vaccines with CpG adjuvant.

Keywords: CpG; DNA vaccine; HIV vaccine; MVA; PharmaJet Stratis®; needle-free.

Abstract

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