Multivalent HIV Vaccine With Boost Enhanced Antibody Responses

Early administration of gp120 Env protein lead to elicitation of binding and neutralizing immune responses in phase 1 study
test tubes in a lab
(Precision Vaccinations News)

Human Immunodeficiency Virus (HIV) vaccine development over the past 35 years has tested several different ideas for vaccines and vaccination regimens. 

Up to now, immunization regimens that have been assessed for the development of HIV vaccines have included purified envelope (Env) protein among the boosting components of the regimen.

A new study published in The Lancet on October 7, 2019, found the ‘co-administration of gp120 Env protein components with DNA or NYVAC vectors during priming, led to early and potent induction of Env V1/V2 IgG binding antibody responses.’

This phase 1 study between August 2012, and April 2013 included 96 participants aged 18–50 years, in a single-center, double-blind, placebo-controlled phase 1b trial in Switzerland.

Study vaccines containing the NYVAC vector were associated with more frequent severe reactogenicity and more adverse events than vaccines containing the DNA vector.

Across the active treatment groups, IgG responses 2 weeks after the 6-month dose of vaccine were 74–95 percent. 

Early administration of gp120 Env protein was associated with a substantially earlier and higher area under the curve for gp120 Env binding, production of anti-V1/V2 and neutralizing antibodies, and better antibody-response coverage over a period of 18 months, compared with vaccination regimens that delayed administration of gp120 Env protein until the 3-month vaccination.

These researchers concluded saying ‘Our data indicate that early administration of gp120 Env protein leads to early elicitation of binding and neutralizing immune responses, with no effect on T-cell responses.’ 

‘The overall area under the IgG binding antibody response curve with early administration of gp120 Env protein is higher and hence, might offer enhanced efficacy as a vaccine regimen.’ 

‘The higher area under the IgG binding antibody response curve is more a result of earlier induction of antibodies and less an outcome of greater durability or overall magnitude of response.’

This study’s discussion included these statements:

  • Previous phase 1/2 clinical studies (the EV01 trial and the EV02 trial) have investigated the immunogenicity of NYVAC vector-based vaccine regimens in homologous or heterologous DNA vector-based priming and NYVAC vector-based boost combinations. 
  • In these studies, responses and magnitudes of responses for both CD4 and CD8 T cells were greatly increased in the regimens with a DNA vector-based prime and a NYVAC vector-based boost. 
  • It is important to underscore that both the NYVAC and DNA vector-based vaccines used in the EV02 trial and another trial (EV03) were different from those used in HVTN 096 with respect to the clade C subtype, the number of NYVAC vectors and DNA vectors used, and the optimization of HIV immunogen expression. 
  • The immunogenicity results obtained in HVTN 096 are highly consistent with those obtained in the EV01 trial and EV02 trial and indicate that, in study groups not containing proteins in the prime (T1 and T3), peak responses and magnitudes of response occurred 2 weeks after the month 3 vaccination for CD4 T cells and 2 weeks after the month 6 vaccination for CD8 T cells. CD4 T-cell responses were durable and remained unchanged in both responses and magnitudes of response by 6 months after the month 6 vaccination. 
  • These results, therefore, further confirm the superiority of heterologous prime and boost DNA and NYVAC vector-based regimens compared with homologous prime and boost NYVAC vector-based regimens.

HIV disease continues to be a serious health issue for parts of the world. Worldwide, there were about 1.8 million new cases of HIV in 2017.

During 2017, 38,739 people received an HIV diagnosis in the USA and dependent areas. The annual number of new diagnoses declined by 9 percent from 2010 to 2016 in the USA, reports the Centers for Disease Control and Prevention (CDC).

An estimated 1.1 million people in the USA had HIV at the end of 2016, the most recent year for which this information is available. Of those people, about 14 percent did not know they had HIV, says the CDC.

This study’s funding was from the National Institutes of Health, National Institute of Allergy and Infectious Diseases, and the Bill & Melinda Gates Foundation. These researchers disclosed various industry relationships.

HIV Vaccine information published by Precision Vaccinations


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