**4. Model suitable for vaccine trials**

The question of whether or not there should be a standardized model is the basis on which the current controversies in HIV research rest on [26]. Differences in SIV and SHIV replication in the rhesus macaque, cynomolgous and pigtailed macaques' species have been observed and is favored in the design of experimental models depending on the question raised [40]. For vaccine research, the rhesus does present the ideal for pathogenesis research; however, demanding for its use as a standard does present problems the current wave is to base considerations on the transgenic mice models. Besides, vaccine testing in more than one species of macaques with similar vaccine modalities provides an opportunity to compare outcomes thus increasing confidence of research reproducibility [79].

Regulatory authorities require vaccine candidates to undergo preclinical evaluation in animal models before they enter the clinical trials in humans [80]. The overarching goal of a new vaccine is to stimulate the immune system to elicit an effective immune response against the pathogen it has been designed for, and currently no alternatives to live animal use currently exist for evaluation of this response despite advances in computational sciences for the search of an *in-silico* model [80].

Integral studies such as elucidation of immune protection mechanism, optimizing route and constitutions of vaccines; determining the onset and duration of immunity, as well as satisfying safety and efficacy requirements of the new vaccines, must be done in an integrated living system [80]. As discussed earlier, a standardized animal model that provides all the information required for advancing a new vaccine through the preclinical stage has still not been met and even if it were, it is still bereft with problems bordering on bioethics. Current trend suggests that humanized mice (**Table 3**) more accurately predict vaccine outcomes that approximate humans.

of HIV. In one of the earliest experiments on the subject(macaques) [73], an animal model for the heterosexual transmission of HIV was developed by applying SIV onto the genital mucosa of both mature and immature male and female rhesus macaques. The study suggests that in the genital tract, the mucous membrane acts as a barricade to SIV infections as well as the non-involvement

Experimental Animal Models of HIV/AIDS for Vaccine Trials

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Recent animal model research has focused on: (1) refinement of existing models and the development of new ones; (2) development of a model in response to latency especially HIV reservoir and immune perseverance and (3) evaluation of vaccine candidate that would elicit broadly neutralizing antibodies. As discussed in the chapter, a suitable and cost-effective animal model for HIV has been a goal spanning three decades with important milestones accomplished.

\* and Efejiro Ashano<sup>2</sup>

1 Laboratory of Animal Models for Human Diseases, Medical Biotechnology Department,

2 Immunovirology and Vaccine Development Laboratory (IVL), Medical Biotechnology

[1] Haigwood NL. Update on animal models for HIV research. European Journal of Immu-

[2] Sharma B. Exploring experimental animal models in HIV/AIDS research. Biochemistry

[3] Sharma B. Anti-HIV-1 drug toxicity and management strategies. Neurobehavioural HIV

[4] Hartman TL, Buckheit RW. The continuing evolution of HIV-1 therapy: Identification and development of novel antiretroviral agents targeting viral and cellular targets.

[5] Saayman S, Barichievy S, Capovilla A, Morris KV, Arbuthnot P, Weinberg MS. The efficacy of generating three independent anti-HIV-1 siRNAs from a single U6 RNA pol III-

[6] Hatziioannou T, Evans DT. Animal models for HIV/AIDS research. Nature Reviews

Department, National Biotechnology Development Agency, Abuja, Nigeria

of spermatozoa and seminal plasma for genital HIV transmission.

\*Address all correspondence to: barthokeyibeh@yahoo.com

National Biotechnology Development Agency, Abuja, Nigeria

and Analytical Biochemistry. 2013;**2**(129):1009-2161

Molecular Biology International. 2012;**2012**:401965, 17 p

expressed long hairpin RNA. PLoS One. 2008;**3**(7):e2602

**Author details**

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