Prospects for development of a vaccine to prevent and control vaginal candidiasis

Abstract

A vaccine against recurrent vulvovaginal candidiasis (RVVC) would benefit a large number of women who suffer from this debilitating syndrome. To date, several antigen formulations have been tested with modest results. In this article, we review the latest vaccine study reported in the literature. The candidate is a β-glucan conjugate administered with a human compatible adjuvant. Results in a mouse model of vaginitis were again modest for protection. However, the study included live animal imaging to quantify fungal burden; animals were challenged with a Candida strain carrying a gene encoding a glycophosphatidylinositol (GPI)-linked cell wall protein and luciferase. Fungal burden was expressed as photons following substrate administration. Protection appeared to be mediated by β-glucan antibodies. Although modest protection was observed, the imaging system was less variable than semi-quantitative plate counts of vaginal lavage fluid. Despite these advances in evaluating protection, a vaccine candidate against RVVC worthy of clinical testing remains elusive.

Fig. 1

In vivo imaging of vaccinated mice vaginally inoculated with Candida albicans cells expressing gLUC. Mice previously treated with adjuvant (MF59) or vaccinated with adjuvant plus Lam-CRM (M59+LAM), under pseudoestrus conditions, were inoculated for 2 consecutive days with 10 μL of a 10⁹ cell/mL suspension of C. albicans cell expressing gLUC into the vaginal lumen. After 4, 7, 11, and 13 days, post-inoculation mice were treated intravaginally with 10 μg of coelenterazine and imaged in the IVIS-200 imaging system under 2.5% isoflurane anesthesia. (From Pietrella et al. [43••], with permission from Elsevier.)