Vaccines: Correlates of Vaccine‐Induced Immunity
ABSTRACT The immune system is redundant, and B and T cells collaborate. However, almost all current vaccines work through induction of antibodies in serum or on mucosa that block infection or interfere with microbial invasion of the bloodstream. To protect, antibodies must be functional in the sense of neutralization or opsonophagocytosis. Correlates of protection after vaccination are sometimes absolute quantities but often are relative, such that most infections are prevented at a particular level of response but some will occur above that level because of a large challenge dose or deficient host factors. There may be >1 correlate of protection for a disease, which we term "cocorrelates." Either effector or central memory may correlate with protection. Cell-mediated immunity also may operate as a correlate or cocorrelate of protection against disease, rather than against infection. In situations where the true correlate of protection is unknown or difficult to measure, surrogate tests (usually antibody measurements) must suffice as predictors of protection by vaccines. Examples of each circumstance are given.
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- "Hence cytokine profiling for immunological monitoring of T-cell responses are best studied by stimulating Tcells in vitro in an antigen specific manner and then analysing the patterns of cytokine induction at mRNA or protein level using various assays, so called antigen-specific cytokine responses. The antigen-specific cytokine response is likely to be an important part of vaccine assessment    and can be used to monitor immune status of animals during disease progression or following vaccination. "
ABSTRACT: The interest in analysing antigen-specific cytokine responses has substantially increased in recent years, in part due to their use in assessing vaccine efficacy. In the present study, the kinetics of IL-2, IL-4 and IFN-γ expression was determined in bovine PBMCs by real-time PCR and in whole blood by cytokine-release assay after in vitro stimulation with recall foot-and-mouth disease virus (FMDV) antigen. The results showed that the cytokine mRNA of IL-2 and IFN-γ in PBMCs were induced early (peak induction at 6 h), whereas the IL-4 mRNA showed delayed induction (peaked at 24 h). In contrast, the kinetics of cytokine proteins in whole blood was different and required the accumulation of the proteins before being optimally detected. The peak accumulation of cytokine protein in whole blood was recorded at 72 h for IL-2 and IL-4, and 96 h for IFN-γ. The findings of this study are of importance when selecting an optimal time points for measuring antigen-specific cytokine expression in cattle.Cytokine 03/2015; 72(1):58–62. DOI:10.1016/j.cyto.2014.12.011 · 2.66 Impact Factor
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- "Only 50% of the vaccinated cats strongly neutralised the pseudotype bearing KKS Env, the sequence of which closely resembles that of FIV-Petaluma , one component of the divalent FIV vaccine . A strong NAb response had been proposed as a correlate of protection   and a crucial component of humoral immunity against virus infections  . Initial studies reported that NAbs recognising the homologous Petaluma and Shizuoka strains were detected in most vaccinated cats and eight of twelve vaccinated cats neutralised the heterologous FIV Bangston isolate, leading to the conclusion that the two isolates of FIV within the vaccine might act synergistically to enhance the development of NAbs against heterologous strains of FIV . "
ABSTRACT: Across human and veterinary medicine, vaccines against only two retroviral infections have been brought to market successfully, the vaccines against feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). FeLV vaccines have been a global success story, reducing virus prevalence in countries where uptake is high. In contrast, the more recent FIV vaccine was introduced in 2002 and the degree of protection afforded in the field remains to be established. However, given the similarities between FIV and HIV, field studies of FIV vaccine efficacy are likely to advise and inform the development of future approaches to HIV vaccination. Here we assessed the neutralising antibody response induced by FIV vaccination against a panel of FIV isolates, by testing blood samples collected from client-owned vaccinated Australian cats. We examined the molecular and phenotypic properties of 24 envs isolated from one vaccinated cat that we speculated might have become infected following natural exposure to FIV. Cats vaccinated against FIV did not display broadly neutralising antibodies, suggesting that protection may not extend to some virulent recombinant strains of FIV circulating in Australia. Copyright © 2015. Published by Elsevier Ltd.Vaccine 01/2015; 11(8). DOI:10.1016/j.vaccine.2015.01.028 · 3.62 Impact Factor
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- "coincides with the detection of cross-neutralizing antibodies in the serum and cervicovaginal secretions of vaccinees [10,17–20]. Such antibodies may be effectors, or their detection may have utility as a correlate or surrogate of vaccine-induced cross-protection . The development of potential next generation vaccines to improve the breadth of genotype coverage   is based upon two approaches: improving the immunogenicity of a conserved region of the minor capsid protein (L2) to generate broadly neutralizing antibodies , and using a multivalent L1 VLP-based vaccine that induces type-specific antibodies against a wider array of HPV genotypes (HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, HPV58; V503, Merck Research Laboratories). "
ABSTRACT: Human papillomavirus (HPV) vaccines confer protection against the oncogenic genotypes HPV16 and HPV18 through the generation of type-specific neutralizing antibodies raised against the constituent virus-like particles (VLP) based upon the major capsid proteins (L1) of these genotypes. The vaccines also confer a degree of cross-protection against some genetically related types from the Alpha-9 (HPV16-like: HPV31, HPV33, HPV35, HPV52, HPV58) and Alpha-7 (HPV18-like: HPV39, HPV45, HPV59, HPV68) species groups. The mechanism of cross-protection is unclear but may involve antibodies capable of recognizing shared inter-genotype epitopes. The relationship(s) between the genetic and antigenic diversity of the L1 protein, particularly for non-vaccine genotypes, is poorly understood.Vaccine 09/2014; 32(48). DOI:10.1016/j.vaccine.2014.07.116 · 3.62 Impact Factor