Adjuvants such as the aluminum compounds (alum) have been dominantly used in many vaccines due to their immunopotentiation and safety records since 1920s. However, how these mineral agents influence the immune response to vaccination remains elusive. Many hypotheses exist as to the mode of action of these adjuvants, such as depot formation, antigen (Ag) targeting, and the induction of inflammation. These hypotheses are based on many in vitro and few in vivo studies. Understanding how cells interact with adjuvants in vivo will be crucial to fully understanding the mechanisms of action of these adjuvants. Interestingly, how alum influences the target cell at both the cellular and molecular level, and the consequent innate and adaptive responses, will be critical in the rational design of effective vaccines against many diseases. Thus, in this review, mechanisms of action of alum have been discussed based on available in vitro vs in vivo evidences to date.

Aluminium adjuvants (alum) have been the only widely approved adjuvants for use in human vaccines since the 1920s, however, the mechanism of action of these adjuvants remains elusive. Due to increasing demand for novel adjuvants, a clearer understanding of the mechanisms that allow these important agents to affect adaptive immune responses will make a significant contribution to the rational design of future vaccines. Using a novel approach to tracking antigen and antigen presentation, we demonstrate that alum induces higher antigen accumulation and increased antigen presentation by dendritic cells (DCs) in vitro. Antigen accumulation was 100-fold higher and antigen presentation 10-fold higher following alum treatment when compared with soluble protein alone. We also observed that alum causes an initial reduction in presentation compared with soluble antigen, but eventually increases the magnitude and duration of antigen presentation. This was associated with reduced protein degradation in DCs following alum treatment. These studies demonstrate the dynamic alterations in antigen processing and presentation induced by alum that underlie enhanced DC function in response to this adjuvant.

Rabies is a vaccine-preventable fatal viral disease that is zoonotic in nature. In this article, we provide a justification why the agreement of the World Health Organization (WHO), the Food and Agriculture Organization (FAO), the World Organization for Animal Health (OIE), and Global Alliance for Rabies Control (GARC) on The Global Strategic Plan to End Human Deaths from Dog-mediated Rabies by 2030 should also include a more holistic approach and ecologic views.

Introduction: Cats (Felis catus) are the only felines that live in close contact with humans. Since cats can act as vectors, carriers, reservoirs and definitive hosts of many gastrointestinal (GI) parasites, parasitic assessment could contribute to their survival and well‐being.Aims: The current study aimed to assess the diversity and prevalence of GI parasites in domestic and feral cats from Ratnanagar in Chitwan in Central Nepal.Methods: A total of 107 fresh faecal samples of cats (90 household cats and 17 feral cats) of varied ages and sex were collected and transported to the laboratory. The copromicroscopic examination was carried out following direct wet mount, formalin‐ethyl acetate sedimentation, saturated salt flotation, acid‐fast staining and sporulation techniques. Furthermore, associated risk factors were evaluated to ascertain the predictor of risks for parasitic acquisition.Results: The current study revealed an overall 95.3% prevalence rate with a 100% rate in feral cats and 94.4% in household cats. Altogether, 18 (17 known and one unknown) different species of GI parasites were reported with the helminths (95.3%; 11 species) and the protozoa (55.1%; seven species). Besides age and sex, outdoor lifestyle, absence or unknown history of medication and hunting behaviour of the felines are the predictors of risk. Furthermore, mixed infection was comparatively higher than single infection in the faecal samples.Conclusions: Cats harbour a higher prevalence and greater diversity of GI parasites, and parasitism varies with age and sex. This finding can be essential for veterinarians and public health authorities for strategic treatment and for assessing the zoonotic transmission of the parasites from these felines. Importantly, an effective medication strategy for cats and owners is recommended.