Adverse Injection Site Reactions Research Articles

Glatiramer acetate persists at the injection site and draining lymph nodes via electrostatically-induced aggregation

Glatiramer acetate (GA) is widely prescribed for the treatment of relapsing-remitting multiple sclerosis, however, the mechanism of action is still not fully understood. We investigated the structural properties of GA and examined alterations to the drug upon injection into the subcutaneous space. First, a variety of biophysical characterization techniques were employed to characterize GA in solution. GA was found to exist as alpha helices in solution with a hydrodynamic radius of ~3 nm in size. To simulate GA behavior at the site of injection, GA was injected into a solution of 1.5 MDa hyaluronic acid (HA). Visible aggregates were observed immediately upon injection and subsequent testing indicated aggregation was driven by electrostatic interactions between the positively-charged GA and negatively-charged HA. In vivo testing confirmed GA formed spherical particles in the nano- to micrometer size range, suggesting this mechanism contributes to persistence at the injection site and in draining lymph nodes. The aggregates were found to associate with glycosaminoglycans, suggesting an electrostatic mechanism of induced aggregation like the simulated injection. These novel observations may help explain the complex immunomodulatory mechanisms of GA and adverse injection site reactions seen in patients.

Immunization with a Recombinant, Pseudomonas fluorescens-Expressed, Mutant Form of Bacillus anthracis-Derived Protective Antigen Protects Rabbits from Anthrax Infection.

Protective antigen (PA), one of the components of the anthrax toxin, is the major component of human anthrax vaccine (Biothrax). Human anthrax vaccines approved in the United States and Europe consist of an alum-adsorbed or precipitated (respectively) supernatant material derived from cultures of toxigenic, non-encapsulated strains of Bacillus anthracis. Approved vaccination schedules in humans with either of these vaccines requires several booster shots and occasionally causes adverse injection site reactions. Mutant derivatives of the protective antigen that will not form the anthrax toxins have been described. We have cloned and expressed both mutant (PA SNKE167-ΔFF-315-E308D) and native PA molecules recombinantly and purified them. In this study, both the mutant and native PA molecules, formulated with alum (Alhydrogel), elicited high titers of anthrax toxin neutralizing anti-PA antibodies in New Zealand White rabbits. Both mutant and native PA vaccine preparations protected rabbits from lethal, aerosolized, B. anthracis spore challenge subsequent to two immunizations at doses of less than 1 μg.

Evaluation of Biocompatibility and Administration Site Reactogenicity of Polyanhydride‐Particle‐Based Platform for Vaccine Delivery

Efficacy, purity, safety, and potency are important attributes of vaccines. Polyanhydride particles represent a novel class of vaccine adjuvants and delivery platforms that have demonstrated the ability to enhance the stability of protein antigens as well as elicit protective immunity against bacterial pathogens. This work aims to elucidate the biocompatibility, inflammatory reactions, and particle effects on mice injected with a 5 mg dose of polyanhydride nanoparticles via common parenteral routes (subcutaneous and intramuscular). Independent of polymer chemistry, nanoparticles more effectively disseminated away from the injection site as compared to microparticles, which exhibited a depot effect. Using fluorescent probes, the in vivo distribution of three formulations of nanoparticles, following subcutaneous administration, indicated migration away from the injection site. Less inflammation was observed at the injection sites of mice-administered nanoparticles as compared to Alum and incomplete Freund's adjuvant. Furthermore, histological evaluation revealed minimal adverse injection site reactions and minimal toxicological effects associated with the administration of nanoparticles at 30 days post-administration. Collectively, these results demonstrate that polyanhydride nanoparticles do not induce inflammation as a cumulative effect of particle persistence or degradation and are, therefore, a viable candidate for a vaccine delivery platform.

Efficacy of novel lipid-formulated whole bacterial cell vaccines against Mycobacterium avium subsp. paratuberculosis in sheep

Mycobacterium avium subsp. paratuberculosis [MAP], the causative agent of enteric Johne's disease, incurs significant economic losses to the livestock industry. Prophylactic vaccination can be employed as a control means, however mineral oil-based vaccines currently in practice have limited efficacy, produce strong antibody responses that confound serological diagnostic testing, and cause severe injection site reactions. In the present study, the safety and efficacy of a commercial mineral oil-adjuvanted vaccine (Gudair™) was compared with novel parenteral-route vaccines in sheep; these comprised live or heat-killed (HK) whole cell preparations of MAP strain 316F, formulated into a food-grade lipid vaccine delivery matrix. Subcutaneous administration of lipid-formulated live or HK 316F-induced significantly fewer adverse injection site reactions than Gudair™; adverse injection site reactions were eliminated altogether by intraperitoneal (i.p.) injection of lipid-formulated live 316F. Injections of lipid-formulated 316F-induced significant peripheral blood cell-mediated immune (CMI) responses in the absence of antibody, while Gudair™-induced strong antibody and CMI reactivity. Vaccinated and non-vaccinated control sheep were challenged via oral inoculation of a virulent MAP isolate, and disease progress was monitored for 16 months, followed by necropsy. All vaccine regimes reduced the overall pathological grading of biopsied intestinal tract (IT) tissues; among these, only Gudair™ promoted a significant reduction in the incidence of histopathological IT lesions, while only i.p. injection of lipid-formulated live 316F significantly reduced the incidence of gross IT lesions. All lipid-formulated vaccines (but not Gudair™) significantly reduced the incidence of bacteriological culture-confirmed MAP infection. This study identifies a new vaccination strategy against Johne's disease in sheep using conventional MAP vaccine strains formulated in a metabolisable lipid delivery matrix.

Use of bovine somatotropin in the tropics: the effect of sometribove on milk production of Bos indicus, dairy crossbred and Bos taurus cows in Zimbabwe

SUMMARYTwenty-four Bos indicus cows of the Mashona/Nkone breeds, 36 dairy crossbreds (Mashona/ Nkone x Friesian), 48 Holsteins, 42 Friesians and 25 Jerseys were used to study the effect on milk production of sometribove (500 mg), a prolonged release formulation of bovine somatotropin (BST). BST was administered at 14-day intervals by subcutaneous injections into the ischio-rectal fossa which lies lateral to and on either side of the anus (tailhead). With the exception of the Bos indicus cows, which received seven injections of BST, all other treated cows received eight.The administration of BST to Bos indicus cows, significantly (P < 0·05) increased milk yield from 0·45 to 1·75 kg/cow per day, and extended lactation. These effects combined to increase total milk production during the 14-week trial from 226 kg for the control group to 993 kg for the group treated with BST. With dairy crossbreds the use of BST significantly (P < 0·01) increased milk yield from 8·6 to 11·0 kg/cow per day. Milk composition for Bos indicus and dairy crossbreds wasunaffected by the administration of BSTBST significantly (P < 0·05) increased milk yield in Jersey (+ 2·9 kg/day), Friesian (+ 3·6 kg/day) and Holstein (+ 2·7 kg/day) cows. Bodycondition of treated cows tended to be slightly lower than that of the control cows at the end of treatment.Cows remained in excellent health throughout all the trials. Farmers commented on how easy the injection was to give in the tailhead site, and on the complete absence of any adverse injection site reaction.