Vaccine testing may have been routine at one time, but not so any more. Because vaccines can be so varied, safety testing programs takes on many forms, from a traditional prophylactic for infectious disease to a novel recombinant vector for treating cancer. There is also an increasing public health push to improve efficacy and minimize the need for revaccination. To ramp up immunity more effectively, vaccines may contain multiple antigens (live or killed viruses, inactivated toxins, or cancer antigens), along with adjuvants that enhance selective and innate immunity. Some novel immune activators have not been in prior trials and require toxicology characterization alongside the full vaccine product. High-risk disease treatments might have mouse-only, accelerated programs, while prophylactic products going into broad populations may require more standard toxicology approaches.
To help sort out the right product and regulatory needs, the Scientific Advisory Services team at Charles River provides guidance on possible accelerations for the appropriate clinical situation and product. Their objective is to provide you, clinicians, and health authorities with adequate information to assess safety for first-in-human studies and also support future changes to the vaccine formulation or licensure.
We consider the novelty and components of the product in addition to prior clinical work on similar agents. Next, we design studies assessing local reactions, systemic toxicity, and in the case of clinical use in women of childbearing potential, any impacts on the fetus or developing infant. These in vivo investigations start with determining the most immunologically relevant animal species, making the selection of the species a key element for the program. Other concerns include whether any autoimmune reactions, limits to species cross reactivity, or off-target sites could trigger pathology. We also consider microbiologic aspects such as BSL containment level and species-selective homing, especially for live-vector components. Immunogenic dose responses and regimen optimization is also a key step in designing the appropriate clinical and nonclinical safety regimen.
Appropriate toxicology strategies should be designed on a case-by-case basis, considering past data with any related vaccines, type of vaccine and degree of novelty, route of administration, clinical population, and human disease risks. At Charles River, we share your concern about getting these vaccines to people in need, and want to work with you to design and perform the best program. This takes a team of specialists with deep experience in immunology, oncology, and vaccine regulation. Please feel free to contact us for more information on how we can help.