Favorable Nonclinical Safety Profile of RSVpreF Bivalent Vaccine in Rats and Rabbits.

: Respiratory syncytial virus (RSV) infections usually cause mild, cold-like symptoms in most people, but are a leading infectious disease causing infant death and hospitalization and can result in increased morbidity and mortality in older adults and at-risk individuals. Pfizer has developed Abrysvo, an unadjuvanted bivalent recombinant protein subunit vaccine containing prefusion-stabilized fusion (F) proteins representing RSV A and RSV B subgroups (RSVpreF). It is the only RSV vaccine approved for both maternal immunization to protect infants and active immunization of older adults (≥60 years) and 18-59-year-old individuals with high-risk conditions for prevention of RSV disease.

Photothrombolytics: A light-driven technology for the targeted lysis of thrombi.

Occlusive blood clots remain a significant global health challenge and result in emergencies that are main causes of death and disability worldwide. Thrombolytic agents (including tissue plasminogen activator, tPA) are the only pharmacological means to dissolve blood clots. However, these drugs have modest efficacy and severe safety concerns persist.

Session 4: mRNA and Self-Amplifying RNA (saRNA): Opportunities for Disease Prevention and Therapy.

The unprecedented speed of developing vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has propelled mRNA technologies into the public eye. The versatility of mRNA technology, often referred to as "plug and play," offers immense promise for rapidly updating vaccines to address newer variants of respiratory diseases and combat emerging infectious diseases and lethal pathogens, such as the Ebolavirus. However, the potential applications of mRNA technology extend well beyond prophylactic vaccines.

Next-Generation Contraceptive Intravaginal Ring: Comparison of Etonogestrel and Ethinyl Estradiol In Vitro and In Vivo Release from 3D-Printed Intravaginal Ring and NuvaRing.

Intravaginal rings (IVRs) represent a well-established, woman-controlled and sustained vaginal drug delivery system suitable for a wide range of applications. Here, we sought to investigate the differences in etonogestrel (ENG) and ethinyl estradiol (EE) release from a 3D-printed IVR utilizing continuous liquid interface production (CLIP™) (referred to as CLIP for low drug loading and CLIP IVRs for high drug loading) and NuvaRing, a commercially available injection molded IVR. We conducted in vitro release studies in simulated vaginal fluid to compare the release of ENG and EE from CLIP IVRs and NuvaRing.

Instantly adhesive and ultra-elastic patches for dynamic organ and wound repair.

Bioadhesive materials and patches are promising alternatives to surgical sutures and staples. However, many existing bioadhesives do not meet the functional requirements of current surgical procedures and interventions. Here, we present a translational patch material that exhibits instant adhesion to tissues (2.

NRF2 Activation in Trp53;p16-deficient Mice Drives Oral Squamous Cell Carcinoma.

Unlabelled: Aberrant activation of the NRF2/NFE2L2 transcription factor commonly occurs in head and neck squamous cell carcinomas (HNSCC). Mouse model studies have shown that NRF2 activation alone does not result in cancer. When combined with classic oncogenes and at the right dose, NRF2 activation promotes tumor initiation and progression.

Next generation 3D-printed intravaginal ring for prevention of HIV and unintended pregnancy.

Globally, there are 20 million adolescent girls and young women living with HIV who have limited access to long-acting, effective, women-controlled preventative methods. Additionally, although there are many contraceptive methods available, globally, half of all pregnancies remain unintended. Here we report the first 3D-printed multipurpose prevention technology (MPT) intravaginal ring (IVR) for HIV prevention and contraception.

Toxicologic Pathology Forum: Tissue Evaluation in Nonclinical Toxicity Studies for Prophylactic Vaccines.

Nonclinical toxicity testing (GLP) of prophylactic vaccines to support human clinical trials is outlined in the World Health Organization nonclinical vaccine-development guidelines, which are followed by most regulatory agencies globally. Vaccine GLP toxicity studies include at least two groups: a buffer control (often phosphate-buffered saline) group and a highest anticipated clinical dose formulation group. However, studies may include additional groups, including lower-dose formulation groups and adjuvant-containing formulation control groups.

Ocular Safety and Toxicokinetics of Bevacizumab-bvzr (Zirabev), a Bevacizumab Biosimilar, Administered to Cynomolgus Monkeys by Intravitreal Injection.

Bevacizumab-bvzr (Zirabev), a recombinant humanized monoclonal antibody targeting vascular endothelial growth factor and a biosimilar to bevacizumab, is approved for intravenous administration for various indications worldwide. The objectives of this study were to evaluate the ocular toxicity, systemic tolerability, and toxicokinetics (TKs) of bevacizumab-bvzr following repeat intravitreal (IVT) injection to cynomolgus monkeys. Male monkeys were administered saline, vehicle, or bevacizumab-bvzr at 1.

Toxicological Assessments of a Pandemic COVID-19 Vaccine-Demonstrating the Suitability of a Platform Approach for mRNA Vaccines.

The emergence of SARS-CoV-2 at the end of 2019 required the swift development of a vaccine to address the pandemic. Nonclinical GLP-compliant studies in Wistar Han rats were initiated to assess the local tolerance, systemic toxicity, and immune response to four mRNA vaccine candidates encoding immunogens derived from the spike (S) glycoprotein of SARS-CoV-2, encapsulated in lipid nanoparticles (LNPs). Vaccine candidates were administered intramuscularly once weekly for three doses at 30 and/or 100 µg followed by a 3-week recovery period.

Modeling SARS-CoV-2: Comparative Pathology in Rhesus Macaque and Golden Syrian Hamster Models.

Coronavirus disease 2019 (COVID-19) in humans has a wide range of presentations, ranging from asymptomatic or mild symptoms to severe illness. Suitable animal models mimicking varying degrees of clinical disease manifestations could expedite development of therapeutics and vaccines for COVID-19. Here we demonstrate that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulted in subclinical disease in rhesus macaques with mild pneumonia and clinical disease in Syrian hamsters with severe pneumonia.

Lack of effects on female fertility and prenatal and postnatal offspring development in rats with BNT162b2, a mRNA-based COVID-19 vaccine.

BNT162b2 is a vaccine developed to prevent coronavirus disease 2019 (COVID-19). BNT162b2 is a lipid nanoparticle formulated nucleoside-modified messenger RNA (mRNA) encoding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein locked in its prefusion conformation. A developmental and reproductive toxicity study was conducted in rats according to international regulatory guidelines.

BNT162b vaccines protect rhesus macaques from SARS-CoV-2.

A safe and effective vaccine against COVID-19 is urgently needed in quantities that are sufficient to immunize large populations. Here we report the preclinical development of two vaccine candidates (BNT162b1 and BNT162b2) that contain nucleoside-modified messenger RNA that encodes immunogens derived from the spike glycoprotein (S) of SARS-CoV-2, formulated in lipid nanoparticles. BNT162b1 encodes a soluble, secreted trimerized receptor-binding domain (known as the RBD-foldon).

Evaluation of Rat Acute Phase Proteins as Inflammatory Biomarkers for Vaccine Nonclinical Safety Studies.

The objectives were to characterize the kinetics of acute phase proteins (APPs) α-2 macroglobulin (A2M), α-1 acid glycoprotein (A1AGP), and fibrinogen (FIB), and injection site macroscopic and microscopic findings following intramuscular administration of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (TDaP; Adacel); adjuvants (aluminum phosphate [AlPO]; aluminum hydroxide, Al[OH]; CpG/Al[OH]; or Quillaja saponaria 21 [QS-21]); or saline to female Wistar Han rats. Intravascular lipopolysaccharide (LPS) was a positive control. Injection sites and lymph nodes were evaluated microscopically, using hematoxylin and eosin (H&E) stained sections, 48 hours postdose (HPD) and compared with APP concentrations; A2M and A1AGP were measured using Meso Scale Discovery analyzer.

Review of Current Vaccine Development Strategies to Prevent Coronavirus Disease 2019 (COVID-19).

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak that started in Wuhan, China, in 2019 resulted in a pandemic not seen for a century, and there is an urgent need to develop safe and efficacious vaccines. The scientific community has made tremendous efforts to understand the disease, and unparalleled efforts are ongoing to develop vaccines and treatments. Toxicologists and pathologists are involved in these efforts to test the efficacy and safety of vaccine candidates.

Lipid mass spectrometry imaging and proteomic analysis of severe aortic stenosis.

Severe aortic stenosis (AS) is prevalent in adults ≥ 65 years, a significant cause of morbidity and mortality, with no medical therapy. Lipid and proteomic alterations of human AS tissue were determined using mass spectrometry imaging (MSI) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) to understand histopathology, potential biomarkers of disease, and progression from non-calcified to calcified phenotype. A reproducible MSI method was developed using healthy murine aortic valves (n = 3) and subsequently applied to human AS (n = 2).

Scientific and Regulatory Policy Committee Points to Consider*: Approaches to the Conduct and Interpretation of Vaccine Safety Studies for Clinical and Anatomic Pathologists.

The design and execution of toxicology studies supporting vaccine development have some unique considerations relative to those supporting traditional small molecules and biologics. A working group of the Society of Toxicologic Pathology Scientific and Regulatory Policy Committee conducted a review of the scientific, technical, and regulatory considerations for veterinary pathologists and toxicologists related to the design and evaluation of regulatory toxicology studies supporting vaccine clinical trials. Much of the information in this document focuses on the development of prophylactic vaccines for infectious agents.

Immune Relevant and Immune Deficient Mice: Options and Opportunities in Translational Research.

In 1989 ILAR published a list and description of immunodeficient rodents used in research. Since then, advances in understanding of molecular mechanisms; recognition of genetic, epigenetic microbial, and other influences on immunity; and capabilities in manipulating genomes and microbiomes have increased options and opportunities for selecting mice and designing studies to answer important mechanistic and therapeutic questions. Despite numerous scientific breakthroughs that have benefitted from research in mice, there is debate about the relevance and predictive or translational value of research in mice.

Phenotypic Modulation of Skeletal Muscle Fibers in LPIN1-Deficient Lipodystrophic ( fld) Mice.

Lipin-1 ( Lpin1)-deficient lipodystrophic mice have scant and immature adipocytes and develop transient fatty liver early in life. Unlike normal mice, these mice cannot rely on stored triglycerides to generate adenosine triphosphate (ATP) from the β-oxidation of fatty acids during periods of fasting. To compensate, these mice store much higher amounts of glycogen in skeletal muscle and liver than wild-type mice in order to support energy needs during periods of fasting.

High post-natal mortality associated with defects in lung maturation and reduced adiposity in mice with gestational exposure to high fat and N-acetylcysteine.

Studies have demonstrated that maternal consumption of a high fat diet (HFD) increases offspring susceptibility to metabolic disease. This study was initiated to identify the mechanistic contribution of oxidative stress on this phenomenon. Two weeks prior to mating, dams were fed either HFD or Control diet with or without supplementation with the anti-oxidant N-acetylcysteine (NAC).

Inflammatory Cell Findings in the Female Rabbit Heart and Stress-associated Exacerbation with Handling and Procedures Used in Nonclinical Studies.

Despite the use of rabbits in biomedical research, including regulatory toxicology and cardiovascular studies, little data exist on heart findings in this species. This study was designed to document myocardial findings in female rabbits and the impact of study-related procedures typical for vaccine toxicology studies. One hundred and forty 6- to 8-month-old female New Zealand White rabbits were divided equally into 2 groups, high and low study procedure groups (group 1 and group 2, respectively).

Translating Mouse Models.

Mice and humans branched from a common ancestor approximately 80 million years ago. Despite this, mice are routinely utilized as animal models of human disease and in drug development because they are inexpensive, easy to handle, and relatively straightforward to genetically manipulate. While this has led to breakthroughs in the understanding of genotype-phenotype relationships and in the identification of therapeutic targets, translation of beneficial responses to therapeutics from mice to humans has not always been successful.

LPA receptor activity is basal specific and coincident with early pregnancy and involution during mammary gland postnatal development.

During pregnancy, luminal and basal epithelial cells of the adult mammary gland proliferate and differentiate resulting in remodeling of the adult gland. While pathways that control this process have been characterized in the gland as a whole, the contribution of specific cell subtypes, in particular the basal compartment, remains largely unknown. Basal cells provide structural and contractile support, however they also orchestrate the communication between the stroma and the luminal compartment at all developmental stages.

IMP1, an mRNA binding protein that reduces the metastatic potential of breast cancer in a mouse model.

Cells that are able to localize β-actin mRNA efficiently have decreased metastatic potential. Invasive carcinoma cells derived from primary mammary tumors have reduced levels of an RNA binding protein IMP1/ZBP1/IGF2BP1, required for β-actin mRNA localization. We showed previously that in human breast carcinoma cells in vitro, this protein suppresses invasion.