There is an urgent need for a broad-spectrum and protective vaccine due to the emergence and rapid spreading of more contagious SARS-CoV-2 strains. We report the development of RBMRNA-176, a pseudouridine (Ψ) nucleoside-modified mRNA-LNP vaccine encoding pre-fusion stabilized trimeric SARS-CoV-2 spike protein ectodomain, and evaluate its immunogenicity and protection against virus challenge in mice and nonhuman primates. A prime-boost immunization with RBMRNA-176 at intervals of 21 days resulted in high IgG titers (over 1:819,000 endpoint dilution) and a CD4+ Th1-biased immune response in mice. RBMRNA-176 vaccination induced pseudovirus-neutralizing antibodies with IC50 ranging from 1:1020 to 1:2894 against SARS-CoV-2 spike pseudotyped wild-type and variant viruses, including Alpha, Beta, Gamma, and Kappa. Moreover, significant control of viral replication and histopathology in lungs was observed in vaccinated mice. In nonhuman primates, a boost given by RBMRNA-176 on day 21 after the prime induced a persistent and sustained IgG response. RBMRNA-176 vaccination also protected macaques against upper and lower respiratory tract infection, as well as lung injury. Altogether, these findings support RBMRNA-176 as a vaccine candidate for prevention of COVID-19.

Introduction. Forsythin is the main ingredient of Forsythia suspensa and is widely used in treatment of fever, viral cold, gonorrhea, and ulcers clinically. This study aimed to evaluate the potential genetic toxicity of forsythin and its safety for human use. Methods. Based on the Good Laboratory Practice regulations and test guidelines, the genetic toxicity of forsythin was assessed by the Ames test, chromosome aberration (CA) test, and bone marrow micronucleus (MN) test in vivo. In the Ames test, five strains of Salmonella typhimurium were exposed to different concentrations of forsythin in the presence or absence of the S9 mixture, and then, the number of His + revertant colonies was counted. In the CA test, Chinese hamster lung (CHL) fibroblast cells were treated with different concentrations of forsythin, mitomycin C, or cyclophosphamide in the presence or absence of the S9 mixture, and the chromosomal aberrations were determined. In the MN test, bone marrow was isolated from the mice with different treatments, and the ratios of polychromatic erythrocytes (PCE) and erythrocytes (PCE/(PCE + NCE)) were measured. Finally, beagle dogs were divided into four groups (negative control, low dose, medium dose, and high dose groups), and then, a telemetry system was used to evaluate the safe use of forsythin. Results. Ames test results showed that the number of colonies in all test strains with different treatments showed no significantly dose-dependent increase in the presence or absence of the S9 mixture ( p > 0.05 ). In the CA test, the number of cells with aberrations in the CHL fibroblast cells treated with low, medium, and high doses of forsythin for 24/48 h in the absence of the S9 mixture was, respectively, 5.0/2.5, 4.5/1.5, and 5.0/5.0, and in the presence of the S9 mixture, the number was, respectively, 5.0, 5.0, and 4.5. These results showed that there was no significant difference compared to the negative control group either in the presence (2.0) or in the absence (4.0/2.5 for 24/48 h) of the S9 mixture ( p > 0.05 ). The MN test showed that the values of PCE/(PCE + NCE) in the negative, positive controls, and forsythin treatment groups were all more than 20%, which indicated that forsythin had no cytotoxicity. Additionally, no significant toxicological effects of forsythin on blood pressure, respiration, temperature, electrocardiogram, and other physiological indicators in the conscious beagle dogs of different groups were observed by the telemetry method. Conclusion. Our findings showed that forsythin has low probability of genetic toxicity and no significant toxicological effects, which implied that forsythin is suitable for further development and potential application.

Purpose: To further evaluate the safety of Fuganlin Oral Liquid (FGLOL) for clinical application by conducting toxicological tests in young rats. Methods: Based on the clinical dose for infants aged less than 1 year, 4-day-old Sprague-Dawley (SD) rats were orally administered FGLOL3.88, 11.64 and 38.75 g crude drug/kg for 18 days, followed by a 3-week withdrawal. This was followed by evaluating the effect of FGLOL on various growth and development indicators, nerve reflex function and spontaneous behavior of the rats. Based on the clinical dose for children aged 1 - 6 years, 15-day-old rats were orally administered FGLOL3.88, 11.64 and 38.75 g crude drug/kg for 31 days, followed by a 3-week withdrawal in order to evaluate the impact of the FGLOL on the development of reproductive organs and nervous systems in young rats. The effects of FGLOL on the safety of young rats were judged based on ophthalmic examination, physical examination, spontaneous behavior and other developmental effects. Results: FGLOL did not cause animal death, and no significant toxicological changes were observed in the body weight, growth and development, and behavior of the young rats (p < 0.05). No observed adverse effect level (NOAEL) even after administering the higher dose at each stage. However, the results at each stage showed that oral administration of a large amount of FGLOL had a greater effect on normal food consumption of the rats (p < 0.05). Conclusion: The findings indicate that Fuganlin Oral Liquid, a traditional Chinese medicine formulation, is safe in rats. However, clinical trials are required to acertain its safety in humans.

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The safety comparisons between APZ001 antibody and Erbitux showed that these two antibodies showed highly similarities in mice, rabbits and cynomolgus monkey animal models in consideration of pharmaceutical effects, indicating APZ001 might be a suitable substitute for Erbitux.