Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2–8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.

We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.

Blastocystis is a protozoan that parasitizes the intestines. A number of hosts of Blastocystis have been found, including human and animals. However, there has been no research on the prevalence of Blastocystis in Tibetan antelope. Here, a molecular test was performed using 627 Tibetan antelope fecal samples collected on Tibet in China from 2019 to 2020. The result showed that 30 (4.8%) samples were Blastocystis positive. The highest prevalence of Blastocystis was in Shuanghu County (25/209, 12.0%), followed by Shenza County (2/103, 1.9%), Nyima County (3/182, 1.6%), and Baigoin County (0/133, 0.0%). In addition, logistic regression analysis showed that the gender, sampling year, and area of Tibetan antelope were risk factors for Blastocystis prevalence. Three subtypes (ST10, ST13, and ST14) of Blastocystis were found in Tibetan antelope through a subtype sequence analysis, and ST13 was identified to be the dominant subtype. This is the first investigation for the infection of Blastocystis in Tibetan antelope. Collectively, the data in this study have expanded the host range of Blastocystis and provided basic information for the distribution of Blastocystis subtypes, which could support the prevention of Blastocystis infection in wild animals.