Human cord derived MSC cell(Beijing First Biotechnology)

Primary objective: To evaluate the short-term safety and tolerability of human umbilical cord mesenchymal stem cell injection in patients with moderate to severe allergic rhinitis, and to recommend appropriate dosage for future studies. Secondary objective: To evaluate the long-term safety, immunogenicity, and preliminary efficacy of human umbilical cord mesenchymal stem cell injection in patients with moderate to severe allergic rhinitis.