the goal this clinical trail is to evaluate the safety、Pharmacokinetic and immunogenicity of GR2102 injection。 Subjects will be enrolled in different groups in sequential order, and within each group will be randomly assigned to receive either GR2102 injection or placebo administration, with each Subjects will be enrolled in only one of these groups。

This is a randomized, double-blind, placebo-controlled, single-dose administration study to evaluate the safety, tolerability, pharmacokinetics, and preliminary pharmacodynamic profile of GR2102 Injection in healthy adult Chinese subjects.

After signing the informed consent form, subjects who meet the criteria for enrollment will be entered into different groups according to the randomization number.Subjects will be enrolled in only one of these groups.

Only after the 8 subjects in the current group have completed at least 7 days of safety and tolerability observations and have been determined to be safe and tolerable, will another group of subjects be allowed to proceed to the next group .

After completion of dosing, follow-up will be at least 150 days.

Inclusion Criteria:

1. Healthy adult subjects
2. Signed informed consent

Exclusion Criteria:

1. Signs and symptoms of upper respiratory tract infection prior to randomization
2. Prior use of RSV vaccine or RSV antibody-based medications
3. history of malignant tumor