This is a phase 1 study in which healthy adult volunteers will receive BRII-198 or placebo and will be assessed for safety, tolerability, and pharmacokinetics.

Inclusion Criteria:

• Subject must be 18 to 49 years of age inclusive;
• Body weight ≤100 kg and body mass index (BMI) within the range of 19.0-24.0kg/m2 (inclusive);
• Male or female;

Exclusion Criteria:

• Any clinically significant chronic or acute medical condition that makes the volunteer unsuitable for participation;
• A history of significant hypersensitivity, intolerance, or allergy to any drug compound;
• History of alcohol or other substance abuse;