This is a randomized, double-blind, placebo-controlled Phase 1 study in participants over the age of 18 years with mild to moderate COVID-19. This study aims to assess the safety, tolerability and preliminary antiviral effect of HH-120. This study includes dose escalation phase and dose expansion phase.

Inclusion Criteria:

• The escalation phase:

  1. Participants are aged 18 to 65 years (inclusive at the time of informed consent)
  2. Participants are mild or moderate COVID-19 patients.
  3. Participants have one or more mild or moderate COVID 19-related symptoms as defined by the FDA (see the Diagnosis and Main Criteria for Inclusion) with the onset of symptoms ≤ 3 days prior to the randomization.

• The expansion phase:

  1. Participants are ≥18 years of age at the time of randomization.
  2. Participants are mild or moderate COVID-19 patients.
  3. Participants have one or more mild or moderate COVID 19-related symptoms as defined by the FDA (see the Diagnosis and Main Criteria for Inclusion) with the onset of symptoms ≤ 5 days prior to the randomization.

Exclusion Criteria:

• Pregnant or lactating at Screening or planning to become pregnant (self or partner) at any time during the study, including the follow-up period.
• Prior or ongoing medical conditions, medical history, physical findings, or laboratory abnormality that, in the PI's (or delegate's) opinion, could adversely affect the safety of the participant or that might interfere with the conduct of the study.
• Presence of any underlying physical or psychological medical condition that, in the opinion of the PI, would make it unlikely that the participant will comply with the protocol or complete the study per protocol.
• Have known allergies to any of the components used in the formulation of the study intervention.