Inclusion Criteria:  Male or female participants must be at least 18 years of age, inclusive, at the time of signing the informed consent form. Confirmed SARS-CoV-2 polymerase chain reaction (PCR) positive patient within 5 days of enrollment, as shown by medical history and reported PCR test result. Reports having one or more symptoms consistent with SARS-CoV-2, as defined in Master Protocol Appendix 3 Table 4. COVID-19 diagnosis must be WHO grade ≤3. Contraceptive use by men or women should be consistent with Appendix 4 of the Master protocol (LDOS-21-001). Reliable access to the Internet via a browser installed on personal device or computer. Capable of understanding and providing signed informed consent.  Exclusion Criteria:  Pregnancy or breastfeeding Ongoing antiviral or antiretroviral treatment Known history of HIV  Ongoing anti-inflammatory treatment that cannot be temporarily discontinued during the study. This includes nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroids - including Dexamethasone (dexamethasone administration restricted to recommended standard of care use per NIH COVID-19 Guidelines)  drugs dependent on gastric pH for absorption, e.g., dasatinib, delavirdine, mesylate, cefditoren, and fosamprenavir; tizanidine (CYP1A2) substrate; drugs that interfere with hemostasis (e.g., warfarin, aspirin, selective serotonin reuptake inhibitors [SSRIs]/serotonin norepinephrine reuptake inhibitors (SNRIs]); angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB), or beta-blockers; diuretics; digoxin Ongoing treatment that cannot be temporarily discontinued during the study, with: antimalarials, antiarrhythmics, tricyclic antidepressants, natalizumab, quinolones, macrolides, agalsidase alfa and beta Ongoing famotidine or celecoxib or other COVID-19 clinical investigational treatment(s) within the past 30 days, or current participation in another investigational clinical trial History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs History of immunosuppression Rejection of participation by Principal Investigator or Sponsor  Any contraindication for famotidine or celecoxib treatment:  Famotidine or celecoxib hypersensitivity Retinopathy, visual field or visual acuity disturbances History of cardiovascular disease, such as congestive heart failure, QT prolongation, myocardial infarction, bradycardia (<50 bpm), ventricular tachycardia, other arrhythmias Myasthenia gravis Psoriasis or porphyria History of renal failure/dialysis or a glomerular clearance <60 mL/min History of severe hypoglycemia Moderate or severe hepatic impairment, e.g., Child-Pugh Class B or C Known or suspected to be poor CYP2C9 metabolizers based on genotype or previous history or experience with other CYP2C9 substrates, such as warfarin and phenytoin