This randomized controlled trial comprising of almost 3000 asymptomatic adults found the use of either povidone-iodine throat spray or oral hydroxychloroquine to be effective against transmission of SARS‐CoV‐2.

To study the efficacy of prevailing authorized pharmacotherapies useful in decreasing COVID-19 (or SARS-CoV-2) infection.

Healthy individuals under consideration were randomized to receive a 42 day therapy of either:

• Hydroxychloroquine oral (400 mg once, then 200 mg daily),
• Ivermectin oral (12 mg once),
• Povidone-iodine throat spray (3 times daily, 270 µg daily),
• Combination of zinc (80 mg daily) and vitamin C (500 mg daily) oral, or
• Vitamin C (500 mg daily) alone.

SARS-CoV-2 infection confirmed by either: (1) an affirmative serologic test for COVID-19 antibody on day 42, or (2) an affirmative Polymerase chain reaction (PCR) test for COVID-19 at any point between starting and day 42 was regarded as the primary outcome.

Primary analysis included 3,037 asymptomatic adults (mean aged 33 years) who were seronegative to SARS-CoV-2 at starting. Patients who received oral hydroxychloroquine and povidone-iodine throat spray significant absolute risk reductions than vitamin C alone.

No statistically considerable differences were noted with combination of oral zinc and vitamin C and ivermectin.

Disruptions due to adverse effects were greatest among combination of oral zinc and vitamin (6.9%), than vitamin C (4.7%), povidone-iodine (2.0%) and hydroxychloroquine (0.7%) users.

Prevention of  COVID-19 infection was superior with the use of either oral hydroxychloroquine or povidone-iodine throat spray compared to vitamin C in healthy men.