https://clinicaltrials.gov/ct2/show/NCT04368728 (Pfizer, >40000 participants)
https://clinicaltrials.gov/ct2/show/NCT04470427 (Moderna, 30000 participants)
https://clinicaltrials.gov/ct2/show/NCT04368728 (Pfizer, >40000 participants)
https://clinicaltrials.gov/ct2/show/NCT04470427 (Moderna, 30000 participants)