On 14 July 2020, Moderna scientists published preliminary results of the Phase I dose escalation clinical trial of mRNA-1273, showing dose-dependent induction of neutralizing antibodies against S1/S2 as early as 15 days post-injection. Mild to moderate adverse reactions, such as fever, fatigue, headache, muscle ache, and pain at the injection site were observed in all dose groups, but were common with increased dosage. The vaccine in low doses was deemed safe and effective in order to advance a Phase III clinical trial using two 100-μg doses administered 29 days apart. Moderna and the National Institute of Allergy and Infectious Diseases began a Phase III trial in the United States on 27 July with a plan to enroll and assign 30,000 volunteers to two groups — one group receiving two 100-μg doses of mRNA-1273 vaccine and the other receiving 0. 9% Sodium Chloride. As of 7 August, over 4,500 volunteers had enrolled. According to the Financial Times, Moderna planned to price its vaccine between $50-60 per course.