US FDA says two different MRNA vaccines have now shown effectiveness of about 95%

US FDA statement on following the authorized dosing schedules for Covid-19 vaccines

• says "two different MRNA vaccines have now shown remarkable effectiveness of about 95% in preventing Covid-19 infection in adults"
• "suggesting changes to the FDA-authorized dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence"
• available data continue to support the use of two specified doses of each authorized vaccine at specified intervals
• for Pfizer-Biontech vaccine, interval is 21 days between 1st & 2nd dose; for Moderna covid-19 vaccine, interval is 28 days between 1st & 2nd dose
• what we have seen is that the data in the firms' submissions regarding the first dose is commonly being misinterpreted
• until vaccine makers have data supporting change we continue to strongly recommend health care providers follow FDA-authorized dosing schedule

The FDA is responding to the suggestions in the US (and UK) to delay the 2nd dose of vaccine so as to allow wider distribution of first doses.