The Food and Drug Administration's standard is that a vaccine be more than 50 percent effective at protecting people compared with a placebo shot, so this 90% mark far exceeds that.
"It's big news because it means the vaccine they've developed is effective in blocking covid from infecting individuals and that's how the trial works, you get vaccinated, and see if it provides protection for people in their daily life," said Dr. William Morice, Mayo Clinic Laboratories President.
The early data is from a small batch, just over 90 participants, of a large scale study that involves more than 40-thousand volunteers.
There are still a lot of questions to be answered including how effective the vaccine is in the elderly verse younger people. That's yet to be determined. And the next step is to determine safety.
"The Pharmaceutical companies agreed they would wait two month interval after the median number of participants are vaccinated, and they haven't hit that time point yet, for this particular vaccine, I think it will be in 3rd week of November, that's when they'll be able to look and say are we seeing any safety concerns?" said Dr. Morice.
In a few weeks we should be getting more data from Pfizer on safety after it has collected the recommended two months of safety data. It's a two dose vaccine-- but data does not indicate how long it protects against Covid.. And the next big question is distribution. Pfizer's CEO said they project to produce globally up to 50 million vaccine doses this year and up to 1.3 billion doses next year. This is based on FDA approval on an emergency basis.
The Trump administration says they're ready to start shipping it to pharmacies as soon as it's approved.
Moderna is developing a similar MRNA type vaccine-- and doctors say there could be new vaccine data coming soon.