Coronavirus vaccine: What we know about 3 of the most promising vaccines in development so far

At least two companies have said their coronavirus vaccines have proved to be at least 90% effective during clinical trials so far.

Those developments come as virus cases topped 11 million in the U.S. over the weekend — 1 million of them recorded in just the past week. In Florida, the state recorded its largest spike in cases since July on Sunday, recording 10,105 new cases.

READ: Coronavirus: What is a clinical trial?


The results are “truly striking,” said Dr. Anthony Fauci, the U.S. government’s top infectious diseases expert. Earlier this year, Fauci said he would be happy with a COVID-19 vaccine that was 60% effective.

Here’s what we know about the three most promising vaccines so far:

READ: Orange County prepping for storage, disbursement of future COVID-19 vaccine


Biotech company Moderna said Monday that an early analysis has revealed that its COVID-19 vaccine candidate was 94.5% effective in its clinical trial.

In a news release, Moderna said the independent Data Safety Monitoring Board for the Phase 3 study of its vaccine candidate, mRNA-1273, said the trial “has met the statistical criteria pre-specified in the study protocol for efficacy, with a vaccine efficacy of 94.5%.”

READ: Coronavirus: Moderna says early analysis shows COVID-19 vaccine 94.5% effective

Pfizer Inc.

Pharmaceutical company Pfizer announced last week that its COVID-19 vaccination has been shown to be 90% effective against the novel coronavirus, and that it will petition the U.S. Food and Drug Administration for an Emergency Use Authorization to begin using the vaccine.

Pfizer plans to ask the FDA for emergency authorization of the two-dose vaccine by the end of this month. First, it must follow half of the patients in their study for any safety issues for at least two months following their second dose. According to Pfizer, it expects to cross that threshold by the third week of November.

According to the company, it will have enough doses manufactured to immunize 15 million to 20 million people by the end of the year.

READ: Coronavirus vaccine: How does the Pfizer vaccine work and when will it be available to everyone?


AstraZeneca hopes to show its COVID-19 vaccine is effective by the end of this year, and is ramping up manufacturing so it can supply hundreds of millions of doses starting in January, Chief Executive Pascal Soriot said earlier this month.

The Anglo-Swedish drugmaker is working with the University of Oxford to develop one of the most closely watched COVID-19 vaccines, which is in late stage trials in the U.S., Great Britain and other countries to determine its safety and effectiveness. Once those results are reported, regulators will have to approve the vaccine for widespread use.

READ: AstraZeneca to deliver vaccine trial data by year’s end

The Associated Press contributed to this report.

Sarah Wilson

Sarah Wilson,

Sarah Wilson joined WFTV Channel 9 in 2018 as a digital producer after working as an award-winning newspaper reporter for nearly a decade in various communities across Central Florida.