New York, Nov 16 (IANS): For the second time in the span of 10 days after the US elections, there's a Covid-19 gamechanger on the horizon with US pharma giant Moderna announcing that its vaccine has shown more than 94 per cent effectiveness in preliminary data from the company's ongoing study.

Pfizer Inc had announced 90 per cent efficacy exactly a week ago. Taken together, these two vaccines are firmly on course to seek emergency use authorisation from the US Food and Drug Administration if results hold out in final study results due soon.

Anthony Fauci from Trump's coronavirus task force is optimistic that these early vaccines will change the course of "everything we do" over the next few months.

Pfizer's final results are due in the third week of November - around the time of the Thanksgiving holiday.

Covid cases in the US crossed 11 million by November 15, with the latest 1 million coming in a week. The country's death toll is the world's highest - more than 246,000 at last count.

Roughly 20 million people could be vaccinated against the coronavirus in December, the chief of the Donald Trump administration's vaccine coordination programme has indicated. Anywhere from 25 to 30 million people could be vaccinated each month after that.

The US is working with a portfolio of six vaccines, using three different platform technologies and two candidates from each platform: Messenger RNA, live viral vectors and recombinant protein.

Pfizer and Moderna's vaccines use the messenger RNA platform, Johnson and Johnson and AstraZeneca in partnership with Oxford University are on the live vector path while Novavax and Sanofi/GlaxoSmithKline are building out their vaccine candidates on the recombinant protein platform.