Pfizer announced Monday that its vaccine demonstrated more than 90% effectiveness and no bad reactions and trial results,

an outcome that should enable the company to obtain an emergency authorization in a couple of weeks once it has more data.

The two-dose vaccine, given three weeks apart, is being

called one of the biggest medical breakthroughs in a century. On Monday, with the sixth straight day of

100,000-plus daily coronavirus cases and the rolling average of deaths per week rising toward the

1,000 market yet again,

any break was bound to feel like a big one.

Markets are soaring right now. You see the big board right there, the Dow up more than a thousand points.

Pfizer's stock price jumped nearly 8% in optimism. Its vaccine could unlock economies,

lifted up companies that have been battered by COVID.

Between the vaccine and the unveiling also on Monday of a Biden-led COVID task force,

it seemed like the rare pandemic era day in which the good news could compete with the tragic.

Certainly the vaccine experts out there are all quite excited.

I would say it's fairly universal.

But Pulitzer Prize-winning science writer Lori Garrett wrote this week in foreign policy

that even if this vaccine works is advertised,

there are still plenty of reasons to worry about how much good it can do,

beginning with caveats about the vaccine itself. We have never made a vaccine and certainly

never administered it to human beings before that was made from messenger RNA, which is

the sort of translation that carries the signals from your DNA

blueprint to the ribosome to make proteins. And in this case, the protein it's supposed to be

instructing your body to make is the spike protein, which sticks out from the outside of the virus.

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