Catch up on the latest news, from the DealBook newsletter.

Every day, the DealBook newsletter helps subscribers makes sense of the latest business and policy news. Here are some of the stories in today’s edition:

Pfizer releases the final results of its Covid-19 vaccine trial. The drugmaker said today that its treatment was 95 percent effective and had no serious side effects, two weeks after its initial findings propelled hopes about coronavirus vaccines. Pfizer said it planned to apply for F.D.A. emergency authorization “within days,” and could have enough doses for 25 million people available by the year’s end.

Apple halves its App Store fees for small developers. The company said it would charge a 15 percent commission on app sales for developers who brought in $1 million or less in the past year. Apple has been accused of abusing its control of the App Store by developers like Epic Games — whose chief executive, Tim Sweeney, happens to be speaking at the DealBook Online Summit today (we’ll be sure to ask him about it).

Dolly Parton, Covid-19 vaccine investor. The singer has drawn praise for funding research that produced Moderna’s coronavirus vaccine, which the company said this week was 95 percent effective. The back story: She donated $1 million to Vanderbilt, and that helped pay for early research into the treatment. Now try singing “Vaccine” to the tune of “Jolene.”

Elsewhere in the newsletter, DealBook reporters noted why Judy Shelton’s Federal Reserve nomination suffered another setback; what Mars sees in the maker of Kind bars, which it is buying for $5 billion; and how Facebook’s Mark Zuckerberg and Twitter’s Jack Dorsey endured a marathon senate hearing about the law that shields them from liability for what their users, including President Trump, post to their platforms.