4 Fauci takes that provide crucial context for the end of 2020

Last Friday, scientists projected more than 511,000 Americans will have died of Covid-19 by February 2021. It's the furthest projection into the future we've seen yet, and it underscores the fact the pandemic is not ending any time soon.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, has also been thinking about the new year. Here's Fauci's crucial context on the fall surge, why it may be time for a federal mask mandate, the goal of widespread Covid-19 vaccination, and a final note of much-needed optimism.

As a public service, Inverse is aggregating Fauci's comments regularly in the "Fauci Dispatch" series, as the White House has severely limited his visibility to the public. You can read our previous coverage here.

Fauci on the fall surge – Speaking during Yahoo! Finance's All Markets Summit, Fauci put the current surge of Covid-19 cases into context:

"I look at it more as an elongation and exacerbation of the original first wave," he said.

The backdrop – On Tuesday, the U.S. recorded more than 500,000 coronavirus cases in a week, a record for the pandemic began. That puts us higher than the peak of cases this past July when the virus surged in the South and Southwest.

Back then, Fauci made it clear the summer surge wasn't a second wave of the virus. The peak in cases observed now is no different. Cases in the United States were never suppressed to the point of ending the first wave.

There's no actual epidemiological definition of a "wave" but, as Loren Lipworth, an epidemiologist at Vanderbilt, told Inverse in July, scientists tend to look for two signs that a wave has ended: a steep decline in cases and a long interval during which those cases stay down.

If you look at curves for new daily coronavirus cases in Europe, you'll see examples of that structure. Look at Italy or Spain and you'll see a clear peak in cases that then drop off, only to surge once again.

The U.S., however, never saw a steep drop off. Cases never declined enough to signal the end of wave one, nor did the small drop-offs in new cases last very long.

The fall surge we're in right now is simply another peak on that continuous wave — and a sign that steps still need to be taken to get the virus under control.

Fauci on saving lives this winter – Fauci has been reluctant to endorse a federal mask mandate: He's applauded mask mandates from state governors and backed away from the idea of a national one. But when speaking to CNN on Friday, he spoke in favor of universal mask-wearing and mandates intended to get the US closer to that goal.

"Well, if people are not wearing masks, then maybe we should be mandating it," he said.

The backdrop –  Fauci's comments come days after the publication of a paper suggesting that if 95 percent of Americans wore masks and the US implemented social distancing mandates, we could save about 129,574 lives. If 85 percent of Americans wore masks, 95,814 lives could be saved by the end of February.

The model was released Friday by scientists at the Institute for Health Metrics and Evaluation at the University of Washington. It also assumes that 49 percent of Americans are wearing masks – likely a low estimate, the study's lead author Christopher Murray noted on a press call last Friday. (IHME's website now masks projections assuming that 69 percent of people wear masks).

"Well, if people are not wearing masks, then maybe we should be mandating it."

In lieu of a national mandate, mask orders have been left to the states. South Dakota is the only state that doesn't require a mask to be worn in any circumstance — it's also seeing 16 percent of coronavirus tests returned positive, far higher than the five percent threshold states aim to stay below. But there are 14 states that only mandate masks in some areas or circumstances.

The IHME metrics show that we truly need to get as close to that 95 percent threshold as possible to prevent additional loss of life, which may be one reason federal mask mandates may seem more palatable. Though, as Fauci also noted, "there's going to be difficulty enforcing it."

Fauci on vaccines and 2021–  When speaking to the BBC, Fauci gave a rough timeline on when we might expect most Americans to get a coronavirus vaccine:

"When you talk about vaccinating a substantial proportion of the population so that you can have a significant impact on the dynamics of the outbreak, that very likely will not be until the second or third quarter of the year," he said.

The backdrop – Fauci indicated it will be "several months" into 2021 before most people get a coronavirus vaccine. Moncef Slaoui, the chief adviser to Operation Warp Speed (the federal vaccine initiative), has also said that the goal was to have everyone in the country immunized by June 2021.

Ideally, the goal of a widespread vaccination plan would be to create herd immunity. This is the idea that if enough people get vaccinated, then the disease will eventually lose footholds in the community (therefore protecting even those who can't get vaccinated).

Crucially, scientists still don't actually know what the herd immunity threshold for coronavirus actually is and note there is likely no magic number that will guarantee we've gotten there.

The more infectious a disease is, the more people need to be vaccinated for herd immunity to happen. The World Health Organization has suggested that about 60 to 80 percent of people would need to get vaccinated in order to get there with coronavirus, but that may not actually be the case everywhere.

If there are substantial and clustered pockets of unvaccinated people within a community, there are still chances an outbreak can happen. In a model informed by the measles outbreak of 2019, scientists found that even if 95 percent of people were vaccinated against measles, there was an 87 percent chance of an outbreak in a city the size of Buffalo, New York — provided there were significant local clusters of unvaccinated people.

Measles is far more contagious than Covid-19. But as Nina Masters, the first author of that paper, told Inverse, it still tells us that each individual town will probably have to hit a different threshold of vaccination before herd immunity is achieved.

"I think the lessons from measles, and what we show in this paper, is that herd immunity shouldn’t be seen as a magic number to hit on a state or national scale," she said.

Fauci points to a silver lining –  Speaking at a virtual event at the Yale School of Public Health, Fauci provided a much-needed silver lining as cases climb:

"It’s going to get better and better gradually. It’s not going to be horrible until the end of 2021… people are going to start to see the sun coming up," he said.

The backdrop –  With a winter surge unavoidable, it's hard to imagine how this year could possibly be much better than the last. But there are small rays of light.

We know that masks work and can save thousands of lives. There's emerging evidence that doctors are getting better at treating the virus. And there are 11 vaccines in the third and final phase of human testing, with a good chance of delivering at least one useful candidate by the end of the year, Fauci noted in the BBC interview.

It's not a normal life, but it's better than last winter when the virus struck an unaware world.