Are We 'Rounding the Corner' in the Pandemic?

Sunday CNN host Fareed Zakaria asked his guest, Dr. Tom Frieden, a former Director of the Centers for Disease Control and Prevention for President Barack Obama, "Is this all happening because more and more people, at least in the U.S., are getting vaccinated, or is there some other explanation?" ["The Good News & Bad News on Covid-19," Feb. 14. See transcript.]

"No, I don't think the vaccine is having much of an impact at all on case rates," responded Frieden. He pointed to two reasons for the drop in cases:

• Behavior: "It's what we're doing right, staying apart, wearing masks, not traveling, not mixing with others indoors."
• The holidays are behind us: "Basically, we're getting over a -- a huge surge around the late-year holidays, starting with Thanksgiving and on to the December holidays."

Fareed followed up by asking when we will see the impacts of increased vaccination—almost 12% of the country has received at least the first dose of a vaccine, according to The Washington Post global tracker on Feb. 15.

"At what point will that start to drive things down, you know, to -- moving closer to herd immunity?"

"In terms of the impact of the vaccination program, what I think will happen is that, within the next few weeks, we'll see substantial decreases in deaths in nursing homes and people over 65," replied Frieden.

"And that is an impact of the vaccines kicking in because they're quite protective.

"But in terms of case rates, it will be many months before we have a big impact from vaccination on the number of cases. That's why it's still important to wear a mask and limit the number of people that you share indoor air with who aren't in your household."

Alternative viewpoint on drop in cases

Dr. Paul Offit, an infectious disease expert at the Children’s Hospital of Philadelphia and "one of the world's recognized leaders in vaccinology," according to Howard Bauchner, editor of the Journal of the American Medical Association who interviewed him on February 11, saw the reason for the drop in cases differently—an increase in immunity from both natural infection and vaccination.

Offit appeared on CNN Newsroom the next day and shared the same analysis with anchors Jim Sciutto and Poppy Harlow (transcript): 

...[I]t's mid-February, this is a winter respiratory virus that should be raging now, but it's not. I mean, we have a decrease in cases, a decrease in deaths, a decrease in hospitalizations. 

And there's one reason for that, I think: immunity. We have -- you list on your site that there's 27 million people who have been infected, but that's just people who have been tested and found to be infected. Most people who had been mildly or asymptomatically infected have never been tested. 

So how do you figure that out? You do antibody surveillance studies to see who's been exposed. And when that's been done -- it was done in November, before the vaccines were out -- that number is off by a factor of four. There's probably 80 to 100 million people in this country who have already been exposed to this virus...

In the JAMA Network podcast, "Coronavirus Vaccine Update With Paul Offit," he warned of two obstacles that could reverse the progress: "Whether coronavirus variants become a problem and whether the anti-vaccine movement or anti-vaccine sentiment becomes a problem."

Offit's optimism notwithstanding, the IHME model paints a grim projection of 615,000 deaths by June 1. As for the "four key factors that will determine how the next few months unfold," they were noted by both Offit and Frieden.

"The first two will likely help the pandemic numbers continue a downward trajectory: increasing vaccinations and declining seasonality -- the pattern of lower transmission that's likely in the US during the spring and summer months," write Maxouris and Andone of CNN in the source article. The other two "can slow or even reverse the declines that have begun," the IHME team said.

The first is the variants, particularly the B.1.1.7 first identified in the U.K. which the CDC has warned may become dominant by the end of March.

The second is what Dr. Frieden warned: "increased behaviors that favor Covid-19 transmission," add Maxouris and Andone.

"Transmission has been contained over the winter through mask wearing, decreased mobility, and avoidance of high-risk settings such as indoor dining," the team said.

That's why experts say now is not the time for the US to let down its guard, even as a growing list of governors loosen Covid-19 restrictions.