COVID-19 - Dr. Jim Halverson

COVID-19 - Dr. Jim Halverson

Ask Dr. Halverson: There is a good chance the worst of the pandemic is behind us

web 4 17 Halverson photo
By Dr. Jim Halverson
According to recent polls, two-thirds of Americans are either somewhat or very worried about the newer, potentially more contagious COVID-19 variants that are now present in the United States.
I think there is reason for us to worry less, and become more hopeful that the worst of the pandemic is behind us.
To be clear, worrying less about variants doesn’t mean stopping precautions; nothing will suppress cases and shorten the pandemic in the United States like wearing a mask, avoiding indoor gatherings, staying 6 feet apart and getting vaccinated.
The precautions taken by both individuals and public officials in response to America’s deadly holiday surge have helped turn the tide of transmission. Warming weather means less indoor crowding. More than 15% of the U.S population — a large number of them susceptible older individuals living in congregant facilities or working in medical settings where outbreaks tend to begin — have received at least one dose of an extremely effective vaccine that not only confers near-complete protection from disease and death within weeks, but likely reduces transmission. The pace of vaccination is also continuing to pick up, with 140 million more doses set for delivery in March, an additional 200 million expected by the end of May and enough to vaccinate all eligible Americans by the end of July or sooner.
In addition, the only upside of America’s horrifically high case count, which nearly tripled from 9 million to 26 million between November and February (and is currently more than 28 million as of Feb. 26), is that tens of millions have already acquired some degree of immunity through infection. 
As a result, U.S. COVID-19 cases and hospitalizations have been dropping substantially over the past six weeks. Though still much too high (fewer than 10,000 cases per day and dropping is hoped for), the  current average daily case count (around 70,000) is the lowest since Oct. 24. Deaths, a lagging indicator, are down more than 20% over the past three weeks. We are heading in the right direction.
The current and future variants could still increase in prevalence this spring and cause a “fourth wave” of cases if we let down our guard and go too far in relaxing restrictions. But the current downward trajectory of cases may decrease the potential impact of those variants.
For a variant to qualify as dominant, it simply needs to account for a majority of cases. That sounds scary in a headline, especially when we’re discussing a variant such as B.1.1.7. (the U.K. variant) that is 50% more transmissible than earlier versions of the virus and potentially more deadly. However, a dominant variant is a lot scarier when we have a large number of cases than when we have a much smaller number of cases.

 

Pandemic forecaster
Consider this example from Youyang Gu, an independent and highly respected data scientist trained at the Massachusetts Institute of Technology, who has proved to be one of the pandemic’s most accurate forecasters. First, Gu points out an important fact: “The claim that the variant is doubling every 10 days is false.” He states, “It’s the proportion of the variant that is doubling every 10 days.”
Gu provides the example of having 100 cases on Day Zero, and the variant is responsible for 10 of them. It’s this percentage — as opposed to the actual number of cases — that’s doubling every 10 days. Despite all of the concerning news alerts, such doubling doesn’t necessarily doom us to a big new wave of infections. Instead, it would look something like this:
— Day 0: 100 total cases / 10 variant cases = 10% variant
— Day 10: 75 total cases / 15 variant cases = 20%  variant
Day 20: 50 total cases / 20 variant cases = 40%  variant
In Gu’s hypothetical scenario, the proportion of the variant is doubling every 10 days and it’s well on its way to becoming dominant. But cases still fall by 50% overall.
Of course, the actual U.S. pandemic won’t follow this precise arc. But it is certainly possible for cases to drop even as an opportunistic variant such as B.1.1.7. inexorably accounts for a larger and larger share of them. For proof, look at the significant drop in cases in the United Kingdom, Denmark, Switzerland, Portugal and Israel — all countries where B.1.1.7. predominates.

Plateau in cases predicted
The United States isn’t as good at maintaining mitigation measures as its overseas counterparts. But it’s better than most at vaccination, and it’s a lot farther along at acquiring protection through prior infection. The leading forecasting models currently predict a modest “plateau” in infections during March or April followed by continued decline. Even if cases do level off or temporarily rise, deaths and hospitalizations should keep falling as increasing numbers of older and higher-risk Americans get vaccinated.
Reaching herd immunity, the theoretical threshold when 75% to 90% of the population is protected and the virus runs out of people to infect, might prove unattainable in the United States. The vaccines likely won’t be approved for children (roughly 20% of Americans) before next year, and another 24% of Americans say they won’t get vaccinated at all.
However, the end of the U.S. COVID-19 crisis — the current state of emergency that has required us to stay home and stay masked to keep hospitals from overflowing and vulnerable people from dying — should arrive later this year. By this summer, vaccines will be available to all Americans 16 and older. Around the same time, Gu estimates, the number of “susceptible” Americans — which he defines as anyone older than 45 who lacks immunity — will have fallen from about a third of our population at the start of 2021 to 10% or fewer. 
At that point, COVID-19 would look less like a pandemic and more like a public health problem on par with familiar flu or cold strains, with less threat of severe illness and very little burden on hospitals. We should then be able to remove our masks and hug our friends and family.
Here is the clear message for all of us: Our social lives will resume, but only when our whole community is ready. The turning point does not arrive for individuals once they have been vaccinated. It will come for all of us, at the same time, when our population reaches substantial immunity. It will primarily be a function of how quickly our entire community gets access to the vaccines, how much immunity already exists in our population, and how much attention we continue to give to basic preventative measures. Much of this is in OUR hands now. 
Stay hopeful, stay diligent, stay properly informed, stay safe and stay well.

— Dr. Jim Halverson of Ojai is a longtime Ojai physician who writes a weekly column on COVID-19 for the Ojai Valley News.