We recently dug in on the seven factors that are most critical in understanding the current delta surge. But if you're trying to keep up with the firehose of news on the delta variant, it's not enough to know what to pay attention to—you also have to know what you can safely tune out.
Here, then, are four factors that are grabbing lots of headlines but that, in and of themselves, reveal little about the epidemic's future.
1. Raw Covid-19 case counts
Prior to 2020, nobody had been infected with Covid-19, so nobody had any immunity to the virus's worst effects. In those early days, it was critical to track raw case numbers.
Today, though, raw case counts tell us much less. In particular, if many cases are occurring in vaccinated individuals and are only mildly symptomatic or not very transmissible, a high case count risks overstating the true size of the public health problem. Alternatively, a low case count could mask asymptomatic cases that are never officially diagnosed but could still drive the spread the virus to the more vulnerable.
So when I see a raw case count, I ask myself: How many of those cases lead to serious illness and hospitalizations? What are the demographics of the severely ill and dying? If individuals who are now ill were vaccinated, did their breakthrough infections lead to severe illness?
In particular, severe illnesses—and corresponding hospitalization rates—are likely more important to track, since they relate directly to the health system's capacity to care for patients effectively.
2. The percentage of patients with Covid-19 who had been vaccinated
As more people get vaccinated, it's natural that a greater proportion of Covid-19 cases will occur among vaccinated people. This does not mean that vaccines don't work. (In the unlikely event we ever get 100% of Americans vaccinated, then 100% of cases will occur in vaccinated people. There just won't be very many cases in the first place.)
What you should focus on instead is breakthrough illness: Of breakthrough cases, what proportion lead to severe illness, hospitalization, or death?
So far, the amount of breakthrough illness and death is low. For instance, in the widely reported Provincetown outbreak, 74% of the cases, or 346 total, occurred among vaccinated individuals. That's a scary-sounding number, but only four of those individuals, or about 1%, were hospitalized. None of them died.
To be clear, some people still suffered a serious illness and may have spread the virus to others. Breakthrough infections are no joke. Still, these figures are a reassuring sign that existing vaccines are protecting against the worst outcomes of Covid-19.
3. The fact that a new variant has emerged—until you learn more about it
Mutations develop as a natural by-product of viral replication. This happens with every virus, including the seasonal flu, and it's the fundamental driver of new Covid-19 variants.
You should expect to new variants to emerge beyond delta, and the more significant ones will have new names inspired by the Greek alphabet. But the fact that a variant is "new" doesn't mean that it's "worse," or even different from prior variants in any clinically significant way.
So until more is known about a new variant (or a subvariant, such as the so-called "delta plus"), you shouldn't automatically add it to your pandemic worry list.
When should you start worrying? It's worth keeping an eye on the World Health Organization's designations of coronavirus variants, which includes the designations of "variants of concern" (the most worrisome, including delta), "variants of interest" (those that could become more serious), and "alerts for further monitoring" (for variants about which little data exists).
Some additional questions you might ask yourself as evidence emerges: How transmissible is the new variant? Does it commonly lead to severe infection, hospitalization, and/or death? And perhaps most importantly, do current vaccines protect against serious illness caused by this variant?
4. The unexpectedly frightening (or encouraging) findings of any one study
If it hasn't happened yet today, it probably will soon: Your phone will buzz with an alert about a new study offering a terrifying statistic about the delta variant. Or maybe the next alert will be more encouraging, suggesting that some inexpensive drug or vitamin can avert infection.
It can be exhausting and, at times, whiplash-inducing to keep up with all these latest, sometimes contradictory headlines. But here's the good news: You don't have to.
At this point in the Covid-19 pandemic, it's rare that any one study should dramatically change our understanding of the coronavirus or its course. The core truths are well-established.
We know, for instance, that the vaccines authorized for use in the U.S. have all shown to be effective in preventing hospitalizations and death, including against the delta variant. Yes, some emerging evidence suggests vaccines are less effective in preventing mild illness from delta—but most studies so far are geographically limited, small in sample size, and prone to confounding errors. They may well be picking up a real effect, but given their inherent limitations, they shouldn't cause you to overhaul your beliefs on vaccine efficacy overnight.
So when should you shift your beliefs? Data from large, randomized controlled trials are, of course, the gold standard. Peer-reviewed studies are probably more reliable than preprint studies. And it's worth monitoring the recommendations of public health experts, such as Anthony Fauci and CDC, who are doing their best to sort through mountains of incomplete and contradictory data.
The biggest distraction? Anything that takes your focus away from vaccinations.
Our No. 1 focus should be on preventing the severe illness, long-term effects, and mortality that we know can come with a Covid-19 diagnosis. Vaccines are far and away the best way to achieve that goal—yet nearly 30% of U.S. adults still haven't been vaccinated.
Vaccines aren't perfect, so it makes sense for us also to take additional actions to prevent disease, such as mask-wearing, social distancing, and making reasonable tradeoffs related to indoor activities. But fundamentally, this pandemic won't end until vastly more people are vaccinated, both in America and worldwide.
If there's anything you can do today to help more people get vaccinated—whether through your job in the health care industry or simply by speaking, candidly and empathetically, to your friends and family—here's my suggestion: Keep 100% of your focus on that vital work.
Advisory Board's Andrew Mohama and Thomas Seay contributed to this piece. Pamela Divack contributed additional research.