ALERT: Asymptomatic spread of COVID-19 is a bigger threat than you might think

It’s no secret that universal mask wearing is vitally important while we’re still in the grips of COVID-19. But today, I want to share a new finding that underscores that message in bright red ink.  

As I mentioned on Tuesdaythe main purpose of wearing a mask isn’t to protect yourself from infection. (Though it certainly does confer some protection to you.) The real goal is to keep your fellow Americans safe from you. 

Because here’s the truth: More than half of all COVID-19 transmissions come from unsuspecting patients with no symptoms at all. And we have the data to prove it.  

Spreading without symptoms 

This recent study comes courtesy of the U.S. Centers for Disease Control and Prevention (CDC), and appeared recently in JAMA Network Open 

It drew from data from a number of COVID-19 studies from the past year. And it found that while 30 percent of infected patients will never develop any symptoms to speak of, these same patients are still 75 percent as infectious as patients with full-blown, symptomatic cases. 

The scientists modeled transmission scenarios with asymptomatic and pre-symptomatic patients. And they predicted that a whopping 59 percent of transmissions would come from asymptomatic individuals—with 35 percent originating from patients who just haven’t developed symptoms yet, and 24 percent from patients who will never develop symptoms at all.      

I don’t need to point out that this is a significant number of cases. The majority of them, evenSo the advice to stay home if you’re showing symptoms of COVID-19? 

Well, that alone won’t cut it. Especially not if we have any hope of slowing down the breakneck speed of community spread in the weeks and months ahead.  

Stay vigilant—or stay home 

Even with new vaccines rolling out as I write this, we are nowhere near out of the woods yet. And, as I also mentioned earlier in the week, the situation is only going to get more dire in the days and weeks (and months) to come 

I should also point out that even this study’s estimates are based on Chinese studies from the pandemic’s earliest days. But the virus has evolved since then—and the more easily transmitted strain we’re seeing here in the U.S. now may have an even longer pre-symptomatic stage.  

In other words, these latest figures—staggering as they are—might actually be underestimating the role of asymptomatic spread in our country’s fight against COVID-19. 

So… I’ve said it before and I’ll say it again: Now is not the time to let your guard down 

You may feel fine—but that doesn’t mean you’re not shedding this lethal virus everywhere you go. Which is why it’s critical that all of us do our part.  

If you must leave the house, mask up, keep your distance, and wash your hands with soap and water, thoroughly and often. For additional immune-boosting tips, check out my Complete Guide to Year-Round Immunity 


“Over Half of COVID Transmission May Occur via Asymptomatic People.” Medscape Medical News, 01/07/21. (