Don’t Assume It’s 'Just A Cold': What To Know About Delta & Breakthrough Infections

There was about one month since the pandemic began that I wasn’t obsessively worried about COVID. From about May through June of this year, I felt like I could sort of calm down. All of the older people in my extended family were fully vaccinated. My husband and I were fully vaccinated, and our teen son was well on his way to being fully vaccinated.

Not only that, but COVID numbers in my community had plummeted to among the lowest levels they’d been at since the pandemic had begun. The same was mostly true all over America. Those online COVID maps were all pretty green and yellow, indicating low levels of COVID infections levels far and wide.

I was beginning to think there was light at the end of this nightmare. Then along came Delta.

How Delta Infections Are Different

The Delta variant, first identified in India, and responsible for huge and deadly surge there over the spring, is the most contagious form of COVID-19 to date, and it’s wreaking havoc all over the world. Now it’s reached our shores, and it’s driving up cases in the U.S.—especially in places with low vaccination rates, but also in places that are highly vaccinated. It really is that contagious.

Now only that, but Delta seems to be causing more breakthrough infections among vaccinated people, and seems to be hitting younger populations more (probably in part because they are less likely to be vaccinated).

As such, some of the symptoms of COVID appear to be changing. Among more vulnerable, unvaccinated people, many of the same serious symptoms remain, including shortness of breath, fever, decreased oxygen levels, multi-organ failure, and death.

But both among fully vaccinated people and younger people who have milder infections, COVID is often looking a whole lot more like the common cold.

Don’t get me wrong—especially among unvaccinated people, those common cold symptoms can evolve to be something more serious, and even milder infections can turn into long-haul COVID situations.

But during this stage of the pandemic—especially as more of us are interacting with others, and other cold-like viruses are circulating—we should always assume that any cold-like virus could be COVID, even if our symptoms are mild.

What To Know About Breakthrough Infections

The COVID vaccines we have are truly amazing, and are helping control the spread of COVID, even with the highly contagious Delta variant spreading. If you look at the current COVID rates, COVID is spreading most in states with low vaccination rates.

However, almost no vaccine is 100% effective against all infections. We always knew that, but now that COVID is spreading quickly again in America, we are seeing more cases of the infections in fully vaccinated people. Not only that, but studies show that the Delta variant is somewhat more likely to cause breakthrough infections in fully vaccinated people.

As Business Insider explains, the vaccines are anywhere from 64%-88% effective against Delta infections, depending on which study you look at. On the other hand, the mRNA vaccines (Pfizer and Moderna) were more like 90-95% against the original strain of COVID. That doesn’t mean that the vaccines are less awesome: they still protect you against severe disease, and the vaccines reduce your chances of hospitalization by over 90%.

COVID Breakthrough Infection Symptoms

So what does a breakthrough infection look like, if you happen to get one?

Well, often you might not even know you are sick, since many breakthrough infections are asymptomatic, and are only caught because of surveillance testing (this was the case when it came to the recent breakthrough infections that were detected at the White House, for example).

Most people who get breakthrough infections are going to feel mild symptoms, such as feeling groggy, feeling like they have a mild cold, or feeling like they have a touch of bronchitis. Others will have more flu-like symptoms, but it will be rare to have severe flu-like symptoms from a breakthrough infection.

Dr. Kirsten Bibbins-Domingo, chair of UCSF’s Department of Epidemiology and Biostatistics, affirms to KQED that most breakthrough infections are mild. Breakthrough infections “have not been the ones that are causing very severe disease that are landing you in the hospital or dying, except in very rare cases,” says Dr. Bibbins-Domingo. “So even when they’re breakthrough infections, people tend to have more mild disease.”

Dr. Bibbins-Domingo says that most of the patients she sees with breakthrough infections are experiencing similar symptoms as we’ve seen with COVID for a while, but milder. “The sore throat, the things that might be cold or flu-like symptoms,” she says.

Dr. Russell Vinik, chief medical operations officer at the University of Utah Health in Salt Lake City, tells NBC News that among the fully vaccinated people who contract COVID, he’s seeing symptoms like stuffy noses, scratchy, sore throats, and mild fatigue and fever.

“If you’ve been vaccinated and you have symptoms, don’t discount them. You could still get Covid,” Vinik said. “Don’t think you’re immune to Covid just because you’re vaccinated,” he added.

Delta Symptoms Often Resemble Common Cold Symptoms

Some doctors have noticed a difference between Delta infections in general, as opposed to the infections caused by earlier strains of the virus. This may be because younger people are more likely to pick up the Delta virus, as most of the older population is vaccinated.

Similar to breakthrough infections, infections in younger people—and Delta in particular—tend to resemble symptoms of the common cold. “Doctors are beginning to notice Covid-19 cases that look more like a very bad cold, especially in areas of the country where the highly contagious delta variant is quickly spreading,” NBC News reports.

“We’ve seen a number of folks with cold-like symptoms,” Dr. Robert Hopkins Jr., an internist at the University of Arkansas for Medical Sciences, told NBC News.

Doctors in the U.K., have also noticed this shift, with many of their COVID cases (especially in younger people) resembling common cold symptoms more often. NBC News reports that researchers there are seeing much more cold-like symptoms, including headaches, runny noses, sore throats, and fevers.

As Tim Spector, a professor of epidemiology at King’s College London, explains to NBC News, “What we’ve been seeing in the last month is very much a change in the symptoms.”

What To Do If You Have Any Cold-Like Symptoms

It’s important to understand that in all cases (whether breakthrough or not), any respiratory symptoms mean that you could pass the virus onto others.

“Covid can present in different ways,” Dr. Vinik, told NBC News. “If you think you have a cold, you’re infectious, and whether that’s Covid or a cold, you should consider getting a test.” You should also obviously isolate yourself from others until you get your test results.

Personally, I’ve started to become more assertive about asking the vaccinated people who I socialize with (which is still a small circle of mostly family members) if they have any symptoms. I’m asking them if they have cold symptoms or even if they feel a little “off.” What could be “just a cold” to them, could actually be COVID, and the last thing I want is to get a breakthrough infection myself. Worse than that, I wouldn’t want to take the chance of my unvaccinated child becoming infected with COVID.

I recommend you do the same, whether you are vaccinated or not. Yes, there are a lot of cold-like viruses going around right now, but some of those are actually COVID-19, and as we all know by now, this virus is not something any of us should mess around with.