How safe is our Covid-19 immunity keeping us?

Inconvenient winter realities have dominated life in Western New York this winter – and it’s not just howling winds and tall piles of snow. It’s also powerful sneezes, stifling sniffles and raw-throated coughs.

Four years ago, we would have waved that off as a common cold. Many of us still do, but should we?

“You hear a lot of people have a cold, and at two weeks they’re still feeling tired,” said Dr. Thomas Russo, the chief of infectious disease at the University at Buffalo’s Jacobs School for Medicine and Biomedical Sciences. “Whenever I hear that story, I think, ‘Eh, they more likely had Covid than the common cold.’ ”

That means we’re all likely exposed to – and battling – the virus far more than we may realize. Every time we breathe in some particles of Covid-19, our immune systems are getting a workout. Our defenses are continually training, in a sense, to battle the virus. As a population, we’re getting better at fighting back against Covid-19, but that comes at a risk. Here’s why:

It’s been three years since Covid-19 started spreading widely and quickly around the planet. At this point, nearly all of us have likely been exposed to it, even if we haven’t been knowingly infected. Between that reality and vaccination, that feels like a whole lot of immunity. In the arc of the fight against Covid-19, where do we stand?

Let’s start with what isn’t happening: Herd immunity, or the idea that enough people would develop a durable immune resistance to the virus and essentially snuff it out, is something we haven’t talked much about for a couple of years.

That’s for good reason: Covid-19 isn’t a one-and-done virus like chickenpox. Like influenza or the common cold, you can catch it repeatedly, for a couple of reasons:

• The immunity that comes from infection or vaccination is significant, but absolutely not perfect or permanent.

• Covid-19 immunity wanes over time, and the virus has a pesky penchant for evolving.

Given those factors, and because the virus is still relatively new to our bodies, we’re going to continue living with it.

Living with it. That’s vital.

Three years in, we’ve gotten good at handling Covid-19. Through vaccination and infection, most of our immune systems are better tuned to deal with it, even if we do get infected. Medical professionals, too, know how to handle it better than in 2020, when Covid-19 was surging and, in the literal sense of the term, was a “novel coronavirus.” We have antivirals, like Paxlovid, that work well, and have a clearer sense of what masks can do. (Here’s a cheat sheet: N95s and the equivalent are good to great. Surgical masks are OK. Simple cloth masks and bandanas? That’s like wearing shorts and a T-shirt to walk your dog in the middle of winter: You’ll be covered by appearance only.)

“What we're seeing is people getting sick from it, but they're not winding up in the hospital, not winding up to the ICU and not winding up in the morgue, like we were doing in 2020 and 2021,” said Dr. John Sellick, an infectious diseases specialist with UB, Kaleida Health and Veterans Affairs. “We've seen some moderation in disease.”

What does that moderation look like?

With that moderation, it seems, has come some softening and even consistency in our infection numbers. This winter, Covid-19 is spreading briskly but not harshly. The post-holiday surge from 2021 and 2022 has dampened. Today, as we head into spring, our numbers are similar to one year ago. The average cases per 100,000 people in New York statewide is 7.5 as of March 2, down from 9.7 one year ago. That same figure for Western New York regionally is 9.7 as of March 2. That is identical to one year earlier.

Hospitalization numbers are relatively flat, too. The number of patients with Covid-19 in New York hospitals is hovering around 1,700, the same as a year ago. In Western New York, there are 154 people with Covid-19 who are hospitalized. Last year at this time, the number was 121 people.

About half of the patients statewide were admitted for something other than Covid-19, and happened to have the virus. In a somewhat backward way, that reinforces the idea that we are truly learning to live with Covid-19: We’re still catching it, but the symptoms aren’t often so searingly bad.

“Obviously we’re a whole lot better off than we were a couple of years ago,” Sellick said. “We’ve gotten to the point where we have a good amount of community immunity from vaccination and from prior infection.”

What has the spread this winter meant for people who are immunocompromised?

The starkest risk of Covid-19 – and other serious respiratory viruses – isn’t necessarily to each individual. It’s chiefly to those who have health conditions that put them at risk or to people who are immunocompromised. Someone who is undergoing treatment for blood cancer, or a patients with HIV/AIDs or an organ transplant, may not be able to mount a strong immune response to knock back the virus, even if they have been vaccinated.

Late 2022 and early 2023 brought back the spread of influenza and respiratory syncytial virus (RSV) along with Covid-19.

“It was somewhat jarring to again be faced with a high burden of our standard respiratory viruses,” noted Dr. John Bonnewell, an infectious diseases expert at Roswell Park Comprehensive Cancer Center.

In an email, Bonnewell noted that RSV is particularly “severe and difficult to treat” for immunocompromised patients and added, “Unfortunately, we did experience a number of patients with quite severe illness due to these viruses. Still, the infection burden was well within our capacity to manage, particularly without the large Covid-19 peaks of prior seasons, and fortunately the cases have fallen off as late fall progressed into winter. However, we will need to remain vigilant should a late winter spike of these viruses occur.”

Further complicating matters: Proactive treatments such as certain monoclonal antibodies and the therapeutic treatment Evusheld don’t seem to be effective against the latest Covid-19 variants.

But there is good news: Paxlovid, the medication often prescribed for at-risk patients shortly after a Covid-19 diagnosis, still seems effective at combating the virus, including in immunocompromised patients.

“Thus far,” Bonnewell said, “we have not experienced anything to significantly shake our confidence in Paxlovid.”

OK, so we know Covid-19 is going nowhere, and while there’s still risk, we’re getting good at handling it. Anything else we should be doing?

Continually consider the building blocks of immunity: Having Covid-19 builds your defenses, albeit at a risk. Spending time with someone who has Covid-19, or even breathing in what Russo calls a “whiff” of the virus in a brief interaction, also stokes your immune system, even if you don’t get infected. The one risk-mitigating factor you can fully control is vaccination, which has continually been shown to reduce the likelihood of bad outcomes. But it’s not likely to provide ongoing protection from infection itself.

Keep a frame of reference on the risk: Contracting Covid-19 is potentially complicated for anyone, but especially for people who are older, immunocompromised or have health issues that put them at risk. Even if that’s not you, remember that you can pass it to someone who does fit into one of those categories.

With those factors in mind, live on.

“We are building immunity,” Russo said, adding the “best strategy” is to maximize protection by staying up to date on vaccination and the most recently available boosters, which are the most effective against the current virus variants. He also points that “hybrid immunity,” which includes post-infection and vaccine-induced immunity, “is the best.” If you’re infected, test and talk to your doctor quickly, because a course of Paxlovid may help.

After that, there’s simply hope.

“Hope the amount of virus one is exposed to is small and the consequences of exposure/infection will be minimal,” Russo said. “Of course, unfortunately, there is no guarantee how things will turn out, but max vax will turn the odds in your favor.”