How to calculate risk in the era of long covid

Today, while the number of cases remain substantial — the recent daily national average of 106,000 is surely a significant undercount — the level of daily deaths (327) is near the lowest point it’s been in the pandemic. At this point, at least in the United States, most people — excepting the immunocompromised, the very elderly and a few other groups ­ have the capacity to keep themselves relatively safe from a severe case of covid with vaccines, boosters, antivirals, masks, ventilation and more. The phrase “no worse than the flu” has morphed from a covid-minimizing canard into an epidemiologically accurate statement — at least when it comes to hospitalizations and deaths.

The easing of the threat of acute covid, however, has brought the dangers of long covid into focus. With high case rates in my city, San Francisco, I don’t do indoor dining and I wear a KN95 mask in crowded indoor spaces such as supermarkets, theaters and airplanes. Unlike in the early days of the pandemic, it’s not because I fear dying of covid; I no longer do, even though I’m in my mid-60s. It’s because of long covid.

I’m a 64-year-old vaxxed doctor. Here’s how I calculate my covid risk at parties.

There have been many studies assessing the risks of long covid (generally defined as any symptom persisting more than one or two months after the acute infection). Most find that the prevalence of long covid is approximately 10 to 20 percent. The prevalence seems to be a bit lower in men than women, lower if the initial infection was mild, lower after an omicron infection as compared with prior versions of the coronavirus and lower after vaccination. Even with all these mitigating factors, the best-protected person still likely has at least a 1-in-20 chance of lingering symptoms if they get covid today. And while some cases of long covid involve a single symptom that doesn’t markedly diminish quality of life (such as a cough or mild taste disturbance), others involve disabling symptoms such as profound fatigue, severe brain fog or intense shortness of breath.

I have seen the toll of long covid firsthand. My wife contracted covid while teaching at a science writers’ conference. A healthy 64-year-old who has been vaccinated and boosted, she had an uneventful initial bout with the virus. Yet seven weeks later she continues to suffer from extreme exhaustion and feels as if her brain is working in slow motion. “I can concentrate on something for an hour or so, and then I need to nap,” she says. While she’s slowly improving, she is still nowhere near her baseline levels of function or cognition.

Watching her struggle highlights the complexity of our current moment, as we all attempt to recalibrate our covid fear level appropriately. Given the levels of protection against severe disease provided by both previous infection and by the vaccines — especially the latter — I can understand why many people would choose to be done with caution, and done with covid. But long covid throws a wrench into the calculation.

In addition to symptoms that last for several months or more, there’s also a risk of other long-term complications that are set in motion by the original case of covid-19. For reasons that aren’t completely understood, people who have had covid have a significant increase in heart attacks, stroke, diabetes and blood clots, measured at least one year from the time of their infection. There is evidence, too, of brain shrinkage, although the implications of this are not yet clear. These findings mean that, on top of the risk of chronic symptoms, a case of covid may increase the long-term odds of several diseases that are among our leading causes of death and disability.

Given such risks, what’s a person to do? First of all, if you haven’t gotten at least three vaccine shots, you should make sure you do. Up-to-date vaccination — in addition to its other benefits — lowers the odds of long covid by 15 to 50 percent, depending on the study. (While there are theoretical reasons to believe that the anti-viral drug Paxlovid may also decrease the chance of long covid, there is currently no empirical proof that it does.)

Beyond that, I continue to favor taking more precautions than you would if you were looking only at the figures for deaths and hospitalizations. For my part, I will ditch the mask at the supermarket and resume indoor dining when I am confident that case rates have fallen considerably, to below 10-20 cases per 100,000 per day. (The current official U.S. case rate of 32 per 100,000 per day probably translates into an actual count of approximately 120-150 when one takes into account all the unreported cases diagnosed through home testing.) Unfortunately, there’s no guarantee of when that will happen — or even if it will happen, considering that more infectious and immune-evasive variants continue to crop up. I’ll continue to be careful for as long as it takes.

Some people will see my current carefulness as excessive — particularly since vigilance is no guarantee of remaining covid-free, and the risk of short-term morbidity and mortality is now relatively low. But for me and many others, the price of remaining careful — even if variants can sometimes, if rarely, evade even a good mask — seems lower than the risks of long covid. While the drop in severe acute covid cases is cause for celebration, covid’s long-term threat deserves our respect.