Coronavirus Covid19 between people in glassy protection. Social distancing in coronavirus pandemic. 3D illustration

In May, New York City raised its Covid-19 alert level to high amid increasing pressure on the health care system. Guidance during a high alert level encourages New Yorkers to wear a face mask in all public indoor settings and crowded outdoor settings. Mayor Eric Adams had not reinstated a mask requirement as of late May.

Alert levels take into account cases, hospital admissions and the percentage of inpatient beds occupied by Covid-19 patients. A high alert level is triggered when new hospital admissions over seven days surpass 10 per 100,000 and the percentage of staffed inpatient beds occupied by Covid patients is greater than 10%, according to guidance from the US Centers for Disease Control and Prevention.

New admissions were at 9.8 per 100,000 and increasing as of May 13, while 4.14% of inpatients beds were occupied by Covid patients. City Health Commissioner Ashwin Vasan said he doesn’t expect the current wave to last, as long as residents follow the city’s guidance.

How Often Can You Be Infected With the Coronavirus?

Since Covid shows no signs of disappearing, variants that are adept at dodging the body’s defenses have some scientists concerned waves of infections could occur two or three times a year. The central problem is that the coronavirus has become more adept at reinfecting people. Already, those infected with the first Omicron variant are reporting second infections with the newer versions of the variant – BA.2 or BA2.12.1 in the United States, or BA.4 and BA.5 in South Africa.

Those people may go on to have third or fourth infections, even within this year, researchers said in interviews. Some small fraction may have symptoms that persist for months or years – a condition known as long Covid.

It’s difficult to quantify how frequently people are reinfected, in part because many infections are now going unreported.

This is not how it was supposed to be. Earlier in the pandemic, experts thought that immunity from vaccination or previous infection would forestall most reinfections. The Omicron variant dashed those hopes. Unlike previous variants, Omicron and its many descendants seem to have evolved to partially dodge immunity. That leaves everyone – even those who have been vaccinated multiple times – vulnerable to multiple infections.

The new variants have not altered the fundamental usefulness of Covid vaccines. Most people who have received three or even just two doses will not become sick enough to need medical care if they test positive for the coronavirus. And a booster dose, like a previous infection, does seem to decrease the chance of reinfection – but not by much.

At the pandemic’s outset, many experts based their expectations of the coronavirus on influenza, the viral foe most familiar to them. They predicted that, as with the flu, there might be one big outbreak each year, most likely in the fall. Instead, the coronavirus is behaving more like four of its closely related cousins, which circulate and cause colds year-round.

To keep up with the evolving virus, experts say Covid vaccines should be updated more quickly, even more quickly than flu vaccines each year. Even an imperfect match to a new form of the coronavirus will still broaden immunity and offer some protection, they said.

Sources: Crain’s New York Business, The New York Times