Susan Holtzclaw receives her second dose of Pfizer vaccine from a CVS employee at The Avidor Evanston in February 2021. (RoundTable photo) Credit: Evan Girard

The U.S. Centers for Disease Control and Prevention announced on Tuesday that the COVID-19 omicron subvariant BA.2, dubbed the “stealth” variant by some experts, had officially become the dominant form of the virus in the country.

Since the initial omicron wave in December and January, when Evanston and the entire Chicago region saw the most COVID-19 cases of any point during the pandemic, infections and hospitalizations have plummeted. According to the most recent city update from Monday, March 28, Evanston now has a seven-day average of fewer than eight new cases per day, which is similar to what the city saw during previous periods of low transmission during the early summer and late fall of 2021.

But hospitals and public health leaders have watched with concern in recent weeks as parts of Europe and Asia have seen surges in hospitalizations and deaths fueled by the spread of BA.2, which the World Health Organization and the CDC have said is even more contagious than the highly transmissible original form of omicron. Early research from WHO has demonstrated that BA.2 does not appear to cause more severe disease than BA.1, the initial omicron variant.

Earlier this month, a severe outbreak of BA.2 led to Hong Kong becoming the current global epicenter of the pandemic. The city of 7.4 million, which had effectively shut out the virus through vigorous public health measures up until recently, has experienced a stunning rise in cases and deaths. Just weeks ago, its COVID-19 death rate of 37 deaths per million people was the highest in the world.

Germany, the U.K., the Netherlands and other European countries also have seen recent rapid increases in caseloads. As The Washington Post reported earlier this month, “in the past two years, a widespread outbreak like the one now being seen in Europe has been followed by a similar surge in the United States some weeks later.”

“We are planning for cases to rise again, although honestly I am not sure how much – will it be another surge, or a more manageable increase?” Dr. Jennifer Grant, an infectious disease physician with NorthShore University HealthSystem, told the RoundTable. “The immunity that we have from vaccination and from the recent omicron wave should help cushion us from another surge, but, as we have all learned first hand, COVID can be unpredictable.”

There are reasons to remain hopeful here in the U.S., according to infectious disease experts like Grant. Before this most recent wave, Hong Kong had only seen about 12,000 cases during the entirety of the pandemic, so barely anyone there had natural immunity. Meanwhile, fewer than a quarter of the city’s population older than 80 had received two doses of a COVID-19 vaccine, so the age group most vulnerable to hospitalization and death was also the least protected.

On the other hand, the United States has built up a large amount of immunity naturally through previous virus surges as well as through the particularly effective Pfizer-BioNTech and Moderna vaccines. For example, in December, the CDC estimated that “about 95% of the U.S. population ages 16 and older had antibodies against the virus either through vaccination or infection.”

Of course, that number did not stop omicron from spreading through the population like wildfire this past December and January, but it did help contribute to a milder illness for many people, especially fully vaccinated and boosted individuals.

“It was widely discussed how Omicron/BA.1 was less severe than previous variants like Alpha or Delta, but it seems much of that may have to do with the immunity we had built up from previous infection and vaccination,” Grant said. “Many unvaccinated and high-risk individuals got severely ill from omicron, so I think it’s important to keep that in mind.”

Although Evanston has yet to see a notable increase in cases or positivity rate, Chicago’s latest virus update from March 28 revealed a 27% increase in cases over the previous week. According to Chicago public health guidelines, the rise in infections represents a “substantial” risk of transmission for residents.

That being said, the best strategy for getting and maintaining strong protection from infection, hospitalization and death is to get vaccinated and boosted. Considering the possibility of an imminent increase in cases due to BA.2, the FDA also announced Tuesday that it was authorizing a second booster dose for Americans 50 and older or anyone 12 or older who is considered high-risk.

Given possible waning immunity over time from vaccines or a case of COVID-19, the significance of a BA.2 wave in Evanston highly depends on the uptake of booster shots, especially among the most vulnerable individuals. According to data compiled by The Washington Post, 65.5% of Americans are fully vaccinated, but less than 50% of those people have received a booster.

For its part, though, Evanston has a very high two-dose vaccination rate, including 87.7% of the population older than five and an estimated 100% of residents 65 and older. The city, however, does not track booster rates, and data from the Illinois Department of Public Health shows that 942,563 booster shots have been administered in Cook County as of Tuesday, March 29. That means slightly more than half of fully vaccinated people in the county have gotten a booster.

“I remain most worried about lack of booster uptake among the elderly and the immunocompromised,” Jennifer Nuzzo, a Johns Hopkins University epidemiologist, told The New York Times this week.

The nation’s leading infectious disease expert, Dr. Anthony S. Fauci, said earlier in March that despite a potential uptick in cases, he was not expecting a full-on wave of infections from BA.2. Additionally, a number of other treatments are now available to help alleviate the strain that COVID-19 cases can put on hospitals.

Paxlovid, a course of pills designed by Pfizer that highly vulnerable individuals can take soon after testing positive for the virus, is gradually becoming more widely available in pharmacies and health centers around the U.S.

And for immunocompromised people who have not gotten protection from the available vaccines, a new antibody injection called Evusheld developed by AstraZeneca appears to be highly effective at preventing severe illness and hospitalization. The Biden Administration has purchased enough Evusheld to treat more than 800,000 people, but many of those doses are currently going unused due to confusion over who is eligible and a lack of awareness about the treatment, The New York Times has reported.

As a result, even though vaccines, tests and other treatments are available, federal, state and local governments have to ensure better communication and supply to minimize the impact of future variants and COVID-19 surges.

“Any large COVID surge has the potential to stress our hospital system and others in the area,” Grant said. “That being said, I do think these therapies are a major advantage that we did not have at the beginning, with great potential to help prevent severe illness, hospitalizations and death.”

Duncan Agnew

Duncan Agnew covers Evanston public schools, affordable housing, City Hall and more for the RoundTable. He also writes long-form investigations, features and the morning email newsletter three times a...

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