COVID-19 hospitalizations at Yale New Haven Health’s five hospitals have dropped 27% over the past 10 days, Marna Borgstrom, the system’s president and chief executive officer, reported Monday.

The number of patients fell from 194 on April 23 to 142 on Monday, a “very good sign” that the disease is declining in Connecticut though it’s still “a little premature ... to say we’re coming out of this,” Borgstrom said during a virtual press briefing.

With COVID-19 vaccination appointments going unfilled, Yale New Haven Health officials said they would continue to accept walk-up patients at mass vaccination sites such as the one in Mohegan Sun’s Earth Expo & Convention Center. If demand for vaccinations continues to fall well short of supply, the sites may begin operating fewer days per week, but there are no plans to close any of them, Dr. Thomas Balcezak, Yale New Haven Health’s chief clinical officer, said.

Because of COVID-19’s geographic spread, Yale New Haven Health wants to maintain the statewide footprint of its vaccination sites, Balcezak said.

Yale New Haven Health’s local affiliates — Lawrence + Memorial Hospital in New London and Westerly Hospital — had COVID-19 patient counts of 12 and one, respectively, on Monday. On April 23, the counts were 14 and two, respectively.

Balcezak said he could offer “no good theory” to account for Westerly Hospital’s consistently low COVID-19 patient counts in recent weeks. He said the counts were disproportionately low, given the population of the hospital’s service area.

Backus Hospital in Norwich, a member of the Hartford HealthCare system, reported it had five COVID-19 patients as of Monday morning.

Balcezak said slack in demand for the Johnson & Johnson COVID-19 vaccine has been pronounced since its use was paused and then restarted following reports of a dozen cases in which people who had received the vaccine developed blood clots. At that point, nearly 7 million doses had been administered.

Yale New Haven Health was prepared to deliver 960 doses of the J&J vaccine at a Greenwich site Monday but only 25 people had signed up by the morning, Balcezak said.

Pop-up vaccination clinics established primarily at churches have been successful in distributing the vaccine to vulnerable, underserved communities.

“We’re trying to lower barriers,” Balcezak said.

Still, he acknowledged it’s becoming more and more evident that the U.S. may never achieve the 70% to 80% vaccination rate associated with “herd immunity,” a view The New York Times attributed to a growing number of experts in an article published Monday.

“We still want to get the message out that it’s safe, effective and in most cases will prevent you from getting the disease,” Balcezk said of the vaccine. “And if you do get the disease, the vaccine will shorten its duration and lessen its severity.”

He likened fighting the pandemic to battling a forest fire. Taking down all the trees would be the equivalent of having everybody vaccinated.

“There’s some benefit in thinning out the fuel,” he said. “We are all standing timber and the virus is the fire. If we can limit what it can spread to ...”

Despite the decrease in the number of COVID-19 patients, Yale New Haven Health hospitals are “incredibly busy,” Borgstrom said. Many patients who delayed care during the pandemic are arriving at hospitals at advanced stages of illness and are having to stay longer. She said there is a "huge backup" in demand for behavioral health services.

b.hallenbeck@theday.com