Feeling ill, Michelle Johnson entered the emergency room at Lawrence + Memorial Hospital a couple of weeks ago and, in keeping with hospital protocol these days, submitted to a routine COVID-19 test.

Having had the disease in the fall and been fully vaccinated against it in the spring, she was stunned by the test result.

Positive.

“It was shocking,” she said. “I ended up on a ventilator for two days, then a breathing machine for two days. I was in the intensive care unit for five days.”

Released from the hospital this past Tuesday following an 11-day stay, Johnson, 42, said she’d first gotten COVID-19 in October, catching it about the same time as her 5-year-old son, Timo, and 65-year-old mother, Nancy Anglin, all of whom live together in New London. Anglin's case was severe, but Johnson only suffered flu-like symptoms and her son was asymptomatic.

Johnson had gotten a first dose of the Pfizer vaccine in March and a second dose a month later. She’d been fully vaccinated for more than three months when she tested positive July 23 — a breakthrough case.

“We’ve seen some breakthroughs at L+M, going back to March,” Dr. Kevin Torres, the hospital’s associate chief medical officer, said. “We’re seeing a few more now, but they’re not the majority of cases by any means. Most of the cases we’re seeing are unvaccinated people in their 20s to 50s.”

Fully vaccinated people who are hospitalized with COVID-19 generally are older than 60 and also have a condition like diabetes or asthma or another comorbidity that requires an immunosuppressive treatment, Torres said.

In Connecticut and elsewhere, breakthrough cases represent a small percentage of coronavirus cases overall, though that percentage has increased as the delta variant of the virus has become more dominant. Hartford HealthCare officials this past week reported a slight increase in the percentage of breakthrough cases they’re seeing, a possible consequence, they said, of the strength of the delta variant, which seems to be an especially infective version of the virus.

[naviga:iframe title="Connecticut COVID-19 case rate - vaccinated and unvaccinated* persons" id="datawrapper-chart-FC0Hw" frameborder="0" height="400" scrolling="no" src="https://datawrapper.dwcdn.net/FC0Hw/1/" style="border: currentColor;" width="100%"] [/naviga:iframe]

Dr. Ulysses Wu, Hartford HealthCare’s system director for infectious diseases, said last month’s outbreak of hundreds of coronavirus cases in and around Provincetown, Mass. — incidents in which dozens of Connecticut residents were infected — gave rise to fears that breakthrough cases were more contagious than previously believed.

The U.S. Centers for Disease Control and Prevention studied the Provincetown cluster, identifying 469 coronavirus cases among Massachusetts residents who traveled to the town from July 3 to 17. Of them, 346, or 74%, had been fully vaccinated. Genomic sequencing showed the delta variant was present in 90% of specimens from 133 patients.

Five patents were hospitalized, four of whom were fully vaccinated. No one died.

Wu said he doubts breakthroughs ultimately will transmit at the same rate as the virus in unvaccinated patients but their contagiousness supports the recommendation that masks be worn indoors.

Johnson, the New London woman, said she doesn’t know where she contracted the virus the second time. She said she’s always been careful not to linger in well-populated areas, “runs in and out” of the grocery story while wearing a mask and was required to wear a mask at her workplace.

She and her son noticed there was little or no mask-wearing when they traveled to South Carolina in April, she said.

In defense of vaccines' effectiveness

Doctors were quick to counter the notion that the occurrence of breakthrough cases suggests the coronavirus vaccines — Pfizer, Moderna and Johnson & Johnson — are any less effective than previously thought.

Before the recent surge in cases, the vaccines were credited with knocking down the disease, enabling governments including Connecticut's to roll back restrictions on businesses and entertainment venues.

“Because we’re seeing breakthroughs doesn’t mean the vaccine isn’t working,” said Keith Grant, senior director of infection prevention for Hartford HealthCare. “The reprieve we got over the last two months is from the vaccinations. Our reaction to breakthroughs shouldn’t be, ‘I told you so.’”

Unlike Johnson, most of the fully vaccinated who get the disease don’t require hospitalization. Rarely do they die.

[naviga:iframe title="Connecticut COVID-19 death rate - vaccinated and unvaccinated* persons" id="datawrapper-chart-KCENC" frameborder="0" height="400" scrolling="no" src="https://datawrapper.dwcdn.net/KCENC/2/" style="border: currentColor;" width="100%"] [/naviga:iframe]

The CDC reported that as of July 26, more than 163 million people had been fully vaccinated against the COVID-19 virus in the United States. Forty-nine states and U.S. territories had reported 6,587 cases of breakthrough infections, including 6,239 hospitalizations and 1,263 deaths.

As of this past Tuesday, 1,171 cases of the coronavirus had been confirmed among fully vaccinated people in Connecticut, less than 0.06% of the state’s 2,117,175 fully vaccinated residents. The deaths of 27 of the fully vaccinated were linked to COVID-19.

Data compiled by the state Department of Public Health shows that from February to July, rates of coronavirus cases, COVID-19 hospitalizations and deaths have consistently been higher among unvaccinated people compared to the fully vaccinated. A third wave of the pandemic in Connecticut was attributed to the so-called alpha variant and peaked in early April. All of the rates declined from early April through mid-June, as the third wave waned.

Recent increases in the rates of coronavirus cases and COVID-19 hospitalizations among unvaccinated people suggest a fourth wave of the pandemic is beginning, the DPH has concluded.

“The vaccine is doing its job,” Wu said. “We all thought the purpose of the vaccine was to completely stamp out and prevent disease, but its main goal was to take a deadly disease and turn it into the common cold and it seems to be doing its job in those who are vaccinated."

“From a severity standpoint," he said, "this remains a pandemic of the unvaccinated.”

b.hallenbeck@theday.com