Conn. breakthrough cases rising

Experts: Few need hospitalization; most COVID cases don’t need critical care

As new coronavirus cases have increased in Connecticut, so have breakthrough infections, though a decreasing percentage of them are resulting in hospitalizations, experts say.

Data provided by the state Department of Public Health shows an increase in breakthrough cases over the past four weeks, a total of 4,143 new breakthrough cases in the week ending Wednesday. That’s an increase from Dec. 2, when there were a total of 2,553 new breakthrough cases.

With the increase in the past week, state data shows that 1.2 percent of all of Connecticut’s fully vaccinated residents have contracted

COVID.

However, the risk remains much greater for unvaccinated people, who are five times more likely to get infected, 12 times more likely to be hospitalized and 16 times more likely to die, according to state officials.

There were 1,550 COVID cases among vaccinated patients in Connecticut identified the week ending Nov. 24, 138 fewer than there were the week prior.

Of the 4,143 breakthrough cases identified this week, most are among patients between 35 and 64 years old. There were 802 breakthrough cases in patients aged 35 to 44, and 842 cases in patients aged 55 to 64.

There were 33 break

through infections among children between the ages of 12 and 15, and 321 cases in patients 75 and older.

A week earlier, no single age group saw more than 500 breakthrough infections.

All told, there have been 29,317 breakthrough infections in Connecticut to date.

By contrast, there was a seven-day average of 1,550 new cases per day, including vaccinated and unvaccinated patients, as of Dec. 7.

On Thursday, the state announced a daily positivity rate of 6.48 percent with 2,679 new cases detected in the previous 24 hours, and a total of 576 patients hospitalized with the virus. There were 37 new deaths reported in the past week for a total of 8,946.

Though older patients are not seeing as high a percentage of breakthrough cases, they continue to see a higher rate of mortality from COVID-19. Of the 213 COVID-relaed deaths in vaccinated patients, 160 of them — more than 75 percent — have been people 75 and older.

The rise in breakthrough cases comes amid broad efforts to encourage Connecticut’s fully vaccinated to get a booster shot. Officials and experts have expressed concerns over waning immunity from the initial course of vaccine now that many residents have been fully vaccinated for six or more months.

Boosters had skewed more toward older residents, who were the first eligible. Younger residents, including those in age groups that have seen a sharp rise in breakthrough infections, have been vaccinated for months, but have only been broadly eligible to receive a booster for several weeks.

Keith Grant, senior system director for infection prevention at Hartford HealthCare, said about 26 percent of the 206 COVID patients being treated at his health system are fully vaccinated.

A tiny percentage of those are in need of critical care. Of those vaccinated patients being treated for COVID at Hartford HealthCare facilities, about 1 percent are in need of mechanical ventilation.

“The majority of individuals who are in critical care are individuals who are not vaccinated,” Grant said.

In addition, many breakthrough infections are incidental — patients who went to the hospital for another ailment and were found to have COVID.

Dr. Ulysses Wu, Hartford HealthCare’s chief epidemiologist, said 30 to 40 percent of all hospitalized COVID patients at his health system are incidental.

When asked if he thought more breakthrough cases could be going undetected, Wu said he suspects there are a far greater number of infections among the unvaccinated.

“There are definitely breakthrough cases that are not being detected, but I would suspect there is a greater number of unvaccinated cases that are not being detected, even more so,” he said.

Only two cases of the omicron variant have been confirmed in Connecticut, the vast majority of tested samples showing the delta variant.

“Delta is the demon that we’re dealing with at this point,” Wu said.

Though there have been some initial studies showing omicron is more transmissible, but less virulent than delta, that has not yet been confirmed.