8 fully vaccinated Mainers have died from COVID-19. Vaccines still prevent more deaths.

Jun. 13—When Karen Letourneau saw her mother in April for the first time in more than a year, she did not expect it would be the last time.

Three weeks earlier, Letourneau's mother, Patricia Caron of Lewiston, had received the Johnson & Johnson vaccine. The day they met, Caron felt symptoms of what she thought was a cold. But when Letourneau, who lives in Wales and was partially vaccinated then, found herself experiencing COVID-19 symptoms a few days later, she asked her mother to get tested.

Caron got a rapid coronavirus test. It came back positive. She ended up in the hospital and died of COVID-19 complications a few weeks later, her daughter said, becoming one of eight fully vaccinated Mainers to succumb to the disease.

These so-called breakthrough infections are rare, Maine Center for Disease Control and Prevention Director Nirav Shah said last week. The state has identified 426 cases of the virus in fully vaccinated people, accounting for about 1 of every 1,600 vaccinated people in Maine. By comparison, more than 15,000 Mainers, or 1 out of every 88 people, have tested positive for the virus in the past two months alone.

Those numbers fit with scientific studies showing the vaccines used in the U.S. are more than 90 percent effective. But the deaths are tragedies for families who assumed vaccines would eliminate COVID-19 risk and raise concerns among people with compromised immune systems and their loved ones.

Health officials still emphasize that vaccinations are still the best way to stop the spread of the virus and prevent severe disease and are optimistic that Maine's high overall vaccination rate will continue to reduce transmission, including breakthrough cases.

The initial data suggest breakthrough cases in Maine are more common in older individuals and people with underlying health conditions, Shah said. Almost all are not serious. About half of vaccinated people who tested positive for COVID-19 were not experiencing symptoms when contacted by a case investigator, according to the Maine CDC. Only 19 have been hospitalized.

Importantly, breakthrough cases have not been associated with one COVID-19 vaccine more than others, Shah said, nor have they been linked to particular variants. He said people who tested positive for the virus after being vaccinated were exposed in a variety of ways.

Because vaccines work by stimulating an immune response, they can be less effective for those with weakened immune systems, such as organ transplant recipients or chemotherapy patients, said Dr. James Jarvis, who leads Northern Light Health's COVID-19 response.

Jarvis emphasized, however, that vaccines are still incredibly helpful for immunocompromised people, who also tend to be at greater risk for severe COVID-19.

"If I told you that you had a 90 percent chance — if you came down with COVID-19 — that you would be severely ill if you were unvaccinated, but you only have a 50 percent chance if you are vaccinated, then vaccines make a huge difference for you," he said. "So it is important for people to remember that even if your immune response is less than what it is for the general population, it's still better than not being vaccinated at all."

From a public health perspective, Jarvis noted that there is increasingly strong evidence that vaccines limit spread of the virus. A U.S. Centers for Disease Control and Prevention study released last week found vaccinated health care workers who contracted COVID-19 carried lower viral loads and shed less virus, making them less likely to transmit it to others.

That suggests widespread vaccine uptake can still reduce breakthrough cases in immunocompromised people by making them less likely to be exposed to the virus in the first place. Maine has started to see the effects of high vaccination rates on transmission in the past month, with cases and hospitalizations declining rapidly. Sixty-four percent of Mainers have now received at least one vaccine dose, according to federal data.

Letourneau, whose mother died from the virus despite being vaccinated, said she wishes there was more information available about breakthrough cases. If she had known more, she said, she would have taken more precautions despite her mother's vaccination status and been more insistent that she seek testing and treatment when she first had symptoms.

Caron was previously undergoing pulmonary testing due to shortness of breath and took an immune-suppressing medication to treat rheumatoid arthritis, Letourneau said. She wonders if that could have led the vaccine to work less effectively. But she is also frustrated by discourse about breakthrough cases, saying people were too often dismissive of potential risks for older people and those with pre-existing conditions.

"It almost gets mentioned as an aside, like the people who this happens to are the elderly and the immunocompromised, so it's like they don't matter as much," she said. "But they do matter."