State reports small number of ‘breakthrough’ COVID-19 cases in fully-vaccinated Alaskans

Dr. Ellen Hodges tests a Bethel resident at a COVID-19 testing event hosted by the Yukon-Kuskokwim Health Corporation in Bethel, Alaska on Nov. 7, 2020. (Katie Basile/KYUK)

Alaska’s state health department reported Wednesday that 152 fully-vaccinated residents ended up testing positive for COVID-19 in February and March.

That’s just one-tenth of one percent of vaccinated Alaskans, said State Epidemiologist Dr. Joe McLaughlin. It’s roughly 2% of infections reported in Alaska since early January.

“If you’re vaccinated, you really dramatically decrease your risk of infection,” McLaughlin said during a call with reporters. “It’s very, very uncommon to have vaccine breakthrough cases.”

A “breakthrough case” is the term used to describe someone who has tested positive for COVID-19 at least two weeks after their final shot of the vaccine. The cases are being tracked across the country.

Louisa Castrodale, an epidemiologist with the state, said the small number of breakthrough cases tallied in Alaska isn’t surprising. The vaccine is extremely effective, she said, but it’s not perfect — no vaccine is.

“The vaccine doesn’t work 100%. So we’re going to see people who get sick with COVID who have been vaccinated,” Castrodale said. “We knew that.”

The goal is to get more Alaskans vaccinated so the state reaches “herd immunity” — a point where enough people are protected from the virus that it no longer spreads easily through the population.

Castrodale said what’s important to note about Alaska’s breakthrough cases so far is that about 60% never had any symptoms.

That’s because vaccinated people who become infected with COVID-19 are less likely to get very sick, compared to those who are unvaccinated. Also, they’re less likely to spread the virus to others, Castrodale said.

“Those individuals don’t necessarily present the same infectious risk to others who have not been vaccinated,” she said.

Most of the 152 breakthrough cases in February and Mach tested positive during routine testing for travel or work, or before medical procedures, said Castrodale.

The median age of the Alaskans is 51.

Among the 152 cases, one Alaskan with multiple, long-term chronic conditions was hospitalized, according to the state’s report. Shortly after the positive result, the person took a second test and was negative.

Another Alaskan, who was older than 65 and had several chronic conditions affecting various organ systems, tested positive for COVID-19 and died about two weeks later, said Castrodale.

“It’s the reason why we just want to prevent as much COVID as possible, because there are those fragile people who have systems that really can’t take COVID,” she said.

Castrodale and other health officials on Wednesday underscored that the vaccine is the best protection from the coronavirus.

They called on more Alaskans to get vaccinated, not only to protect themselves but to also drive down the number of coronavirus cases in the state, and protect others.

“The less COVID we have circulating, the less breakthrough cases we’ll see,” said Dr. Anne Zink, Alaska’s chief medical officer.

As of Wednesday, about half of Alaskans age 16 and up had gotten at least the first vaccine dose.

The state health department also reported another 181 Alaskans diagnosed with COVID-19 on Tuesday, with 45 patients in the hospital with the illness.

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