Just in time for the new year, COVID-19 cases in Alaska have again begun to rise — and the highly transmissible omicron variant is likely responsible, according to state epidemiologist Dr. Joe McLaughlin.
New cases in Alaska rose 66% over a week-to-week comparison Wednesday, he said. Until last week, cases had been steadily declining for months following a deadly surge this fall.
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What do we know so far about the new omicron variant? What don’t we know?
The omicron variant, with its many spike protein mutations, appears to be more capable of immune evasion than other variants, McLaughlin said. That means that somebody who has had prior immunity from vaccination or a prior infection with a different strain of the virus may more susceptible to an infection.
Omicron also appears to be more transmissible than other variants, McLaughlin said.
“We’re still learning more and more about the transmissibility of this virus, but it appears to be able to bind more tightly to receptors in the cells on the surface of cells, and therefore making it more transmissible,” he said. While this hasn’t been proven definitively, it is likely the case, McLaughlin said.
There have also been a number of studies that indicate a possibly shorter incubation period. That means that a person may develop symptoms sooner than with other strains — within the first day and a half to three days, McLaughlin said.
Some promising data has shown that omicron may also be somewhat less virulent than other variants, meaning it may cause less severe illness. “That is possible, but we don’t know that for sure yet,” McLaughlin said.
What do we know about omicron in Alaska? How many cases have been identified so far?
Alaska has officially reported just six cases of omicron so far, but McLaughlin says there’s likely many more than that currently circulating.
A Christmas weekend storm in Fairbanks shut down the state’s public health lab for the week, halting sequencing efforts and causing a delay in reports. Despite that delay, McLaughlin said lab staff had noted that over half of a randomized batch of cases being sequenced last week had something called an “S gene target failure” that’s characteristic of the omicron variant and rarely seen with the delta variant.
Sequencing cases can take over a week, while “the S gene target failure is just a quick way to get a sense for what proportion of the cases we think are likely to be omicron,” McLaughlin explained.
The first two cases linked to the variant both involved people with travel history, earlier in December. Last week, four additional cases were reported, at least two of which involved people who hadn’t traveled out of state.
McLaughlin said that of Alaska’s identified omicron cases, one person was fully vaccinated and had received a booster shot, three were vaccinated but had not received their booster shots, one was unvaccinated and two were unreachable, so their vaccination status was unknown.
Three were symptomatic and none so far had been hospitalized, McLaughlin said.
How bad could omicron get in Alaska?
McLaughlin said the best way to estimate how omicron would play out in Alaska is to pay attention to how it moved through other states and countries that are already well into their omicron wave.
Omicron has spread rapidly through the U.S. in the world over the last month, with some states recording record single-day case counts, filling intensive-care units and overwhelmed testing sites. In some countries, omicron has surged and peaked relatively quickly.
In Alaska, factors like what percentage of the population has some prior immunity, the degree to which people comply with non-pharmaceutical interventions like masking and social distancing, and the degree to which workplaces, schools and congregate living facilities follow safety protocols would all influence how bad omicron gets in the state, McLaughlin said.
Alaska’s current vaccination rate is about 56.3%, reflecting the percentage of the total population that has completed the initial vaccine series — 33rd highest in the nation and about six percentage points below the national average.
How well do the vaccines work against omicron?
Preliminary data on how well vaccines work against omicron show lower vaccine effectiveness when compared to other variants — only about 30% to 40% effective at preventing infections, and 70% effective at preventing severe disease.
McLaughlin said that the good news, however, is that booster dose appear to “really help to improve immunity.”
The vaccines are likely closer to 75% effective at preventing infections for people who’ve been boosted, McLaughlin said.
What is the state doing to prepare for omicron?
McLaughlin said the state’s current focus is “ensuring Alaskans have access to testing, to vaccines, and to treatments.”
He said the state is also continuing to conduct contact tracing — but that it’s prioritizing those efforts on high-risk congregate settings, and that Alaskans are encouraged to notify their own close contacts if they do develop a COVID-19 infection. That will be increasingly important as more Alaskans continue to rely on at-home testing that doesn’t get reported to the state, he said.
“We’re also working to continue to support the health care system and provide timely communication,” McLaughlin said.