The percentage of Alaska children who are up to date on their routine vaccinations has fallen considerably since the beginning of the pandemic, prompting concern among health experts about the return of certain serious illnesses that had been all but eradicated in the U.S. until recently.
Although there have been no outbreaks of vaccine-preventable illnesses — including measles, mumps or polio — identified in Alaska so far, recent flare-ups of those diseases in the Lower 48 and multiple countries are part of a disturbing trend that epidemiologists have linked to lower vaccine coverage during the pandemic.
Routine childhood immunizations for diseases such as hepatitis A and B, diphtheria, tetanus, polio and the flu are an important way of priming a child’s immune system to protect them against potentially deadly illnesses from an early age, said Dr. Anne Zink, Alaska’s chief medical officer. When uptake is high enough, vaccines help eradicate diseases.
“Vaccines have been the core public health success of the last 100 years,” she said.
For polio, the World Health Organization recommends 95% vaccine coverage to control the disease.
In Alaska, by June 2018, 65% of children between 19 and 35 months old had received their recommended shots.
By June 2020, that rate had fallen to around 61%, and by June 2021 it hit a low of 51%, according to data from the Alaska Department of Health. By June 2022, that number had rebounded just one percentage point, to about 52% coverage among younger children.
That drop is concerning, said Dr. Joe McLaughlin, Alaska’s state epidemiologist.
“Even a transient decline in vaccine coverage can compromise herd immunity and result in propagation of outbreaks such as measles,” he said.
“It’s particularly concerning that it’s been sustained now,” he added, noting that while some states have seen a larger rebound in vaccine coverage in recent months, Alaska has not.
Vaccines are typically created for diseases that are associated with higher morbidity rates and increased likelihood of outbreaks.
Zink said a big concern for her is the possibility of a polio outbreak, which the state is unprepared for.
“I have never seen a case of polio in my clinical career, ever,” she said. “But even our testing mechanisms or training for providers — this has been a disease has been essentially eliminated in the United States and in most of the world. And so just even having clinicians think about and to recognize this disease and to test for it would be really, really challenging.”
Until June of this year, no sustained community transmission of polio had been detected in the United States for decades.
The last U.S. case of the virus was confirmed in 1979, and in 1994, the World Health Organization declared the region polio-free as a result of an effective vaccine given to young children.
Then in June in New York, a previously healthy man in his 20s was hospitalized with fever and leg paralysis before testing positive for polio. Wastewater sampling showed evidence the virus that causes polio has been circulating in New York for months. Cases have also now been detected in Israel and London.
“This is our first big flare-up, as a world, of polio since this huge effort for polio eradication,” Zink said. “It’s enough of a signal to make us concerned that we might be getting towards that tipping point, and we’re gonna have to think about what that means and what are we going to do.”
McLaughlin said that while it was difficult to know the exact reasons why vaccination rates in Alaska had fallen, survey data and research in the Lower 48 pointed to factors like a rise in telemedicine over in-person visits, decreased vaccine confidence and decreased enforcement of vaccination by school districts during periods of virtual learning.
“I think that the reasons why are very nuanced,” Zink said. “I think the thing that we can do from a public health perspective is look at why people are getting vaccinated, and why they’re hesitant.”
Zink said she often hears from both patients and providers that convenience often plays a role in Alaskans’ decision to get vaccinated, and the solutions to the problem must include making it easier and less expensive for families to access shots.
Developing trusted relationships with health care providers and learning from Alaska Native communities — who typically have among the highest vaccination rates in the state — are also important, she said.
McLaughlin said he’s hopeful that Alaska will soon see a rebound in vaccination coverage, as other states have experienced.
“We really encourage health care providers to use their electronic health records ... to identify children who have missed their recommended vaccinations. And then contact the parents to schedule in-person appointments to get their children caught back up,” he said.