Health officials predict potentially more potent flu season ahead
Because influenza levels were so low last year, people have developed a reduced immunity. That means the upcoming season could be early and possibly severe.
Janelle Delgadillo, an analytical epidemiologist at the Utah Department of Health, said influenza was largely reduced because of prevention measures against COVID-19 last year, but the virus will most certainly return this year now that pandemic restrictions have relaxed.
“There’s a lot we don’t know about the upcoming 2021-2022 flu season,” she said. “However, we do know that multiple respiratory viruses will be circulating in the community this fall and winter. The circulation of multiple viruses could place a renewed high burden on the healthcare system.”
Lynette Brammer, an influenza expert at the Centers for Disease Control and Prevention said antibodies that protect against the flu wane over time.
“Because there was little flu virus activity last season, adult immunity, especially among those who were not vaccinated last season, will now depend on exposure to viruses two or more seasons earlier,” she said. “Young children also will have lower immunity to flu. As children return to school and potentially get infected, there could be a higher number of children with no prior exposure to flu and therefore lower immunity which could increase illnesses.”
This lack of exposure to more recently circulating viruses underscores another important reason to get vaccinated against influenza this season, Brammer said.
Amy Carter, nurse epidemiologist for the Weber-Morgan Health Department, said while it’s hard to predict what kind of flu season awaits the public, a lot will depend on people’s actions.
“We recommend that it’s important and maybe even more important this year that people go and get the vaccine,” she said. “It’s also really important for people to stay home if they’re sick, wash their hands and cover their cough and sneezes.”
Last year’s flu vaccine expired in June. Health officials say the recommended time to get the vaccine is between September and October. Brammer said getting vaccinated too early, however, is likely to be associated with reduced protection against flu infection later in the season, particularly among older adults.
“Children who need two doses should start the vaccination process sooner, because the two doses must be given at least four weeks apart.” she said.
Influenza is an infection of the nose, throat and lungs and is easily spread from person to person, Delgadillo said. There are different types of flu viruses, but the most common are influenza A and influenza B.
“There are also different strains of each type of virus. This information is important so scientists can develop the best flu vaccines for each flu season,” she said.
Although fewer influenza viruses were available to inform the influenza vaccine selection process for the 2021-2022 season, Brammer said the CDC does not think this will affect the match between circulating viruses and vaccine viruses, because the viruses that were circulating were well sampled.
With COVID-19 on the rise again, it may be difficult to recognize which illness you have because many of the symptoms overlap, including fever, chills, cough, shortness of breath, fatigue, sore throat, runny or stuffy nose, body aches, headaches, vomiting and diarrhea. Both illnesses may also cause a change in or loss of smell or taste, although this is more common with COVID-19, according to Delgadillo.
“COVID-19 may cause more severe illness in some people. Children and adolescents may also develop a rare but severe complication as a result of a COVID-19 infection, known as multisystem inflammatory syndrome,” she said. “Children, especially those younger than 5 generally have a higher risk of serious complications from flu compared to COVID – 19. However, COVID-19 may still result in hospitalization and death in young, healthy children.”
This year’s vaccine will protect against H1N1 and H3N2, which are both influenza A strains, plus B/Victoria and B/Yamagata.