Health experts agree that when it comes to monitoring the annual influenza season, the only common denominator is how unpredictable it is.
The timing, severity and length of the season varies each year. Seasonal flu activity often begins as early as October, usually peaks between December and February, and can last as late as May.
Every year, the Centers for Disease Control and Prevention (CDC) monitors the severity of the influenza season based upon three indicators:
- The percentage of visits to outpatient clinics for influenza-like illness (ILI)
- The rates of influenza-associated hospitalizations
- The percentage of deaths resulting from influenza or pneumonia.
The CDC classified last year’s flu season as moderate overall. By comparison, the 2017-18 season was classified as high and the 2016-17 season was classified as moderate.
Ben Cannon, public health administrator for Curry Community Health, said the 2018-19 season seemed to peak later in the season (February through March), while previous seasons peaked from December to January.
The rise in ILI was similar to the 2017-18 season, Cannon said. He said Curry County’s numbers tended to follow the national and state averages, which was classified as average ILI last year.
According the Oregon Health Authority, there were no influenza-related deaths among the adult population, and five among the pediatric population, through May of the 2018-19 season.
With so many unpredictable elements, there are standard guidelines local officials follow.
“We recommend receiving the flu vaccine before the end of October and have scheduled the majority of our field clinics during this time to help our community meet this recommendation,” said Shelby Bodenstab, senior certified public health nurse at the Del Norte County Department of Health and Human Services.
Bodenstab said that from 2013 to 2018, Del Norte County had no reported cases of influenza-associated deaths. She added, however, that county-specific data regarding other indicators, such as hospitalizations or medical visits for influenza-like symptoms, were unavailable.
To ensure there are enough flu vaccines for an unpredictable season, the CDC reported that manufacturers have projected they will provide 162 million to 169 million doses in the U.S. This is similar to the projected supply for last season, the CDC said.
Another constant each flu season is who should get a vaccine. Both Bodenstab and Cannon stick to CDC guidelines:
- The flu vaccine is recommended for everyone age 6 months and older.
- Adults ages 65 and older should receive the high-dose flu vaccine, which contains four times the amount of antigen as a regular flu shot.
- Some children between ages 6 months and 8 years will need two doses of flu vaccine this year.
“We very much recommend parents to connect with their child’s primary-care provider as soon as possible in order to receive the second dose by the end of October,” Bodenstab said.
Even with a flu shot, health experts agree it is still possible to become symptomatic afterwards. And while subtle, there are differences in symptoms between the common cold and the flu (see chart). The biggest difference being the speed of the onset of symptoms — colds tend to be more gradual while the flu is more abrupt.
Bodenstab said people who are already experiencing mild flu-like symptoms usually recover in less than two weeks and do not need additional medical care or antiviral drugs.
Those who are at high risk of flu complications or are concerned about their illness should be treated by a doctor.
Bodenstab said the flu vaccine won’t help to treat any of the symptoms of the flu. It helps prevent illness and decrease the severity.
Also, it typically takes about two weeks to develop immune protection. “It is possible, however, to become ill from more than one strain of influenza in a season,” she said.
“This is why vaccines typically guard against three or four strains, and each time you contract the flu you are at just as great a risk for potential complications, such as pneumonia or sepsis.”
The CDC said flu vaccines protect against the three or four most common viruses. For 2019-20, trivalent (three-component) vaccines are recommended to contain Brisbane and Kansas A-strains viruses and the Colorado B-strain virus.
Quadrivalent (four-component) vaccines, which protect against a second lineage of B viruses, contain additional protection against the Phuket B-strain virus in addition to the other three.
Bodenstab said mild reactions are expected after receiving the flu vaccine. The most common side effects are soreness, redness, tenderness or swelling at the site of the vaccine. A low-grade fever, headache and muscle aches may also occur.
She said that even if you've had the flu or think you might have had the flu, it's important to get your flu shot if you haven't had one already this season.
“Getting the flu shot also has other benefits besides keeping you from getting sick with the flu,” she said. “It reduces the severity of the illness if you do get sick with the flu. It also can reduce the risk of flu-associated hospitalizations, and prevent serious medical events for those with heart disease, diabetes and chronic lung disease.
The flu shot also helps protect women during and after pregnancy and can protect a baby after birth from the flu.
According to Bodenstab, getting a flu vaccine also protects those around you, especially those who are the most vulnerable to the flu — babies, older adults and people with chronic health conditions.
Bodenstab said it is important to differentiate between influenza and the “stomach flu,” which is used to describe nausea, vomiting or diarrhea. “The flu is a respiratory disease and not a stomach or intestinal disease,” she said.
Public Health is offering the Fluarix Quadrivalent vaccine, which is developed to protect against the four recommended influenza strains that have been projected for the 2019-2020 flu season.
In Oregon, people 18-years and under, and under-insured or uninsured individuals, or American Indians-Alaskan natives, could qualify for the free vaccination.
Pharmacies offer a variety of flu vaccine. Many times these are covered by insurance, and are designed to be a quick and convenient public-access process.
Family and pediatric providers also offer the flu vaccine throughout the flu season. Parents should consult with their child's provider regarding the flu vaccine to determine vaccine history and how many doses their child will need. Those with certain concerns regarding the flu vaccine or reactions should also consult with their providers.
To learn more about the 2019-20 flu season, go to the CDC webpage on frequently asked questions at https://bit.ly/33dtWgY. To contact the Oregon Health Authority, call 971-673-2315. To Contact Curry County Health, call 541-247-3387.