The flu season is an annually recurring time characterized by relative outbreaks of influenza,commonly referred to as the flu. The season occurs during the cold half of the year in each hemisphere. Influenza activity can be predicted and even tracked geographically in some places.
Three virus families, A, B and C, are the main infective agents that cause the flu. During long periods of cool temperature, influenza cases can increase drastically.
“Each annual flu season is normally associated with a major sub type,” Saddleback College physician Dr. Sonya Murray said. “The associated sub type changes each year, due to development of immunological resistance to a previous year’s strain through exposures and vaccinations, and mutational changes in previously dormant strains.”
An influenza vaccine is recommended for everyone six months of age and older, and is especially important for infants, young children, pregnant women, adults over 50 and for those with chronic medical conditions. Flu vaccines protect against the three aforementioned viruses which commonly cause disease each year. The three viruses are influenza A (H1N1), influenza B (H3N2), and influenza C.
“While there have been reports nationally of influenza H3N2 strains causing illness that are derived from the vaccine strain, this is just one of multiple influenza viruses seen so far this season,” Murray said. “In situations when there is an imperfect match to one virus, vaccination provides protection against other strains which may be circulating.”
The exact causes of the seasonal nature of influenza outbreaks are unknown, but there are some possible explanations. People are often indoors during the winter, meaning that they are in direct or close-contact with one another more often. This promotes a higher likelihood of transmission.
“Cold temperatures lead to drier air, which may dehydrate a person’s mucous membranes, preventing the body from effectively defending against influenza virus infections,” Director of Internal Medicine at OptumCare Medical Group Dr. Gregory Joy said. “Viruses are preserved in colder temperatures due to slower decomposition rates, so they live a lot longer on exposed surfaces such as doorknobs, counter tops or things often touched by people.”
The Saddleback Student Health Center urges people to get vaccinated much sooner than later. In the section titled “Notes and Notices from the Student Health Center” on the Saddleback College website, the Health Center makes recommendations.
“It’s important to practice good hand washing and other good health habits. People who are ill should take actions to stop the spread of germs So make sure you stay home if you are sick, cover your nose and mouth when coughing or sneezing, wash hands thoroughly with soap and water or use an alcohol-based hand sanitizer and avoid touching your eyes, nose and mouth too frequently.”
The Centers for Disease Control and Prevention estimates the true burden of flu illness in the United States, including total flu cases, by using a mathematical modeling system in combination with data from these traditional flu surveillance. The CDC website estimates that the flu has resulted in between 9.2 million and 35.6 million illnesses each year in the United States since 2010.