By Dr. Carol Hoban
Faculty Member, Health Sciences
In the United States, flu season occurs in the fall and winter. While influenza viruses circulate year-round, most of the time flu activity peaks between December and February but can last as late as May, according to the Centers for Disease Control and Prevention (CDC).
Influenza activity for the 2020-2021 season reached historically low numbers in the United States. The number of respiratory specimens that tested positive across the country was down 2.3% from typical seasons which averaged greater than 20%, as reported by the CDC.
With the introduction into the U.S. beginning in February 2020 of SARS-CoV-2, the virus that causes COVID-19, established mitigation measures helped retard the spread of COVID-19. Such measures included business closures, mandatory stay-at-home policies, schools converting to online learning, social distancing, sanitizing hands and surfaces, and wearing face masks.
These measures, along with traditional influenza vaccinations, have contributed to the record low numbers of the flu virus nationwide and may help to further reduce cases in future flu seasons if some of these same mitigation measures are practiced.
How Flu is Transmitted
The influena virus is mainly spread through droplet transmission when someone infected with the virus sneezes, coughs or even talks. Influenza can be spread before a person begins showing symptoms and the virus is most contagious during the first three or four days after becoming ill.
Previous studies examining flu transmission have estimated that around 8% of the U.S. population becomes infected with the influenza virus and becomes ill each flu season. Children are the most susceptible to the flu, while persons over 65 are the least susceptible.
However, there are many complications from influenza, such as pneumonia. Also, the virus can further exacerbate pre-existing conditions like asthma or heart disease. The influenza vaccine is still the most effective way to prevent the flu each season.
With the introduction of many mitigation measures to help stop the spread of the COVID-19 pandemic, transmission of the influenza virus was nearly halted as historically low numbers of the flu were reported.
During the 2020-2021 influenza season, the CDC reported around 2,000 confirmed flu cases from September 2020 to June 2021. However, during the 2019-2020 influenza season, the CDC estimates 38 million people contracted the flu resulting in 22,000 deaths.
Wearing Masks and Social Distancing Can Reduce Future Flu Cases
With this dramatic reduction in flu cases, these mitigation measures might be helpful in the upcoming influenza season along with the continued efforts to administer the influenza vaccination. Taking additional steps, such as wearing a mask, social distancing, and even staying home to protect the most susceptible groups from the flu and the possible resulting complications, might continue to reduce the number of future cases, hospitalizations or even deaths in the coming 2021-2022 flu season.
These measures can be an important part of public health education during the upcoming flu season especially for the most vulnerable groups. In addition to getting their annual flu shot, these groups can take the additional measures to protect themselves, their families, friends and loved ones and further reduce their chances of becoming ill.