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As winter approaches in Minnesota, so does the annual flu and respiratory virus season. St. Olaf College Visiting Instructor of Nursing Kris Ehresmann explains why seasonal flu and COVID-19 vaccinations are important, who should receive them, and how they help protect individuals and communities.  

What is the purpose of seasonal vaccines, and who should receive them?
In Minnesota, we see influenza and other respiratory viruses circulate widely in the late fall and winter months each year. Each season’s severity is unpredictable, and the best way to prepare for any season is to be vaccinated. Seasonal fall vaccines provide protection against influenza and SARS-COV-2 (the virus that causes COVID-19), preventing illness and, more importantly, preventing hospitalization and death.  

The annual influenza vaccine is recommended for all individuals older than six months of age. The annual updated COVID-19 vaccine is recommended for all young children ages 6-23 months and children 2-18 years in certain risk groups, such as those who are immunocompromised or have chronic conditions, or if desired. Adults ages 19 to 64 should receive an annual updated COVID-19 vaccine. For adults ages 65  and older, an annual updated COVID-19 vaccine is recommended, followed by a second dose six months later to boost protection. 

It is safe to receive the influenza vaccine and the COVID-19 vaccine at the same time.   

How often should people receive COVID-19 and flu vaccines? Why do recommendations change from year to year?
In general, COVID-19 and influenza vaccines are administered annually. Because these viruses can mutate, the vaccines need to be updated each year to provide protection against new strains that have developed. In addition, vaccine protection can wane over time, so annual vaccination helps ensure your body has built up protection before you get sick. 

However, some age groups may need two doses in a year. These include children receiving their first influenza vaccine or persons over the age of 65, who may need a second COVID-19 vaccine to boost their protection.

What are the health benefits of annual vaccinations, and what common misconceptions should people be aware of?
Vaccination reduces the risk of influenza- and COVID-19-related illness, hospitalization, and death. While the influenza and COVID-19 vaccine won’t prevent every infection, it is the best way to reduce your risk of severe illness and its complications. 

According to the Centers for Disease Control and Prevention (CDC), flu vaccination prevented an estimated 10 million flu illnesses, five million medical visits, 180,000 hospitalizations, and 12,000 deaths during the 2024–25 flu season. Influenza vaccination has been shown to reduce the risk of seeking medical care for flu by 40–60 percent. Beyond preventing influenza, vaccination also reduces the risk of major cardiovascular events, including heart attacks and strokes, among adults with cardiovascular disease. 

During pregnancy, influenza vaccination reduces the risk of influenza-related emergency department and urgent care visits by half—and it protects the baby too! When their parents were vaccinated during pregnancy, influenza-related hospitalizations among infants under 6 months old decrease by one-third, while emergency department visits among infants younger than 3 months decrease by half.

COVID-19 continues to cause millions of illnesses, hundreds of thousands of hospitalizations, and tens of thousands of deaths each year in the United States. It was the tenth leading cause of death in 2023. Extensive clinical studies and real-world data show that COVID-19 vaccination significantly reduces the risk of severe illness, hospitalization, death, and long COVID. Vaccination during pregnancy provides critical protection to newborns, reducing COVID-19-related hospitalizations by approximately 54 percent during the first three months of life. 

One of the most common misconceptions about influenza vaccination is that the vaccine can cause the flu, which is not true. Neither the injectable vaccine nor the nasal spray vaccine can cause influenza. The inactivated injectable influenza vaccine contains only killed virus fragments, and the recombinant vaccine contains only a part of the influenza virus. The mRNA vaccine contains only mRNA to help the body make just one influenza protein, but not the whole virus. The nasal spray influenza vaccine contains weakened viruses that may produce mild, cold-like symptoms, but cannot produce influenza disease. 

Similarly, people cannot contract COVID-19 from the vaccine. Licensed COVID-19 vaccines do not contain the live virus. Instead, they use mRNA or harmless protein components to teach your body to recognize and fight the virus. These ingredients cannot cause a COVID-19 infection. 

Side effects such as low-grade fever (99.1–100.4°F), chills, fatigue, or muscle aches are common with vaccinations. These symptoms are signs your body’s immune system is building protection, not that you are sick with influenza or COVID-19.

Besides getting vaccinated, what are other sanitary and prevention practices people can enact during the flu and cold season?
Most of the recommendations are things you have heard before and should continue to do: 

• Cover coughs and sneezes. Cough or sneeze into your elbow or use a tissue to cover your nose and mouth—throw the tissue away after you use it and wash your hands. 
• Wash your hands frequently. Use soap and water, especially after you cough or sneeze. If you are not near water, use an alcohol-based hand sanitizer. 
• Avoid close contact with people who are sick. If you become ill, protect the people around you by staying home from work or school until your symptoms are improving and you have been fever-free for at least 24 hours without fever-reducing medication.
• Avoid touching your face. Viruses can spread when you touch your eyes, nose, or mouth. 
• Consider wearing a high-quality mask. Wearing a well-fitting face mask or N95 respirator, especially in crowded public spaces when respiratory viruses are circulating, can reduce the risk of catching or spreading respiratory viruses, including influenza. 

How does your work at St. Olaf help prepare the next generation of health professionals?
I teach “Introduction to Public Health” and “Epidemiology” within St. Olaf’s public health concentration. Last January, I also taught a course focused on vaccines. Through these courses, I hope students develop a deeper understanding of how public health protects and improves the health of entire communities—not just individual patients.

Whether students go on to careers in medicine, nursing, public health, research, or other fields, I want them to recognize the important role that prevention, evidence, and population health play in creating healthier communities. 

Most importantly, I hope they gain the knowledge and confidence to use evidence to make a difference in the lives of others.

About Kris Ehresmann
Kris Ehresmann is a member of the public health faculty at St. Olaf College. Before St. Olaf, she served as the director of the Infectious Disease Epidemiology, Prevention and Control Division at the Minnesota Department of Health until her retirement in February 2022. 

Ehresmann has led numerous outbreak investigations, including Minnesota’s COVID-19 response, published research in peer-reviewed journals, and served as an invited speaker at national meetings. She also served on the federal Advisory Committee on Immunization Practices from 2018-2012 and was a voting member of the National Vaccine Advisory Committee from 2020-2025.