10 Things You Should Know About the Flu
The flu is a contagious respiratory illness that causes symptoms like fever, cough, chills, body aches, and fatigue. It spreads easily—especially in schools and workplaces—and flu season returns each year like clockwork.
While many people recover in one to two weeks, the flu can be dangerous, especially for young children and adults over 65. Some complications can even be life-threatening.
Understanding the flu helps you take better steps to protect yourself and others. Here are 10 important facts everyone should know:
1. Flu season runs from October to May
Many people associate the flu with winter, but it can strike as early as October and last into May. Peak activity often happens in the colder months, but don’t let your guard down in the fall or spring.
2. You can spread the flu before symptoms appear
The flu is contagious up to a day before symptoms start. You’re most contagious during the first 3–4 days of illness but can continue spreading it for up to a week. This is why early prevention is key.
3. Symptoms can hit suddenly
Flu symptoms often come on fast. You might feel fine one day and completely drained the next. Symptoms can appear as soon as a day after exposure or take up to four days to develop.
4. The flu vaccine takes two weeks to kick in
It takes about 14 days after vaccination for your body to build immunity. That’s why it’s best to get your flu shot early in the season—ideally by the end of October.
5. You need a new flu shot every year
Flu viruses evolve constantly, which is why vaccines are updated annually. A shot you got last year won’t protect you this year—stay current for the best protection.
6. The flu vaccine won’t give you the flu
Despite the myth, the flu shot doesn’t cause the flu. Some people experience mild side effects like low-grade fever or soreness, but these symptoms are not the same as having the flu.
7. The flu can lead to serious complications
Certain groups are more vulnerable, including:
- Adults 65 and older
- Young children under 2
- Pregnant and postpartum women
- People with chronic conditions or weakened immune systems
- Native Americans
- Individuals with extreme obesity (BMI ≥ 40)
Complications range from sinus or ear infections to life-threatening conditions like pneumonia, sepsis, or heart problems.
8. You can still get the flu after being vaccinated
No vaccine is 100% effective. You might get sick if you’re exposed before your immunity builds or encounter a strain not covered by the shot. Still, the flu shot reduces illness risk by 40–60% on average and often leads to milder symptoms if you do get sick.
9. There are different types of flu vaccines
Flu vaccines aren’t one-size-fits-all. Options include:
- Trivalent: protects against three strains
- Quadrivalent: protects against four strains
Some versions are approved for kids as young as 6 months, while others are designed for adults or seniors. Your doctor can help choose the right one for you.
10. Egg allergies usually aren’t a problem
If you’re allergic to eggs, you can likely still get the flu shot. Some vaccines are egg-free, and medical professionals can safely monitor for reactions if needed. Talk to your doctor about your options.
Bottom line
The flu can be mild—or it can turn serious. The more you know about how it spreads and how to prevent it, the better equipped you are to protect yourself and your loved ones.