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Flu Symptoms 2020: How to Avoid Getting the Flu?

There are lots of people who get vaccinated against the flu without understanding what they’re protecting themselves against. There are also many who don’t understand why vaccination isn’t always 100 percent effective. There are several different types of flu out there, and scientists do their best to predict which flu will be most harmful and protect the population from its unpleasant symptoms. 

There are four different strains of influenza viruses: A, B, C, and D. The ones that are discussed most commonly among the general public are influenza A and influenza B. These are the viruses responsible for the seasonal epidemics that occur every winter, also known as “flu season.”

Influenza A viruses are most known for their ability to cause pandemics (global epidemics of a disease). These pandemics are most likely to occur when the influenza strain that shows up is new and/or different from recent strains of the virus. When a new strain emerges, it has the ability to quickly and efficiently spread throughout the population.

Influenza A viruses are commonly divided into subtypes. These subtypes are based on two different proteins on the surface of the virus. The two proteins are hemagglutinin (H), of which there are 18 different subtypes (H1 through H18), and neuraminidase (N), of which there are 11 different subtypes (N1 through N11). The most commonly circulating influenza A viruses are H1N1 and H3N2.

The flu pandemic of 2009 was caused by an influenza A (H1N1) virus. That virus from 2009 has made some small genetic changes, but it continues to circulate seasonally today.

Influenza A (H3N2) viruses also routinely circulate and infect the population. These viruses are best known for their ability to change rapidly. These constant genetic changes can be much harder to predict and protect against.

Unlike influenza A, influenza B viruses are not divided into subtypes. B viruses are classified into two different lineages: B/Yamagata and B/Victoria. Typically, influenza B viruses are slow to change.

Vaccines are usually either trivalent (three-part) or quadrivalent (four-part). Scientists use data and surveillance research from over 100 influenza centers in over 100 countries to decide which virus strains to protect against.

This season, trivalent vaccines contain A/Brisbane/02/2018 (H1N1) pdm09-like virus, A/Kansas/14/2017 (H3N2)-like virus, and B/Colorado/06/2017-like (Victoria lineage) virus.

Quadrivalent vaccines contain all the viruses in the trivalent vaccine plus B/Phuket/3073/2013-like (Yamagata lineage) virus.

Flu season is officially underway, both in the United States and abroad. Lots of people want to know exactly when flu season starts, peaks, and ends, but the Centers for Disease Control and Prevention (CDC) reports that these time periods can change from year to year.

In the United States, the CDC reports that more than 170 million doses of the flu vaccine have been administered. There have been at least 29 million flu illnesses reported, 280,000 hospitalizations, and 16,000 deaths. The CDC believes that about 70 percent of flu cases were caused by influenza B and the other 30 percent, by influenza A. The CDC reports that the 2020 flu strain is unusual compared to the strains from previous years.

Flu symptoms, regardless of which strain is causing the infection, typically look similar. Both viruses are extremely contagious. It is nearly impossible to determine which strain is causing symptoms and illness without a lab test. Common flu symptoms include:

  • Fever
  • Fatigue
  • Chills
  • Body aches
  • Nasal congestion
  • Headaches
  • Cough
  • Sore throat

Vomiting and diarrhea are occasionally symptoms of influenza, but they usually only occur in children.

Typically, strains of influenza A appear earlier in the season, and influenza B strains appear later. Influenza B is slower to develop, which is why it shows up later. It is also more likely to affect children and younger adults as opposed to the elderly.

Interestingly, this year, most cases have been caused by influenza B, which usually shows up later in the season. The CDC believes this unusual change may be why more have suffered from flu symptoms this year.

If you are wondering whether your flu symptoms warrant a trip to the emergency room (ER), the answer is probably no. The ER is meant for those who are very sick. Flu symptoms, especially mild or early flu symptoms, are usually not severe enough for the ER.

There are some flu considerations you should keep in mind. If you have an existing condition or illness that your flu symptoms could make worse, call your doctor to check if you should go in for an appointment. 

If you are experiencing any of these severe symptoms, go immediately to the ER. Note that symptoms may be different in children than in adults. These lists are not all-inclusive.


  • Rapid/trouble breathing
  • Bluish tint to lips or face
  • Rib retraction when breathing
  • Complaints of chest pain
  • Indications of muscle pain (refusal to move/walk)
  • Dehydration (no urine for eight hours, no tears when crying)
  • Seizures
  • Fever greater than 104 degrees Fahrenheit that isn’t getting better with treatment
  • Decreased alertness or interaction
  • Fever or cough that gets better and then returns/worsens
  • Chronic medical conditions getting worse

Call the doctor immediately if a baby younger than 12 weeks has a fever.


  • Difficulty breathing or shortness of breath
  • Decreased urination/dehydration
  • Dizziness, confusion, decreased level of consciousness 
  • Seizures
  • Persistent chest or abdomen pain
  • Severe muscle pain
  • Fever or cough that gets better and then returns/worsens
  • Severe weakness or unsteadiness
  • Chronic medical conditions getting worse

Washing your hands might seem like trivial advice, but it is possibly the most important. When soap and water aren’t available, alcohol-based hand sanitizers are appropriate substitutes.

Avoiding crowds can feel impossible, but it is worth trying, especially for the more vulnerable population (sick and elderly). A respiratory virus like the flu can spread quickly in a crowd. If you know you are sick, stay home to prevent spreading your illness to others.

The flu virus spreads via respiratory droplets when people sneeze, talk, or cough. It can travel as far as six feet. Covering your mouth and nose with a mask protects you from inhaling the virus spread by others and prevents you from potentially infecting anyone else.

Sleep, diet, and exercise play a significant role in health and immunity. Although good habits can’t entirely prevent disease, a healthy body can fight infection much more efficiently.

While the many strains of flu can sound scary, it doesn’t help to worry. Stress and fear can actually have detrimental effects on your health and ability to fight disease. Instead, work hard to practice healthy routines for your physical and mental health. The best thing you can do to protect yourself is to get vaccinated, maintain a healthy lifestyle, practice good hygiene, and relax. You can fight off the flu and manage its symptoms better if you’re healthy.









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