The flu season has come: what you need to know about the flu vaccine

It's the beginning of autumn, which means that the flu season has arrived.

Last year, the number of hospitalizations related to influenza was the highest ever recorded; 106 out of every 100,000 people were hospitalized for influenza during the 2017-2018 season, with people over 65 accounting for 58% of these hospitalizations and 180 pediatric deaths.

The flu and colds can make you feel bad, but they are caused by different viruses. Colds are usually lighter and do not lead to serious health problems associated with the flu, such as pneumonia or hospitalizations.

Right now, preparation is the best thing to do before the season. Here's what you need to know.

When does the flu season begin?

The flu season can begin in October in North America, but usually starts in the fall and ends in March. However, the flu virus can be detected at any time of the year. It is therefore important to know if you have symptoms, even in summer. Experts can not really predict the severity of each influenza season, as different strains of the virus can have different impacts on the timing and duration of the season.

Should I get the flu shot? When?

Yes. With a few exceptions, the Centers for Disease Control and Prevention recommends that people aged 6 months and older be vaccinated each year. This is the first line of defense in the treatment of influenza. Although people who suffer from moderate or severe illness must wait to recover before being vaccinated. Only people with serious, life-threatening allergies to the vaccine or any of its ingredients should avoid the vaccine. According to the CDC, anyone between the ages of 2 and 50 should receive either the shot or the nasal spray. The American Academy of Pediatrics, however, says the flu shot is the preferred choice over nasal spray for kids

You can get vaccinated at any time as the fall approaches, but October is probably the best time to do it. The CDC recommends everyone to get vaccinated by the end of October, which will give your body the period of about two weeks that it needs to develop an immune response to the vaccine before the start of the flu season. If you miss this time, the vaccine may still offer some benefits. It is therefore important to get it as long as people get sick.

What if I'm pregnant?

It is strongly recommended that all pregnant women be vaccinated against influenza. The body changes during pregnancy – heart rate and oxygen consumption increase as lung capacity decreases. This means that if a future mother gets the flu, she is more likely to have life-threatening complications than the general population. Therefore, all women who are pregnant or likely to be pregnant should be vaccinated against influenza. This is all the more important since a recent CDC study showed that only half of pregnant women receive the vaccine.

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I've heard that the flu shot makes you sick. Is it true?

The influenza vaccine contains an inactivated virus, which means that the virus in the vaccine can not really infect you. It takes one to two weeks for your immune system to protect you from the flu. Thus, if a person gets sick after shooting, it is probably because his body is not yet protected from the flu, and not the vaccine itself.

Similarly, there are sometimes mismatches between a person's viral strain and the strains used to make the vaccine. In these cases, the vaccine might be flawed to fight against all existing strains of flu, but it's still our best defense.

How do I know if I have the flu?

The symptoms of the flu often occur suddenly and can vary considerably from person to person. These include fever, cough, sore throat, nasal congestion, body aches, headache, and fatigue. Although the flu may seem like a cold, colds are usually slower to develop and less likely to cause fevers.

Some patients with severe infections may have symptoms, such as difficulty breathing and confusion, which are of concern and may require immediate medical attention to treat them. Medical attention should also be sought for children with the flu who develop bluish skin, do not wake up, or do not eat. In any case, if the person's symptoms worsen suddenly after appearing to improve, a visit to a clinician is warranted.

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I think I have the flu. What do I do next?

In most cases, if the symptoms are mild, it is best to stay at home and only leave for treatment. If you must leave the house, wear a face mask, wash your hands and cover your cough and sneezing with your elbow.

People with severe symptoms, as well as people at high risk of influenza (young children, people aged 65 and over and pregnant women) should contact their doctor if they develop symptoms. In some cases, people can get antiviral medications, which can reduce symptoms, reduce the time of illness and reduce complications.

How is shooting done?

Manufacturers have many methods of producing flu shots. The most common method is the egg-based vaccine, in which strains of the virus are injected into eggs and incubated for several days. They are then weakened or killed and then purified for use in a shot or nasal spray.

The following method uses cellular technology. In these vaccines, the eggs used to incubate the virus are replaced by animal cells. This method produces vaccines faster than the older egg-based method.

Another method uses recombinant technology. In these cases, a certain gene is taken from the influenza virus to be inserted into another non-influenza virus that develops in the insect cells. This genetically modified non-influenza virus then replicates in insect cells. After virus replication, manufacturers purify the protein produced from the influenza gene, which is used in the vaccine. The advantage of this method is that it does not use eggs. Thus, people with severe allergies to eggs can be vaccinated.

For all these methods, the FDA must test and approve the vaccines before they are published.

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What are the side effects of the influenza vaccine?

Most side effects are mild and disappear quickly. The pain in the firing zone is quite common. In addition, people can have headaches, fever and nausea. Seek immediate symptoms if a person shows signs of a serious allergic reaction, such as difficulty breathing, hoarseness or swelling of the eyes and lips.

Where should I get the flu shot?

Grocery stores, pharmacies, medical offices and hospitals all offer flu shots. Experts say that no matter where you get it, as long as you get it.

The flu season is here. Preventing its spread requires good hygiene and high vaccination rates. If you experience symptoms, avoid contact with other people. If symptoms start to worsen, contact your doctor. Working together will be essential to ending the flu season.

Dr. Jonathan Steinman is a radiology physician and writer at ABC News Medical Unit.