The flu season is well underway and it is not too late to get vaccinated.

Centers for Disease Control and Prevention reported Friday that between 6 and 7 million people had contracted the flu so far this season, and that nearly half of those needed medical care for their illness.

While this may seem like a lot, this season's numbers are much more in tune with typical influenza season trends, a difference from last year, when influenza hospitalizations were the highest ever recorded . This week, the overall hospitalization rate was 9.1 per 100,000 population, up from 30.5 per 100,000 last year.

Nevertheless, these lower rates do not mean that you should not receive the influenza vaccine, which has been shown to save lives, especially in children. Here's what you need to know.

When does the flu season begin?

The influenza season can begin in October in North America, but it 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, Centers for Disease Control and Prevention recommend that people 6 months of age and older be vaccinated each year. This is the first line of defense in the treatment of influenza. Although moderately or seriously ill people should wait to recover, before getting vaccinated. Only people with serious and potentially fatal 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 the vaccine or 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 anytime when approaching the fall, but October is probably the best time to do it. The CDC recommends everyone to get vaccinated by the end of October, leaving your body about two weeks to develop an immune response to the vaccine before the start of the flu season. . However, if you miss this deadline, the vaccine can 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 while lung capacity decreases. This means that if a future mother gets the flu, she is more vulnerable to life-threatening complications than the general population. Therefore, all women who are pregnant or expect to be pregnant should be vaccinated against the flu. This is all the more important since a recent CDC survey showed that only half of pregnant women receive the vaccine.

PHOTO: A woman blows herself into this undated stock image.PHOTO STOCK / Getty Images

A woman blows herself into this undated stock image.

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. So, if a person gets sick after his stroke, it's probably because his body was not yet protected from the flu, 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 off any strains of flu that might exist, 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 among people. These include fever, cough, sore throat, nasal congestion, body aches, headache, and fatigue. While the flu may seem like a cold, colds usually develop more slowly and are less likely to cause fever.

Some patients with severe infections may have symptoms – such as difficulty breathing and mental confusion – that are of concern and may require immediate medical attention to treat them. Medical attention should also be sought in children with 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 initially improve, a visit to a clinician is warranted.

A sign of flu shots is seen in a pharmacy in this undated photo.PHOTO: Getty Images / Blend Images

A sign of flu shots is seen in a pharmacy on this undated stock photo.

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 yourself with coughing and sneezing with your elbow.

People with severe symptoms, as well as people at high risk of influenza (young children, people 65 years and older and pregnant women) should contact their doctor if they develop symptoms. In some cases, people can get antiviral medications, which can reduce symptoms, shorten the duration 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, where strains of the virus are injected into eggs and incubated for several days. They are then weakened or killed and then purified for use as a spray 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 is faster in vaccine production than the older egg-based method.

Another method uses recombinant technology. In these cases, a certain gene is extracted from the influenza virus to be inserted into a different virus than the flu that develops in the insect cells. This genetically modified non-influenza virus then replicates in insect cells. Once the virus replicates, the manufacturers purify the protein produced from the influenza gene 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.

PHOTO: A person gets a vaccine in this undated stock image.Getty Images

A person receives a vaccine in this undated stock image.

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 has 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, doctors' 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 editor at the ABC News Medical Unit.