Flu Shot Pros and Cons

How Do Immunizations Work?

Immunizations (vaccines) work by stimulating your body’s immune system to create antibodies, according to the CDC. This helps your body understand how to fight off an infection without the dangers of having a real infection. Because some viruses mutate or change over time, updated immunizations are needed to help your body’s immune system stay up-to-date.

This year, getting a flu shot, along with a COVID-19 booster and RSV vaccine (if you are eligible) are important steps in preventing another “triple-demic”, according to the CDC.

It is important to remember that even though immunizations don’t always prevent illness, they do help prevent the burden of illnesses from overwhelming hospitals and clinics across the nation.

Flu Shot Facts

The CDC recommends that everyone over the age of 6 months receive the flu vaccine on an annual basis (usually in early fall, just before flu season begins). The flu shot contains antigens for three or four of the most common flu virus strains: type A with subtype H1N1, type A with subtype h2N2, and either one or two type B virus strains.

For those who want to avoid needles, the flu vaccine is also sometimes available as a nasal spray. Regardless of the delivery mechanism, the purpose is to provide significant protection against the influenza virus and, while there are lots of mixed opinions, there is no medical evidence that indicates the vaccine causes serious harm or side effects.

Thimerosal in the Flu Shot

Thimerosal is a preservative that was used for multi-dose vials of some immunizations, to help prevent bacteria and fungi from contaminating the immunization. Some misinformation about thimerosal caused many people to worry about mercury poisoning. However, no evidence suggests that thimerosal is dangerous or causes any adverse reactions. Nowadays, you can request a thimerosal-free flu shot if you want.

Pros of Getting Your Flu Shot

Avoid severe illness and hospitalization

The CDC notes that out of 9 million influenza cases in the 2021-2022 season, there were 4 million flu-related medical visits, 100,000 flu-related hospitalizations, and 5,000 flu-related deaths. The flu shot is proven to help lower your risk of severe illness and hospitalization. In fact, the CDC notes that for every 4,000 people vaccinated against the flu, 1 death is prevented. That’s a high number when you consider that 173.37 million doses of the flu shot were distributed in the United States, last flu season alone.

Feel safer in public

People who get the flu vaccine have a better state of mind in public during the flu season, because the shot cuts a person's risk of getting the flu by between 40 and 60%. Vaccinated children are safer in schools, and vaccinated healthcare staff are safer in healthcare settings where they are frequently exposed to the virus.

High-risk patients are less likely to die of flu

People with diabetes, heart disease, or asthma are 80% less likely to die from the flu if they have had the flu vaccine. Senior citizens and children are also less likely to die from influenza if they have been vaccinated. This is why the vaccine is first offered to seniors, children, and those with special illnesses when there are vaccine shortages.

Cons of Getting a Flu Shot

Nasal vaccine could spread

Although it is highly unlikely, the nasal vaccine has transferred to other people from the recipient on rare occasions. While this is not likely, it is most likely done by fecal-oral transmission, so good handwashing techniques after going to the bathroom or changing a diaper are key for preventing this and other germs from spreading.

It is important to note that the flu shot (including the nasal flu vaccine) has not been proven to give any recipient the flu virus. Although common side effects of the flu shot can be similar to the symptoms of the flu.

You need it every year

You should get the flu shot every single year. There is no flu vaccine that is good for more than one year because the flu strains that threaten people change and evolve each year.

There are some common side effects

While the flu shot is considered safe by experts, it still has some side effects. Most people experience at least one symptom from the list of side effects. The most common ones are soreness, redness, or swelling at the point of injection. Other common side effects include sore throat, runny nose, low-grade fever, headache, or chills. While these side effects are a definite con for the flu vaccine, most people agree that they are much less severe than the flu.

Potential to develop Guillain-Barré Syndrome

The influenza vaccination is known to increase the risk of developing the Guillain-Barré Syndrome syndrome. People with this illness face symptoms like muscle weakness, changes in sensation, possible paralysis, and death in rare cases. Choosing to get the influenza vaccination is highly personal and subject to consideration of the possible risks. People should carefully weigh the pros and cons, and determine if the flu shot is a good choice in their personal situation. However, for the vast majority of people, the flu shot is a safe choice.

COVID-19 Booster Facts

So far, the CDC has recommended a booster for most people each year since the COVID-19 immunization became available. For the last two years, the COVID-19 booster has been tailored to protect against the most dominant variant, as well as the original strain of COVID-19.

We can’t predict the future, but for now, COVID-19 boosters are a part of our annual immunization recommendations from the CDC. This may change in the future, as the country moves forward with its pandemic response.

Pros of Getting a COVID-19 Booster

The pros of getting a COVID-19 booster are similar to the pros of getting your flu shot:

• Avoiding severe illness, hospitalization, and death
• Feeling safer in public situations
• Less likely to spread the virus to those who are at high risk for severe illness

The biggest of these pros is the fact that COVID-19 boosters are associated with a lowered risk of severe illness and death. In fact, studies published in The Lancet detail how COVID-19 immunizations saved tens of millions of lives globally in 2021, and continue to save lives today.

Cons of Getting a COVID-19 Booster

You may still get sick

A downside to getting the COVID-19 booster is that you could still become infected if you are exposed to someone with the virus. This is because the virus mutates quickly, so the booster is not a perfect match (however, it is still effective in preventing severe symptoms for most people).

You may have side effects from the immunization

Another con is that you may experience some side effects after getting your booster. The COVID-19 booster has similar side effects as other immunizations, including:

• Redness and soreness at the injection site
• Body aches or muscle soreness
• Fatigue
• Headaches
• Fever (in some cases)

RSV Vaccine Facts

RSV is a respiratory virus that can be particularly bad for the elderly and young children. In fact, RSV is the leading cause of hospitalization among infants in the United States, according to the New England Journal of Medicine. During the 2022 flu season, RSV surged alongside influenza and COVID-19 to cause what many called a “triple-demic” of respiratory viruses. This year, newly approved vaccines are being recommended for certain groups of people who are the most vulnerable.

Who Should Get the New RSV Immunization?

There are new RSV immunizations that are now FDA-approved and recommended by the CDC for certain people—these include:

• Adults over the age of 60
• Infants younger than 8 months who are going into their first RSV season
• Children between 8 and 19 months who were born prematurely or have heart or lung conditions
• Women who are between 32 and 36 weeks pregnant

Pros of Getting the RSV Vaccine

Lowered risk of severe illness

A major pro of the RSV vaccine is that it lowers your risk of illness. The CDC notes that the newly-approved RSV vaccine for older adults showed an 80% efficacy rate in human clinical trials. Similar to the flu shot and COVID-19 booster, the RSV vaccine is also linked to a lowered risk of severe illness, hospitalization, and death.

Passive immunity to unborn infants

For pregnant mothers, the RSV vaccine gives them a chance to pass on protective antibodies through the placenta during the last couple of months of pregnancy (this is known as “passive immunity”).

Cons of Getting the RSV Vaccine

Side effects from the vaccine

As with any immunization, the RSV vaccine has severe common side effects—including redness at the injection site, body aches, fatigue, fever, and headache. These side effects are usually mild and resolve within a day or two, according to the CDC.

Severe reaction

In some rare cases, a severe reaction can occur. Severe reactions include neurologic conditions (including Guillain-Barre Syndrome), and allergic reactions. The CDC notes that severe reactions and allergic reactions are exceedingly rare. The benefits of the RSV vaccine usually outweigh the risks for most people.

A Final Note About Vaccines

Vaccines are one of the most important and effective tools we have to prevent the spread of infectious diseases. While some people may be hesitant about getting vaccinated, it's important to understand that vaccines are rigorously tested and monitored for safety. The benefits of vaccination far outweigh the risks for most people, and the overwhelming majority of people who receive vaccines experience only a few, mild side effects, according to the CDC. In fact, vaccines have been instrumental in eradicating diseases like smallpox and drastically reducing the incidence of others like polio and measles.

By getting vaccinated, we not only protect ourselves but also those around us who may be more vulnerable to serious illness (like the elderly, young children, and those who have chronic health conditions). You can read more about vaccine safety surveillance programs like V-safe on the CDC website and historyofvaccines.org.