Each year flu vaccines are recommended to protect us from influenza. The United States Centers for Disease Control and Prevention (CDC) recommends that everyone over the age of 6 months be vaccinated against the flu each year. For many years there was only one flu vaccine—a traditional flu shot that included three strains of influenza virus. However, there are now multiple options for protecting yourself from the flu. Learn about the different flu vaccine options and find out which one might be right for you and your family.
Trivalent Flu Shot
The flu shot as we have known it for decades is a traditional vaccine that is grown in chicken eggs. It is made up of three strains of influenza virus (two strains of influenza A and one strain of influenza B) that researchers believe are most likely to cause illness during the following flu season.
It takes about six months to manufacture the flu vaccine, which means that strains to include have to be chosen towards the end of the previous flu season.
It is administered as an intramuscular (IM) injection in the arm or the thigh. Children under 8 years old who have never had a flu vaccine before will need two doses four weeks apart. The initial dose of flu vaccine acts as a “primer” so the body’s immune system knows what to look for. The booster (second) dose allows the immune system to create antibodies that will help fight the flu without making the child sick if exposed.
Quadrivalent Flu Shot
The quadrivalent flu vaccine is administered in the same way that the traditional trivalent flu vaccine is. The difference is that the quadrivalent vaccine contains four strains of influenza virus (two strains of influenza A and two strains of influenza B), theoretically providing better protection against the flu.
Because we don’t know exactly which strains of influenza will make people sick each year, including additional strains of the virus in the vaccine increases the chance that the dominant strain will be included in the vaccine.
Like the trivalent flu vaccine, the quadrivalent shot is given as an IM injection. All flu vaccines take about two weeks to provide immunity and become effective.
Intradermal Flu Shot
The intradermal flu shot is quite different from other flu vaccines because it is injected into the skin rather than the muscle. It uses a much smaller needle than the traditional flu shot because it only needs to penetrate the top few layers of skin rather than going all the way into the muscle.
This type of flu vaccine is approved for use in adults between the ages of 18 and 64. People who get this vaccine report less pain than with the traditional flu shot but may experience other side effects such as itching, redness, and swelling at the injection site.
The Fluzone intradermal flu vaccine is quadrivalent, so it contains four strains of influenza.
High Dose Flu Vaccine
There are actually two different high-dose flu vaccines that are available for older adults to create an enhanced response to the influenza virus. One is the high dose trivalent vaccine and the other is a trivalent flu shot made with adjuvant. The adjuvant is an ingredient that helps the body create a stronger immune response to the virus.
Both of these vaccines are trivalent, meaning they contain three strains of influenza. They are both approved for use in adults age 65 and older.
Preservative Free Flu Vaccine
Multi-dose vials of flu vaccine contain an ingredient called thimerosal as a preservative to prevent contamination since multiple doses of vaccine are drawn out of the vial.
Although there has been no danger associated with the use of thimerosal in vaccines, there are options for flu vaccines that do not contain this ingredient. Single dose flu vaccines contain no thimerosal and are “preservative free.”
Intranasal Flu Vaccine (FluMist)
Until the 2016 to 2017 flu season, the intranasal flu vaccine called FluMist was a popular choice among flu vaccines for children. It is administered as a nasal spray—a quick squirt in each nostril and you are done.
The FluMist vaccine uses inactivated live influenza virus. It was approved for use in children over the age of 2 years old who do not have asthma or a history of wheezing. It can be used in children and adults up to the age of 49.
In 2016, the Advisory Committee on Immunization Practices (ACIP) recommended that the nasal spray flu vaccine no longer be used due to concerns about its efficacy. Recommendations may change in the future, but at this time, FluMist is not recommended for use as a seasonal flu vaccine.
Jet Injected Flu Vaccine
The jet injected flu vaccine is administered using no needle at all. It is administered using a small medical device “that uses a high-pressure, narrow stream of fluid to penetrate the skin instead of a hypodermic needle,” per the CDC.
This vaccine is trivalent—containing three strains of influenza—and is approved for use in adults between the ages of 18 and 64.
Egg Free Flu Vaccines
Gone are the days that people with egg allergies have to avoid flu vaccines. Recent studies show that nearly everyone with an egg allergy can still be vaccinated with a traditional flu vaccine. The chances of an allergic reaction to a flu vaccine are no higher in people with egg allergies than they are in people without egg allergy.
However, if you have any concern about the severity of your allergy or the possibility of an allergic reaction, there are flu vaccine options that are not grown in eggs at all and contain no egg protein.
There are recombinant flu vaccines that are both trivalent and quadrivalent. These vaccines are manufactured in a different way than other flu vaccines. They are able to be produced more quickly than traditional seasonal flu vaccines, making them a good option in the case of flu pandemics. Because they are not grown in eggs, they pose no risk for those with egg allergies. The Flublok trivalent and quadrivalent flu vaccines are approved for use in people age 18 and older.
Another egg-free flu vaccine is a quadrivalent flu vaccine that uses virus grown in cell culture. It is approved for use in people age 4 and up.
On The Horizon: Flu Vaccine Patch
Although it is not available to the public yet, clinical trials have been promising for a flu vaccine patch. This self-administered flu vaccine is placed on the arm like a sticker and removed minutes later. It contains hundreds of micro-needles that dissolve upon application.
The vaccine does not need to be refrigerated or administered by a trained medical professional like current flu vaccines do. The potential for home vaccination with this type of technology is exciting for health care providers, public health officials, and researchers alike.
Future Possibilities: Universal Flu Vaccine
Current flu vaccine rates are dismally low despite the fact that health care providers and public health officials across the country and across the world recommend them. The fact that we have to get vaccinated every year and that vaccines have variable efficacy rates play a large role in those low rates.
People understandably don’t want to take the time to get a vaccine that may or may not work. We have to make an educated guess each year about which strains of the flu may make people sick the following flu season. Sometimes we get it right and sometimes we don’t.
There are multiple studies currently underway that could change the future of flu vaccines for all of us. Multiple groups of scientists are looking into how to develop flu vaccines so that they are more effective and don’t have to be given every year because they would target a part of the influenza virus that doesn’t change. Although this isn’t possible yet, it could be available in the not too distant future.
A Word From Tips For Healthy Living
Although there are multiple options, not all of them are right for everyone. Each has specific circumstances that make you, your child, or other family member eligible for it. If you’re interested in a particular vaccine option, discuss it with your healthcare provider.