2023-2024 FLU VACCINES

In recent years, flu vaccine technology has greatly improved. Now, instead of containing vaccines against just one or two viruses, the vaccines in use provide protection against four viruses. These vaccines are thus called Quadrivalent vaccines, and give us immunity over a broader spectrum.

There are currently three flu vaccine products in clinical use each of which vaccinates us against two influenza “A” and two Influenza “B” viruses. The Centers for Disease Control and Prevention (CDC) in Atlanta has recommended and approved these products as safe and effective. Each vaccine uses a different biotechnological process to develop and manufacture the vaccine. 

The three products are:

1. FLUZONE—high dose Quadrivalent vaccine. It is made from inactivated virus and contains four times the amount of antigen as a regular flu shot.
2. FLUBLOK—recombinant Quadrivalent vaccine. It is made using recombinant DNA technology and is completely egg free. It contains three times the antigen than standard flu vaccines.
3. FLUAD—Quadrivalent adjuvant vaccine. It is made from inactivated virus and has added an “adjuvant” ingredient that helps create a stronger immune response.

Each of these is indicated for use in adults age 65 and older and are the vaccines of choice.

Other products available, but not preferable to the three vaccines above are:

1. FLUMIST—live attenuated vaccine. It is made from attenuated (weakened) live viruses and is given in a nasal spray. It is indicated for people aged 2 through 49, and should not be given to pregnant women of immunocompromised patients. 
2. FLUCELVAX—Quadrivalent vaccine. It is made from viruses grown in mammal cell cultures and is completely egg-free. It is given to people 6 months and older.
3. AFLURIA, FLUARIX, FLULAVAL—standard Quadrivalent flu vaccines. These are approved for children as young as 6 months of age and adults aged 18-64.

As mentioned elsewhere, the best time to get a flu shot is in the months of September or October. Immunity begins to wane after six months so the later you receive the shot, the more of the flu season you will be protected. Getting vaccinated too early leaves you vulnerable after six months when immunity is declining. 

References: https://www.cdc.gov/flu/prevent/different-flu-vaccines.htm