One kind of trivalent injection is called an intradermal trivalent shot and uses a much smaller needle than the regular flu shot.
High-Dose Shots
Recommended for those 65 and older, the high-dose flu shot contains four times the antibody-producing antigen as traditional shots. Known as the Fluzone High-Dose, the vaccine is a trivalent injection that creates a stronger immune response in the elderly population, which is at greater risk of severe flu. Seniors produce 50 to 75 percent fewer antibodies than younger adults, and some studies report that those who receive the high-dose shot reduce their risks of developing flu by 25 percent compared to traditional vaccines.
Quadrivalent Flu Vaccine
In 2013, protection from a fourth virus, another B strain, was made available, which meant manufacturers did not have to choose between two different B viruses.
“For decades, we only had vaccines for two A subtypes and one B,” says Dr. Sherif Mossad, an infectious disease specialist at the Cleveland Clinic in Ohio. “Researchers would try to predict which B virus would be most prevalent in the Northern Hemisphere based on what happened in the Southern Hemisphere. For the past 10 years, [researchers] have tended to pick the wrong B, so now you can be protected against both.
“The best estimates are that adding another B subtype may prevent up to 100,000 additional infections and up to 8,000 hospital admissions.”
The quadrivalent vaccine has been approved for children as young as 6 months old. One factor that may prevent a person from choosing the quadrivalent vaccine is cost -- it tends to be more expensive. Be sure to ask your healthcare provider or insurance company the price of the quadrivalent vaccine before making your choice.