You could measure smoking cessation as a person not smoking a cigarette for 1 month, or as a person who has not smoked in a year, or a 50% reduction in the number of cigarettes smoked. Clearly the operational definition of the dependent variable is an important step in the design of the study.Some other health related conceptual variables that have many operational definitions: intelligence, fitness, health, quality of life.ou could measure smoking cessation as a person not smoking a cigarette for 1 month, or as a person who has not smoked in a year, or a 50% reduction in the number of cigarettes smoked. Clearly the operational definition of the dependent variable is an important step in the design of the study.
The majority of influenza vaccines distributed in the United States contain thimerosal as a preservative. However, an increasing amount is thimerosal-free. While the multiple dose vials still have thimerosal to prevent bacterial growth, the single-dose preparations do not.The amount of influenza vaccine that is thimerosal-free is growing every year. Thimerosal contains ethyl mercury. 2  This is a different chemical compound than mercury found in the environment (methylmercury). 3  Thimerosal has been used as a preservative since the 1930s to prevent bacterial growth in vials containing multiple doses of vaccine and other medical products.
Flulaval Quadrivalent comes in a 5mL, multidose vial containing 10 doses (0.5mL each) and a 0.5mL, single-dose, prefilled syringe, while Fluarix Quadrivalent comes in a 0.5mL, single-dose, prefilled syringe. GSK expects to supply up to 40 million doses across both vaccines for the U.S. market in the 2017-18 season. GSK is committed to broad protection against influenza so one hundred percent of GSK supply is quadrivalent. Quadrivalent vaccines are designed to help protect against two main types of flu viruses, A and B, which spread between people and can cause mild to severe illness.