GlaxoSmithKline (GSK) has notified the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) that it is recalling the remaining doses of its 2014-2015 Flulaval Quadrivalent Thimerosal-free Pre-Filled Syringes (PFS) flu vaccine over concerns about the vaccine’s effectiveness.
GSK voluntarily initiated this recall because of the potential that Flulaval pre-filled syringes may have diminished effectiveness due to a decrease in potency detected through routine testing, according to the CDC. The vaccine’s potency fell below a specified limit before the expiration of the vaccine. According to the drug maker, the potency issue affects only the pre-filled syringe vaccine doses administered in early January 2015 or later. Doses that were administered before the end of 2014 did not fall below the specified limits. The reduced potency of the GSK Flulaval pre-filled syringes vaccine does not pose a safety concern for anyone who received it.
Thirteen lots of vaccine are affected by the recall and include: 2B472 /379MY /42N4L / 5AZ7H / 9A3ZM / ZS95Z / A2PK7 / AR57J / DR4GF / YF5DT / F45C5 / T3J4S / XP4J2.
Flulaval Quadrivalent PFS flu vaccine is supposed to protect against four influenza (flu) viruses: two influenza A viruses and two influenza B viruses. The issue with the recalled doses is a slightly reduced potency (less than 5 percent below the minimum specification) in the two influenza B viruses contained in the 2014-2015 Flulaval pre-filled syringes. The loss of potency means that the vaccine no longer meets the manufacturer’s specifications for potency for these particular viruses. (The potency for the two influenza A viruses in the vaccine was within specified limits.) Potency (or strength) of a vaccine is determined by the measurement of the concentration of the active ingredient (also called antigen) in the vaccine, the CDC explains. Reduced potency does not necessarily mean people vaccinated with this vaccine received reduced benefit, although it is a possibility.
Because flu activity in the United States is declining at this time of year, the CDC does not recommend revaccination for people who received the recalled vaccine. But anyone who was vaccinated in early January 2015 or later and wishes to be revaccinated should speak with a doctor. Anyone who was vaccinated in early January 2015 or later, and who is planning to travel to the Southern Hemisphere, where flu season is just beginning, may wish to speak to their doctor about flu treatment or prevention options, including being re-vaccinated with another 2014-2015 flu vaccine. A new flu vaccine has been formulated for use in the Southern Hemisphere, and so vaccination with a Northern Hemisphere flu vaccine might not provide optimal protection against flu viruses expected to circulate in the Southern Hemisphere in the coming months.
GSK has sent a letter to customers who purchased Flulaval Quadrivalent PFS with directions for returning any unused vaccine from these lots.