Flu Vaccine Softens the Blow

Innoculation can help prevent decline and disability

FLU CAN set off a domino effect of decline and disability, the National Foundation for Infectious Disease warns. Early estimates from the Centers for Disease Control indicate that over 900,000 people were hospitalized and more than 80,000 died during the last flu season. The CDC calls the estimates “record-breaking.”

Several studies show that flu vaccination reduces the risk of serious illness and outcomes. A 2017 study by the CDC was the first of its kind to find that vaccination reduced the risk of flu-associated death by 51% among children with underlying high-risk medical conditions and by 65% among healthy children. An August 2018 study by CDC found that vaccination lessened the risk of severe flu among adults, including hospitalization.

A few things are new this season. Among them:

• Vaccines that better match circulating viruses.
• The nasal spray flu vaccine (live attenuated influenza vaccine or “LAIV”) is recommended for people in whom it is appropriate and approved for non-pregnant individuals, ages 2 to 49. There is a precaution against the use of LAIV in people with certain underlying medical conditions. All LAIV is quadrivalent.
• Most regular-dose egg-based flu shots are quadrivalent.
• All recombinant vaccine is quadrivalent.
• Cell-grown flu vaccine is quadrivalent. Influenza A(H3N2) and both influenza B reference viruses are cell-derived; influenza A(H1N1) is egg-derived. The reference viruses are grown in cells to produce the components of Flucelvax.
• No intradermal flu vaccine is available.
• The age recommendation for “Fluarix Quadrivalent” is now age 6 months and older.
• The age recommendation for Afluria Quadrivalent is now age 5 and older.

Recommended Flu Vaccines
For the 2018-2019 flu season, options include:

• Standard dose flu shots. While usually given with a needle into the muscle, two (Afluria and Afluria Quadrivalent) can be given to some people (ages 18-64 years) with a jet injector.
• High-dose shots for older people.
• Shots made with adjuvant for older people.
• Shots made with virus grown in cell cultureShots made using a vaccine production technology (recombinant vaccine) that does not require the use of flu virus.
• LAIV for persons in whom it is appropriate.

What viruses will the 2018-2019 flu vaccines protect against? Trivalent vaccines are recommended to contain:

• A/Michigan/45/2015 (H1N1)pdm09-like virus
• A/Singapore/INFIMH-16-0019/2016 A(H3N2)- like virus (updated) • B/Colorado/06/2017-like (Victoria lineage) virus (updated)

Quadrivalent vaccines, which protect against a second lineage of B viruses, contain the three recommended viruses above, plus B/ Phuket/3073/2013-like (Yamagata lineage) virus.

Children who need two doses should start sooner, because doses must be given at least four weeks apart. Recommendations for people with egg allergies are the same as last season.

While the use of cell-grown reference viruses and cell-based technology may potentially offer better protection over traditional, egg-based flu vaccines because they result in vaccine viruses more similar to flu viruses in circulation, there are no data yet to support this. There is no preferential recommendation for one injectable flu vaccine over another.