Multi-dose flu shot has only 25 mcg of mercury - most commercial fish contain 23 mcg of mercury per 8 ounces of fish http://buff.ly/11CTRPw
Are multi-dose vials less expensive?
Economics are a bit complicated due to wastage with multiple vials:
Single versus multi-dose vaccine vials: an economic computational model
Most of the Western world, apart from the US, has moved on to single vials:
Whenever possible, CDC recommends that single-use vials be used and that multi-dose vials of medication be assigned to a single patient to reduce the risk of disease transmission (http://www.cdc.gov/injectionsafety/patients/syringeReuse_faqs.html).
Where to get a thimerosal/mercury-free flu shot?
Many local Costco stores carry only single vials and the cost is $14.99 if no insurance is used. The availability of additional options may improve immunization rates.
Search for a Costco pharmacy near you here, and call them to verify availability: Warehouse Locations - Costco: www.costco.com/warehouse/locator.aspx
Personal Flu Stories - CDC:
Each year in the US, nearly 20,000 children under age 5 are hospitalized due to flu-related complications. CDC recommends that children aged six months through 18 years old get a flu vaccination. Moving personal stories help parents and caregivers learn about the dangers of influenza to children and the benefits of vaccination.
Image source: Influenza virus, Wikipedia, public domain.