Protecting the public against an outbreak like the swine flu using GlaxoSmithKline‘s vaccine Arepanrix — or a similar vaccine with an AS03 adjuvant delivery system — does not increase a risk of multiple sclerosis (MS), a population study conducted in Canada reports.
The study, “Registry Cohort Study to Determine Risk for Multiple Sclerosis after Vaccination for Pandemic Influenza A(H1N1) with Arepanrix, Manitoba, Canada,” was published in the journal Emerging Infectious Diseases.
A worldwide breakout (called a pandemic) of swine flu — caused by infection with H1N1 virus — occurred in 2009. Soon afterward, researchers noticed an increase in MS incidence among residents of three Swedish counties treated with Pandemrix, a vaccine against infection by the H1N1 virus. The vaccine is composed by inactivated virus proteins combined with the adjuvant system AS03, a combination of α-tocopherol (a type of vitamin E) and squalene (a natural substance found in olive oil) in an oil-in-water emulsion.
Another Swedish study suggested the vaccine was linked to a greater risk of sensory nerve cells response damage (paraesthesias), but not multiple sclerosis.
Although alarming, these studies were not designed to specifically evaluate a potential association between the vaccine and MS risk, and their conclusions were controversial.
Because the AS03 adjuvant is a prime delivery system for such vaccines, concerns about its safety and possible connection to diseases like MS remained. The European Medicine Agency, specifically, requested a study evaluating use of the AS03-adjuvant in vaccines and MS risk.
A Canadian research team responded by looking at MS incidence among residents of Manitoba, comparing those who were vaccinated with Arepanrix, also an AS03-adjuvanted H1N1 vaccine, and those who were not. [MS rates are high in Canada due to a complex interplay of genetic and environmental factors, and particularly high in central and western provinces such as Manitoba.]
Using a database study (NCT02367222), the researchers reviewed the clinical records of hospitalization, physician utilization, vaccination, and prescriptions for the province’s entire population.
We are sorry that this post was not useful for you!
Let us improve this post!
Tell us how we can improve this post?