The Big Bad Flu Data — What You Need to Know About Vaccine Effectiveness and Alternatives March 13, 2018
Story at-a-glance
Interim estimates from the CDC suggest the overall adjusted vaccine effectiveness against influenza for the 2017/2018 seasonal flu vaccines is 36 percent
While health officials claim flu vaccination will lessen your symptoms should you contract type A or B influenza, French research shows vaccination resulted in insignificant lessening of symptoms — limited to a reduction in initial headache complaints among those who had been vaccinated
A 2014 meta-analysis concluded the number needed to treat (NNT) for the influenza vaccine is 71. This means 71 people have to be vaccinated in order for a single case of influenza to be avoided
A 2017 meta-review found the NNT for vitamin D is 33, meaning one person is spared from acute respiratory infection for every 33 people taking a vitamin D supplement. For people with severe vitamin D deficiency, the NNT is 4
The flu shot may actually make you more susceptible to influenza and other infections — a result linked to heterologous immunity which, while lowering your risk for infection from the vaccine-included virus, also raises your risk of infection from other viral subtypes
