Medical studies with new or exciting information always make the top headlines, and this week was no exception. The decline in soda sales after the Philadelphia soda tax, the link to traumatic brain injuries and dementia and an unauthorized herpes vaccine investigation were at the top of reader’s minds this week.

Let’s take a look.

FDA launches an investigation into a professor who gave an unauthorized herpes vaccine.

The FDA is investigating William Halford, a Southern Illinois University for administering his experimental vaccine to patients without safety oversight from the organization or an institutional review board. Read the full story on U.S. News here.

A new Senate bill is trying to make it easier for hearing aid patients to get the assistance they need.

Many patients who can afford hearing aids still have trouble affording assistance to learn, adjust and use their new hearing aids properly. This new bill would allow payment for audiologists to teach beneficiaries how to use their new tech. Read the full report on NPR.

A study of 2.8 million patient records found a link between traumatic brain injury and a significantly higher risk of dementia

“What surprised us was that even a single mild TBI was associated with a significantly higher risk of dementia,” lead author Jesse Fann said in the press release. Read the story here.

As it turns out, taxing soda will cause more people to not buy soda, which could lead to potential health benefits

Drexel University found that Philadelphia’s new soda tax caused a 40 percent drop in daily soda consumption among residents in the two months after it took effect. Read the full report here.

On this week’s episode of “U.S. Healthcare Is Expensive”, a significant portion of Americans use their tax refunds to pay for healthcare expenses

The JPMorgan Chase Institute found a “dramatic link between health care spending and tax refunds.” Women, young people and those without savings are “more likely to defer care” until receiving a refund, according to the report. Read the full story on CNBC here.