Vaccines are made to prevent the common diseases from harming the body, but those who remain unvaccinated pose a threat to themselves, others and even the economy. The University of North Carolina estimates those who go unvaccinated cost the U.S. $7.1 billion in 2015.

The study, from the UNC Eshelman School of Pharmacy in Chapel Hill, North Carolina, set out to find the actual cost of both in- and outpatient care and medication along with the value of time lost.

Led by associate professor Sachiko Ozawa, the team evaluated the 10 most common vaccinations (for hepatitis A, hepatitis B, herpes zoster virus, human papillomavirus, influenza, measles, mumps, rubella, meningococcal disease, pneumococcal disease, tetanus, diphtheria, pertussis and chickenpox).

Results found:

• The flu tops the list with costs and lost productivity amounting to $5.8 billion.
• Pneumococcal diseases amounted to $1.9 billion in costs.
• Herpes zoster that causes shingles amounted to $782 million in costs.
• Overall unvaccinated cost of treating disease capable of being vaccinated against was $9 billion.
• Cost of inpatient and outpatient case accounted for 95 percent of costs.
• Lost productivity accounted for the remaining 5 percent.

"We believe our estimates are conservative and highlight the potential economic benefit of increasing adult immunization coverage and the value of vaccines," said Ozawa. "We hope our study will spur creative health care policies that minimize the negative spillover effects from people choosing not to be vaccinated while still respecting patients' right to make informed choices."