Polio. Smallpox. Rubella. Diphtheria.

For the vast majority of Americans living today, the closest we’ve ever come into contact with those diseases is when we bring up their respective Wikipedia pages. And yet as recently as the mid-20th century, they were still quite common.

What’s changed between then and now? Simple: vaccines. One of the greatest public health achievements of the 20th century, particularly with respect to children, immunizations have virtually eradicated those conditions in the United States. With the widespread availability of safe and effective vaccines, immunizations continue to hold great promise in the 21st century. Unfortunately, current adult immunizations rates are far too low for recommended vaccines, including influenza; pneumococcal; tetanus, diphtheria, and pertussis (Tdap); shingles, human papillomavirus; and hepatitis A and B.

Low immunization rates have consequences. For example, less than half of Americans receive the flu vaccine each year. As a result, between five percent and 20 percent of Americans get the flu annually. That may seem like a small percentage at first glance, but the consequences are severe. Flu-associated deaths have ranged from 12,000 to 56,000 annually in recent years. The flu is responsible for more than $10 billion in direct medical expenses and more than $87 billion in total costs (direct and indirect) each year.

In the United States, more than 50,000 adults die from vaccine preventable diseases annually, and thousands more suffer serious health problems. Disparities are even greater among at-risk populations, including seniors and people with chronic illness.

As a co-chair of the Adult Vaccine Access Coalition—a diverse group of health care providers, vaccine innovators, pharmacies, public health organizations, patient and consumer groups—I believe that it should be as easy as possible for everyone to receive their recommended vaccines. With our nation on the verge of potentially reshaping its healthcare system, AVAC urges Congress to ensure that immunizations remain a cornerstone of prevention and insurance coverage.

How can Congress do that? By adhering to the following principles:

Recommended vaccines should continue to be covered under all public and private healthcare plans. Under the Affordable Care Act, in-network providers in Medicaid expansion states and in group and individual private health plans must provide “first dollar coverage” of vaccines routinely recommended by the Advisory Committee on Immunization Practice (ACIP), including flu shots—meaning there is no out-of-pocket cost for patients. That’s important because evidence shows that the higher a vaccine’s out-of-pocket cost, the less likely that those who need it will receive it, which is particularly significant for low-income populations. States should continue to expand access to ACIP-recommended vaccines and provide first dollar coverage for all adult vaccines to Medicaid beneficiaries.

Federal funding for immunization programs must remain stable. The Centers for Disease Control and Prevention Section 317 program provides funding to state and local health departments to purchase vaccines, implement evidence-based community interventions to increase immunization coverage among underserved and high risk populations; respond to the growing number of vaccine preventable disease outbreaks, and support surveillance and Immunization Information Systems. Over the past several years, immunization infrastructure financing has grown more complex, with roughly 50 percent of Section 317’s FY2016 funding coming from the Prevention and Public Health Fund.  A significant funding decline to the Section 317 program would be highly detrimental at a time when disease outbreaks—from mumps in Seattle to Zika in Miami—are occurring with more regularity across the country.  Adequate funding is essential to maintaining current levels of success in childhood immunization rates, as well as making necessary strides to improve access and coverage rates for adults.

Medicare providers should encourage patients to get recommended vaccines during annual wellness visits. With the aging U.S. population, the public health impact of vaccine preventable disease and their complications is expected to grow. The annual wellness visit to which all Medicare beneficiaries are currently entitled with no out-of-pocket cost is an important opportunity for providers and patients to discuss the importance of immunizations—research shows a direct connection between a physician recommended immunization and a completed vaccination, and the National Vaccine Advisory Committee encourages efforts to increase provider engagement on this subject. The Medicare annual wellness visit should continue, and providers should use it as a prime opportunity for increasing immunization rates.

As Congress considers changes to the healthcare system, policymakers, providers, and patients must work together to ensure that improving access to and utilization of adult immunizations is a top priority. Let’s do everything we can to relegate all vaccine-preventable diseases to the history books.

The op-ed was published on The Hill on March 9

Laura Hanen is chief of government affairs for the National Association of County and City Health Officials and co-chair of the Adult Vaccine Access Coalition, a group of more than 50 health care providers, vaccine makers, pharmacies, public health organizations, patient and consumer groups working to strengthen and enhance access to and utilization of adult immunizations.