When it comes to immunization rates in the United States, the story is a mixed one. Among children, we’ve absolutely excelled. In fact, the Centers for Disease Control and Prevention considers the nation’s childhood vaccination rate as one of the greatest public health achievements of the 20^th century. But when it comes to American adults — 50,000 of whom die every year from vaccine-preventable diseases — it’s a very different story.

Earlier this year, CDC’s Morbidity and Mortality Weekly Report reported that uptake of recommended adult immunizations remains low and is far below Healthy People 2020 targets. (Healthy People 2020 sets the nation’s health objectives for the current decade.) In analyzing data from the 2013 National Health Interview Survey, researchers found that just more than 17 percent of adults received a tetanus-diphtheria-pertussis (Tdap) vaccine; 24.2 percent received a vaccine against shingles; just 5.9 percent of young men received a human papillomavirus vaccine; and about 21 percent of adults at high risk received a pneumococcal vaccine. During the 2014-2015 influenza season, adult flu immunization rates did go up by 1.4 percent, but the overall rate was still below 50 percent.

The low rates not only mean many adults remain susceptible to preventable diseases, but that they risk transmitting often dangerous diseases to particularly vulnerable populations, such as very young children, the elderly and those with impaired immune systems. And consider this: The flu alone costs the U.S. billions of dollars in medical care and lost productivity.

These less-than-ideal adult vaccination rates have attracted the attention and action of health professionals for quite some time. However, in September at a briefing in the U.S. Capitol in Washington, D.C., a new coalition of stakeholders from across the health care system officially declared its intention to take up the issue of adult immunizations in earnest and facilitate new solutions to strengthen and enhance access to adult vaccines. Known as the Adult Vaccine Access Coalition (AVAC), the group’s diverse members include health care providers, pharmacists, public health organizations, vaccine makers, and patient and consumer groups. Among its many member groups are the American Public Health Association, American Pharmacists Association, American Academy of Family Physicians, and the Pharmaceutical Research and Manufacturers of America.

The coalition’s policy priorities are three-fold: improving adult immunization data collection; establishing new benchmarks to measure and encourage progress; and advocating for initiatives that boost adult vaccine rates among the most vulnerable and begin to close racial and ethnic disparities in vaccine uptake. Laura Hanen, co-chair of the new coalition and chief of government affairs at the National Association of County and City Health Officials, said the coalition is an opportunity to bring all the stakeholders together and channel relevant resources and skills toward one overriding goal.

“We’ve all been working on this issue in our individual lanes, whether it’s public health groups, health care providers, pharmacists,” Hanen told me. “Now we’re coming together to create collective leverage and build more understanding and awareness around the barriers to adult immunization and try to address it in the post-Affordable Care Act era.”

So why are adult vaccine rates so low? Especially when the U.S. has made such great strides in childhood vaccination coverage. As with most public health conundrums, there are many contributors, but Hanen pointed to a few big ones. Among them are provider and patient awareness. Recommended adult vaccination schedules are not necessarily easy to understand — different vaccines are recommended for different age groups and for people with particular health issues and susceptibilities. It can be “incredibly complicated,” Hanen noted.

Cost and financial reimbursement for adult immunizations have also traditionally been barriers, she said, though new ACA provisions will likely reduce those hurdles. (Under the health reform law, adults who purchase insurance through the new insurance marketplace are entitled to Advisory Committee on Immunization Practices-recommended vaccines with no cost-sharing.) Hanen also added that geographic challenges play a role, noting that not all providers carry the full spectrum of recommended adult vaccines.

Another big contributor, she told me, is that unlike childhood vaccines, there’s no nationwide infrastructure and support system in place devoted to increasing adult vaccine rates. For children, there’s the national Vaccines for Children program, which provides vaccines at no cost to children whose families may not otherwise be able to afford the life-saving drugs. There’s the Section 317 Immunization Program, a federally funded initiative that provides vaccines to uninsured and underinsured kids and adults; there’s school vaccine requirements; and there’s comprehensive reporting of child immunizations to public health agencies so officials can identify gaps and areas of need. In other words, there’s an entire system built to ensure children are protected against vaccine-preventable diseases — and that system has worked incredibly well. Sadly, that’s simply not the case with adults.

Fortunately, AVAC wants to change that. Building on current vaccine systems to improve adult rates is a priority focus for the coalition. For example, Hanen noted that while every state has an immunization registry, their focus has primarily been on engaging with pediatricians and collecting data on childhood immunization coverage. However, the same system could be used to beef up adult vaccine rates too — health departments just need the resources to engage more diverse providers in the registry process, she said. Ideally, all vaccine providers, whether physicians or pharmacists, would be able to access the registry to view an adult’s immunization record, which would give the provider a chance to offer their adult patients seasonal or newly recommended immunizations. In addition, more providers would report adult vaccine data to the registries, providing public health practitioners with the valuable data needed to inform education campaigns, identify coverage gaps and pinpoint particularly vulnerable communities.

“The challenge is that immunization registries need more resources to be more robust,” Hanen said. “With health information technology, we have the opportunity to improve reporting and access and increase cooperability with health systems and records, but we’re not quite there yet.”

Strengthening state registries is just one piece of the coalition’s goals. Overall, AVAC is dedicated to finding systemic and evidence-based answers to the adult vaccine problem. Already, the coalition is speaking out on a number of federal measures that affect adult vaccine access and offering solutions. But as with any problem that has as many contributors and stakeholders as the adult vaccine puzzle, there’s “no magic bullet,” Hanen told me.

“That’s the big challenge,” she said. “It’s all connected, but there’s not one solution.”

To learn more about AVAC and the importance of adult immunizations, visit www.adultvaccinesnow.org.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.