States are taking various approaches to keeping track of COVID-19 vaccine recipients in the absence of a national database.

That’s led to a variety of methods for providing residents with documentation should they lose the Centers for Disease Control and Prevention (CDC) card that’s often handed to recipients for their own records.

The CDC does not keep track of individual vaccinations, and records usually are left with patients, doctors and clinics. From there, states can decide how much or how little data they want to collect.

Oklahoma records its vaccinations through a state immunization database, allowing patients to find verification of their vaccine online if they lose or damage their vaccine cards. In Illinois, providers are required to report COVID-19 vaccinations to the state health department, and recipients can voluntarily enter their information into an online registry.

Experts say the differing methods will require coordination among various online portals to ensure individuals can prove they have been vaccinated.

“By asking states to create and manage their own IT infrastructure systems, we have essentially reinvented the wheel 50 times,” said Aparna Soni, an assistant professor in the Department of Public Administration and Policy at American University.

Soni said statewide recording systems can let health officials know which residents of theirs have been vaccinated, but those same states are unable to see how many visitors have been vaccinated.

The existing setup alo creates inequities on the tech front as well, she said.

“The current system puts the burden of developing IT infrastructure on state governments, and some states are better equipped to do this than others,” Soni said.

Things can get even more complicated depending on where someone received their vaccine.

Jeremy Youde, the dean of the College of Liberal Arts and a professor of political science at the University of Minnesota Duluth, said recording methods can vary based on whether the vaccine was administered at a pharmacy or a government-run site.

“We end up with a pretty wide array of different tracking capabilities and record keeping programs across the country,” Youde said, adding that compatibility issues could very well arise between states.

For example, he said Minnesota has been developing a comprehensive statewide database of everyone who has been vaccinated, but another state may be collecting different data points and not be satisfied with Minnesota’s methods.

Youde said travelers might face this issue when visiting another state than where they were vaccinated.

“All these questions are going to build up the less compatible these systems are,” he said.

The Federal Retail Pharmacy Program is currently allowing 21 national pharmacies to offer COVID-19 vaccines through a collaboration with federal and state governments.

Susan Hassig, an associate professor in the epidemiology department at Tulane University, said Louisiana worked to connect providers with its immunization registry program as COVID-19 vaccines began rolling out.

But she said one limitation of the system is that it does not have a census of all Louisiana residents, so it is only aware of those who have been vaccinated.

Hassig, who helped advise the state on its rollout plan, said even though the state’s system may be somewhat different from others, many are similar in their design and objective.

“The lack of uniformity and transparency in a lot of our information systems is challenging, but it reflects the fact that we've got 50 states plus the territories and they each do things their own way,” Hassig said, adding that for privacy purposes, state data is not pooled together and one state cannot see another’s information.

Privacy concerns have sparked a firestorm in the past few weeks as several governors in GOP-led states have taken action to prohibit “vaccine passports” that would allow businesses to require patrons show proof of vaccination before entering places like sporting venues or smaller establishments like indoor restaurants.

White House press secretary Jen Psaki last week said the federal government will not enforce any kind of vaccine passport system, leaving the decision up to private businesses and nonprofits.

Ben Clark, an associate professor in the School of Planning, Public Policy and Management at the University of Oregon, said that while the overall tracking of vaccinations is a “patchwork of different actors” pulling their data together, the system seems more robust than the one that tracked COVID-19 infections at the start of the pandemic.

Public health officials have had time to learn about developing dashboards for recording this type of data, Clark said, and they are more sophisticated than at this time last year.

For any future viral outbreaks, Clark said there are lessons to be learned from the coronavirus pandemic about what role the federal government should play in tracking a disease.

Clark said that as the Biden administration and Centers for Disease Control and Prevention think about preparing for the next pandemic, they should "think about the type of data infrastructure that will help in managing the pandemic, in reporting out to be much stronger."

Jonnette Oakes contributed.