For years, California and other states have collected detailed personal data from those getting immunizations to ensure children received the required shots.
With the rollout of coronavirus vaccines, experts say the collection of names, addresses, birth dates and other information will be vital to tracking the safety and effectiveness of products that were developed in record time.
But there are concerns that the plan to collect such data could stop some of those most vulnerable to the coronavirus, including essential workers who are in the country illegally, from lining up for vaccination.