CVS Caremark, part of the CVS pharmacy and health care company, sent out nearly 4,000 mailings to clients in Ohio in which information visible in the envelope’s window referenced HIV, reports The Washington Blade. CVS has since halted the mailings.

Recipients were participants in Ohio’s AIDS Drug Assistance Program (ADAP), the federal program that helps low-income people access HIV care and treatment.

Coded notations such as “PM 6402 HIV” were printed directly above the clients’ names and addresses.

“The reference code was intended to refer to the name of the program and not to the recipient’s health status,” Michael J. DeAngelis, a CVS Health spokesperson told The Blade. “No other protected health information was exposed. As soon as we learned of this incident, we immediately halted the mailings and are currently taking steps to eliminate the reference to the plan name in any future mailings.”

He added that “CVS Health places the highest priority on protecting the privacy of our patients, and we take our responsibility to safeguard confidential patient information very seriously.” (CVS Caremark is the pharmacy benefits manager for the umbrella CVS company.)

The incident comes just a few weeks after Aetna Health sent out nearly 12,000 mailings across multiple states with HIV-related information clearly visible in the envelope window. Recipients of those mailings included HIV-negative clients taking the prevention pill Truvada as pre-exposure prophylaxis (PrEP). That security breach resulted in a class-action lawsuit, which you can read about here.

According to the Blade, those in Ohio who received the CVS Caremark mailing should contact their ADAP coordinator.