As the U.S. flipped the final pages of the COVID-19 pandemic on Friday, so did the CA Notify exposure notification system for smartphones.

The California Department of Public Health's CA Notify computer program was designed to alert iPhone and Android users about potential exposure to COVID-19 during the pandemic.

The contact-tracing app officially launched in December 2020 to tell people if they have spent time near someone who tested positive for the novel coronavirus. The app used the phone's location to determine if one got exposed, according to an NBC Bay Area review.

As of Thursday, the systems powering the COVID-19 exposure notifications are no longer active. In a press release issued on the same day, the department explained that the systems were timed to shut down on the same day the country's COVID-19 State of Emergency ends.

Users who opted in for the CA Notify alerts should have received smartphone notifications, saying their device "will no longer log nearby devices and you won't be notified of possible exposures."

In the absence of the contact-tracing app, the department encouraged everyone to remain vigilant since the virus responsible for the COVID-19 pandemic is still actively spreading.

"We encourage people to continue following current CDPH COVID-19 guidance. Vaccines, at-home tests and strong treatment options continue to be successful in the fight against COVID-19," the department stated.

And though CA Notify will no longer tell public users of their exposure risk, the department assured everyone that it would continue to work with its partners in making the app to repurpose it for future responses related to COVID-19 or other diseases.

On Friday, the public health emergency declaration expired. Alongside it, the U.S. government announced it would no longer require international air travelers heading to the U.S. to show proof of COVID-19 vaccination.

"Considering the progress that we have made, and based on the latest guidance from our public health experts, I have determined that we no longer need the international air travel restrictions that I imposed in October 2021," U.S. President Joe Biden proclaimed earlier this week.

Last week, the World Health Organization (WHO) announced that the pandemic was coming to an end. However, the organization admitted that SARS-CoV-2 remains a global threat since the virus continues to mutate and spread.

A new report published in the journal Nature said the novel coronavirus is unlikely to cause big waves in the post-pandemic era. Though it does not show signs of having a seasonal pattern of spread, it can trigger less-alarming wavelets of mild infections.