After three years, more than 100 million cases and 1.1 million deaths, the COVID-19 public health emergency in the United States is coming to an end after Thursday.

The formal end of the public health emergency, first put in place on Jan. 31, 2020, by then-Health and Human Services Secretary Alex Azar, comes one week after the World Health Organization declared that the coronavirus is no longer a global health emergency, a key step forward in shifting the response to the deadly virus.

The Biden administration this week touted the success of its progress against fighting the virus – including over 270 million people getting at least one COVID-19 shot and more than 750 million free COVID-19 tests being distributed – while detailing how some programs offered by the federal government will shift after Thursday.

Here’s a look at what will change after Thursday:

Much of the changes related to COVID-19 tests, treatments and preventative measures will depend on what kind of insurance you have. But one thing that will not change for several months is access to COVID-19 vaccines.

COVID-19 vaccines will still be free while the supply lasts, thanks to the federal government purchasing supplies.

Vaccines will be covered by private insurance, part of the Affordable Care Act, as well as for those on Medicare, Medicaid and the Children's Health Insurance Program (CHIP).

For those without insurance, the Department of Health and Human Services launched a program last month – the HHS Bridge Access Program for COVID-19 Vaccines and Treatments – which is a public-private partnership that will provide access to vaccines and treatments through December 2024.

Once the emergency ends, private insurers will no longer be mandated to reimburse for testing, according to an analysis from the Kaiser Family Foundation, though they may cover tests ordered by a medical provider.

Per the KFF's analysis, the median price of a COVID-19 test in an outpatient clinical setting was $45 in 2021 among those who had large employer-based health plans. That figure varies in different parts of the country and does not include other costs associated with a doctor's office or hospital visit.

At-home tests will no longer be free under traditional Medicare and Medicare Advantage plans; for those on the former, there will be no cost for lab tests ordered by a provider. For those on Medicaid and CHIP, there will be coverage for tests through September 2024.

When it comes to treatments, the cost will vary. The federal government still has supplies of antiviral treatments such as Paxlovid, and those will be available at no cost until supplies run out. And for those without insurance, access to certain treatments will be free under the HHS Bridge program until December 2024.

One of the most closely watched events set to take place with the end of the COVID-19 public health emergency is the end of Title 42, the pandemic-era restriction that allows the U.S. to turn away migrants and asylum seekers.

The impending lifting of the order has led to fears that the border may soon be overwhelmed with migrants seeking entry to the U.S.

In the lead-up to the expiration of the rule, Title 42, the Biden administration is looking to alleviate concerns about the policy change.

"The lifting of the Title 42 public health order does not mean our border is open," Department of Homeland Security Secretary Alejandro Mayorkas said. "In fact, it is the contrary" with "tougher consequences for people who cross the border illegally."

“When the Title 42 order lifts at 11:59 p.m. Thursday, the United States will return to using Title 8 immigration authorities to expeditiously process and remove individuals who arrive at the U.S. border unlawfully," DHS said in an April fact sheet. 

State Department officials on Tuesday offered more details on the federal government’s planned response to lift Title 42 and return to Title 8, the section of federal law that enumerates the rules for processing migrants, including those for deportation. Title 8 was the rule in place until the Trump administration installed Title 42 in an effort to quickly expel migrants.

Officials said that, just as much as the government seeks to offer legal entry for migrants, it also seeks to punish illegal attempts at entering the country.

Officials also noted that the Biden administration will implement “a comprehensive, multi-agency, multi-country plan rooted in enforcement, deterrence and diplomacy to humanely manage the border.” That includes up to 1,000 asylum officers to handle interviews along the border, 24,000 law enforcement officers deployed to the border and 1,100 new border patrol processing coordinators.

"We are finalizing a new rule to encourage individuals to use available lawful, safe and orderly pathways to enter the United States," Mayorkas said Wednesday. "The rule presumes that those who do not use lawful pathways to enter the United States are ineligible for asylum. It allows the United States ... to remove individuals who do not establish a reasonable fear of persecution in the country of removal. Noncitizens can rebut this presumption only in very limited circumstances."

He also said the U.S. is launching a digital advertising campaign in Central and South America to "counter the lies of smugglers with accurate informaton about U.S. immigration laws."

Law enforcement has arrested nearly 10,000 smugglers during the Biden administration, according to Mayorkas, and the U.S. is working with Colombia and Panama to stop smugglers before they reach the border.

The White House announced earlier this month the end of vaccination requirements for federal employees, federal contractors and international air travelers after Thursday. The travel restriction will also apply to non-U.S. travelers entering the country via ferries and land points of entry.

“While vaccination remains one of the most important tools in advancing the health and safety of employees and promoting the efficiency of workplaces, we are now in a different phase of our response when these measures are no longer necessary,” the White House said in a release at the time.

The vaccine mandates for federal contractors and employees faced numerous legal challenges.

Spectrum News' David Mendez and Joseph Konig contributed to this report.