They wait months at the Mexican border to legally cross into the United States 2:31 (CNN) — A few hundred migrants who have been waiting in Reynosa, Mexico, for the end of the US public health order for the pandemic, known as Title 42, they were allowed to apply for asylum this week, sources on the ground told CNN. The Biden administration is on track to end Title 42 on May 23. Trump-era policy has allowed border authorities to turn away migrants at the US southern border since March 2020. The decision to lift it now, made by the Centers for Disease Control and Prevention (CDC), has many politicians and officials on both sides of the political spectrum concerned about the potential for an increase in immigrants at the border. The asylum seekers were processed through the Reynosa-Hidalgo international port of entry in south Texas, according to three sources with direct knowledge of the process. There are more than 7,000 migrants waiting in Reynosa, Mexico for Title 42 to be lifted. The processing of several hundred migrants in just a few days is a notable exception. US immigration authorities have, in the last two years, applied humanitarian exceptions to Title 42, but only in small numbers for vulnerable migrants. According to one source, about 95 families, 45 on Tuesday and 50 on Wednesday, were able to be processed by US immigration authorities. Each family consisted of two or three members, the source said. These families, the source said, are among the most vulnerable people who have been waiting in Mexico for Title 42 to be lifted, and some have waited for more than a year. The families include pregnant women with children and women with children with special needs, the source said. Potential repeal of Title 42 raises concern 4:00 More families were expected to be processed Thursday by US immigration officials, the source added. Department of Homeland Security (DHS) officials did not directly respond to CNN’s questions about asylum seekers on Thursday, but a spokesperson said in a statement: “In accordance with the CDC order, DHS continues to grant exemptions from Title 42 to particularly vulnerable people on a case-by-case basis.” Customs and Border Protection “adapts as needed to meet operational needs,” the statement continued. “There have been no changes to DHS’ enforcement of the CDC’s Title 42 Public Health Order. Title 42 remains in effect until May 23, and until then, DHS will continue to remove single adults and families who are on the southwest border. An ACLU spokesman applauded the exceptions made but pressed the administration to move forward with its plan to end the Trump-era public health order. “Humanitarian waivers for especially vulnerable asylum seekers are great, but they by no means replace the end of Title 42 entirely and the grave danger to Haitians and others,” said Lee Gelernt, the ACLU’s lead attorney in Title 42 litigation. “We hope the administration does not back down on its promise to end Title 42 by May 23.” Earlier this month, Arizona, Louisiana, and Missouri filed suit challenging the Biden administration’s decision to end Title 42. More than a dozen states, mostly Republican-led, later joined the suit. . In a Thursday filing, the states asked for court intervention, arguing that the administration had begun processing immigrants under immigration law rather than through public health authority and that the states are likely to prevail. on the merits of their claims. A judge asked the Biden administration to respond by 1 p.m. ET on Friday. CNN’s Amy Simonson and Priscilla Alvarez contributed to this report.