An anti-illegal immigration bill amending the Immigration and Nationality Act (INA), IIRIRA covered everything from border control to penalties on immigrants and employers who violate the immigration laws to allowable benefits for immigrants. Many immigrants were affected by new three- and ten-year bars to admissibility for having been "unlawfully present" in the United States (having entered without any inspection or overstayed a nonimmigrant visa). New vaccination requirements for immigrants were also added. The Act also prevented certain immigrants -- including some with green cards -- from receiving government benefits such as Social Security. Applying for asylum also became more difficult under IIRIRA, as applicants were required to apply within a year after entering the United States and were refused work permits until their cases had been granted.