Trav­el­ers fly­ing between West Afric­an na­tions af­fected by Ebola and the United States will now be sub­ject to ad­di­tion­al screen­ings and “pro­tect­ive meas­ures” to help pre­vent the dis­ease from spread­ing in­to the U.S., the Home­land Se­cur­ity De­part­ment an­nounced Tues­day.

All pas­sen­gers fly­ing from Si­erra Le­one, Liber­ia, and Guinea in­to the U.S. will be re­quired to enter the coun­try through five ma­jor air­ports: Dulles In­ter­na­tion­al Air­port in Vir­gin­ia; John F. Kennedy In­ter­na­tion­al Air­port in New York; Ne­wark Liberty In­ter­na­tion­al Air­port; Chica­go O’Hare In­ter­na­tion­al Air­port; and Harts­field-Jack­son At­lanta In­ter­na­tion­al Air­port.

“These air­ports ac­count for about 94 per­cent of trav­el­ers fly­ing to the United States from these coun­tries,” John­son said. “At present there are no dir­ect, non­stop com­mer­cial flights from Liber­ia, Si­erra Le­one, or Guinea to any air­port in the United States.”

All five air­ports will now be re­quired to spe­cially screen pas­sen­gers whose trips ori­gin­ated in any of those three coun­tries and to sub­mit pas­sen­gers to “ad­ded pro­to­cols, in­clud­ing hav­ing their tem­per­at­ure taken,” Home­land Se­cur­ity Sec­ret­ary Jeh John­son said in a re­lease on Tues­day.

John­son stopped short of an­noun­cing a full ban on travel between the three na­tions and the United States, des­pite in­creas­ing calls from mem­bers of Con­gress to do so. The White House has said as re­cently as last week that it op­poses such a re­stric­tion. However, John­son ad­ded: “We are con­tinu­ally eval­u­at­ing wheth­er ad­di­tion­al re­stric­tions or ad­ded screen­ing and pre­cau­tion­ary meas­ures are ne­ces­sary to pro­tect the Amer­ic­an people and will act ac­cord­ingly.”

The changes an­nounced by John­son on Tues­day will take ef­fect on Wed­nes­day morn­ing.

These re­stric­tions alone aren’t likely to ser­i­ously quiet the calls from con­gres­sion­al Re­pub­lic­ans and oth­ers for more re­strict­ive meas­ures, such as in­sti­tut­ing com­plete travel bans from those coun­tries or visa bans for their cit­izens try­ing to come to the U.S.