i don't know. >> reporter: barreÉ-sinoussi has closed her lab, but she plans to continue her advocacyk as long as she can. she says her only regret is not finding an h.i.v. vaccine. >> i encourage a new generation of scientists today to continue. >> we will try to build a government that respects the people >> sreenivasan: on the next pbs newshour weekend. and finally, the secret service agent who nancy reagan credited with saving her husband's life has died. jerry parr was the lead agent on duty during the march 1981 assassination attempt on president ronald reagan. after would-be assassin john hinckley fired toward reagan outside a washington hotel, agent parr shoved the president into a limousine. when parr realized reagan had been shot in the chest, he ordered the limo to drive to george washington hospital. parr had also served on president carter's security detail. parr later became a minister. he was 85. >> that's it for this edition of pbs newshour weekend. i'm hari sreenivasan. thanks for watching. >> pbs newshour weekend is made possible by: corporate funding is provided by