。
Grandfather has caught a cold.
Literal
Honorable-grandfather [topic-は] honorable-cold [obj-を] caught-[honorific-召していらっしゃいます].
お風邪を召す is the keigo expression for 'to catch a cold' — 召す (めす) is the respectful verb replacing する/着る/食べる for social superiors. いらっしゃいます is the respectful form of いる. お祖父さま uses さま instead of さん for extra deference. Triple-layer honorifics — a textbook example of maximum respect language.