Under the interim arrangement, Mr Zahawi will serve as a joint minister between the health department and the business department, where he currently works.
His primary focus will be on delivering the vaccine, with most areas of his business portfolio put aside.
It comes as a further 479 deaths within 28 days of a positive test were reported in the UK, bringing the total to 58,030. There were also a further 15,871 positive cases registered in the past 24 hours.
In a tweet, Mr Zahawi welcomed his new post but said the rollout would be a “big responsibility and a big operational challenge”.
He added that he was “absolutely committed to making sure we can roll out vaccines quickly – saving lives and livelihoods and helping us #buildbackbetter”.