There is every chance the role could turn into that of stand-in captain, with Lanning no guarantee to return from personal leave before a December T20 series in India.
Australia also have a home series against Pakistan in January, before a Twenty20 World Cup in South Africa in February.
Lanning took indefinite leave following Australia's Commonwealth Games success in August, and is believed to be overseas while confirming she would not play in this summer's WBBL.
Healy has long been considered a front-runner for the role, having led NSW at state level for the past four years and filled in as Australia vice-captain last summer.
"It's a privilege to have been offered the vice-captaincy of any Australian team, let alone one that's tasted as much success as this one," Healy said. "Rach played a key role in supporting Meg as well as driving the values and culture of the team and while she leaves big shoes to fill, I'm looking forward to helping lead this side alongside Meg and Shell.
"It's a really exciting time to be involved with this team; we've seen personnel changes as well as the emergence of incredible young talent, and with a T20 World Cup and away Ashes just around the corner, I'm looking forward to this next chapter of my career."
Healy's appointment comes as Australia faces a changing of the guard in coming seasons.
The 32-year-old has spoken publicly on how she too has considered her future in recent months, while Ellyse Perry is another superstar aged over 30.
Shelly Nitschke was last month named the team's new full-time coach, after previously serving in an interim capacity following Matthew Mott's exit.
CA also confirmed on Thursday that Dan Marsh and Scott Prestwidge would be her new assistants, with Ben Sawyer having also left to take on New Zealand's women's team.
"We're delighted that Alyssa has agreed to take on the role of vice-captain and look forward to the contribution she can make in tandem with Meg," chief selector Shawn Flegler said. "Alyssa is an outstanding leader on and off the field and brings a wealth of experience to the role.
"We have great confidence in Alyssa, Meg and Shelley leading the team during an exciting 12-month period that will see the team defend its T20 World Cup title and look to retain the Ashes on English soil."