Cape Town - Formula 1's Strategy Group has voted not to introduce Halo in 2017, but it is still on the table for the following season.
Despite Sebastian Vettel revealing that "90 to 95%" of the drivers are in favour of the device, F1's Strategy Group voted no when it met on Thursday.
The Strategy Group comprises six teams; Mercedes, Ferrari, McLaren, Red Bull, Williams and Force India; who each have a vote while the FIA and FOM, represented by Jean Todt and Bernie Ecclestone respectively, have six votes each.
Halo, though, is by no means off the table as it could be introduced in 2018 after more development and testing.
"We'll have to look into it in more detail," F1 supremo Ecclestone told BBC Sport.
"When you look at it, it was yes and no - we haven't really got a lot of positives."
Earlier today Vettel spoke out in favour of Halo, saying F1 would be "quite stupid" not to implement it.
"We don't like the looks of it but I don’t think there’s anything really that justifies death," he said.
"We've always learnt from what happened, incidents on track, and tried to improve. That will be the first time in human history that we have learned the lesson but we don't change.
"I think it's up to us to make sure it does happen otherwise I think we'd be quite stupid."