Vettel won four straight titles between 2010 and 2013 with Red Bull and once had a 42 point deficit on Fernando Alonso with nine races left of the 2012 season.
This year it looks a bit more difficult for the German, he is 40 points behind with just six races left, and unlike in 2012, his car is not way out in front as the fastest car in the field.
However, despite the odds being stacked against Vettel, Horner believes he has the mentality and ability to pull it back once again and win his fifth world title.
“Usually he’s very good under pressure,” said Horner. “He certainly won’t give up, he was 40-odd points before down I think in 2012.
“But obviously it will be disappointing for him to have lost out to Lewis at this race.
“The Ferrari’s a very quick car. There’s still six races to go, 150 points available.
“Anything can still happen but Lewis is over a weekend and third place ahead.”
The 44-year old has admitted that Hamilton is in the driving seat, especially considering his recent form, which has seen his finish first four times and second twice in the last six races.
Horner continued: “Obviously it looks like Lewis is in the driving seat now.
“He’s just got to be consistent to year-end. It’s going to be an uphill battle [for Ferrari] to get themselves back into it.”