Context: Coming off their last-second home loss to Chicago, the Eagles ground out a 23-16 victory on the road against a Minnesota Vikings team coached by former Andy Reid protege Brad Childress. Rookie phenom Adrian Peterson and quarterback Kelly Holcomb, who spent the offseason on the Eagles' roster, took the Vikings down the field for the game's first score - a nine-yard touchdown pass to Visanthe Shiancoe. A 50-yard reception by Greg Lewis down the field set up David Akers' first field goal, then Donovan McNabb guided the Eagles to a touchdown drive early in the second quarter, with Brian Westbrook the recipient of a short six-yard scoring pass. Westbrook carried it up the middle from the one-yard line on Philadelphia's next drive to make it 17-7. Ryan Longwell booted a 39-yard field goal for Minnesota to draw the score to 17-10 later in the second quarter. Akers and Longwell traded field goals in the third quarter to make it 20-13. A 48-yarder by Longwell in the final quarter drew the Vikings to within four points, but they would get no closer, while Akers added his third field goal to restore the seven-point lead. McNabb's 333 passing yards were his most since the Detroit game, while Reggie Brown topped 100 yards for the first time all season. Westbrook had 92 all-purpose yards and a touchdown on the ground and in the air. Trent Cole recorded two sacks.

Question: How many points were the Vikings trailing by at halftime?

Answer:
7