Answer based on context:

Coming off their bye week, the Colts flew to Reliant Stadium for a Week 5 AFC South duel with the Houston Texans.  In the first quarter, Indianapolis drew first blood as kicker Adam Vinatieri got a 46-yard field goal, along with RB Joseph Addai getting a 1-yard TD run.  In the second quarter, the Texans responded with RB Steve Slaton getting a 1-yard TD run, kicker Kris Brown getting a 37-yard field goal, and QB Sage Rosenfels completing a 5-yard TD pass to WR Andre Johnson. In the third quarter, Houston increased its lead with Brown nailing a 43-yard field goal. In the fourth quarter, the Texans continued its run as Slaton got a 1-yard TD run.  The Colts rallied with QB Peyton Manning completing a 7-yard TD pass to rookie TE Tom Santi, LB Gary Brackett returning a fumble 68&#160;yards for a touchdown, and Manning completing a 5-yard TD pass to WR Reggie Wayne.

How many 1-yard touchdown runs were there?
3