Disabling iMessage Reactions iOS 10+
You can disable or "reduce" motion throughout iOS. Disadvantage: Not only iMessage will deactivate special effects, but Apps will also open in a "not so flashy" way.

To try it out:


  
  Open Settings.
  Tap on General.
  Tap on Accessibility.
  Tap on Reduce Motion.
  Tap the switch on the right side of Reduce Motion to turn it on and disable iMessage effects in the Messages app on your iPhone, iPad, or
  iPod.