  We consider the emission of charged scalar particles from a Schwarzschild
black hole. It is shown that these particles can interact with each other
through pair annihilation, and as a result, produce photons. These photons make
a correction to the spectrum of photons that are directly emitted from the
black hole. By solving field equations using the WKB approximation, the pair
annihilation rate is taken into account for the most probable case, i.e., the
first order, and therefore the correction will be of the order of $e^2$.
Considering this scenario, we show that most interactions take place near the
event horizon of the black hole, yet the number of interactions is not large
enough to make a remarkable modification in the radiation spectrum of
particles. These results refute the claims that interactions cause immense
changes in the Hawking radiation spectrum of a black hole.
