Mosesdad

Hi everyone, My 11 year old pans son accidentally used my toothbrush a few days ago and as Murphy's law would state, I would develop a cold sore that same day. He has never had a cold sore. I have valtrex at home. Do you think I should give it to him? I've been giving him 1mg 2x a day. He is 110 pounds. I know kids flare with cold sores so I'm very worried. Thanks for any thoughts or advice. Moe