Yes if someone has a virus such as a cold or flu virus and you kiss that person then the virus can be passed onto you through the kissing.
If someone is sick with the flu or cold or has any other disease it's best to avoid kissing them until the virus or disease goes away.
I know there are some diseases that some people get that can be terminal and even then it would not be a good idea to kiss that person but you can if you want too.
Just be aware that if the disease they have is contagious you might get that same disease if you kiss them.