text: what effect do nitrogen base analogs have on viruses?   hi. i'm going to try to answer this the best i can.  i've never heard of nigrogen base analogs: maybe you meant nucleotide base analogs? typically (especially in hiv) the nucleotide base analogs take the place of a normal base, making the transcription of the virus 'inaccurate' with the mistake in it.  this slows down viral replication, and helps inhibit the spread of the virus.