Viruses may either have DNA or RNA as their genetic material. RNA viruses, or riboviruses, employ RNA rather than DNA to carry and pass on genetic information. These viruses make copies of themselves within host cells by employing specialized enzymes such as RNA-dependent RNA polymerase or reverse transcriptase, depending on whether they adopt a positive-sense, negative-sense, or retroviral replication mechanism. Influenza, SARS-CoV-2, HIV, and poliovirus are some examples of RNA viruses.
RNA viruses have a higher mutation rate than DNA viruses because there are no proofreading mechanisms present during replication. Their high rate of mutation makes it difficult to create long-term vaccines or drugs against some RNA virus infections. Some RNA viruses, like retroviruses, have the ability to integrate their genome into the host genome, causing chronic infection. Understanding RNA viruses is important for the formation of antiviral drugs, vaccines, and successful strategies to counter emerging viral diseases.