|Viruses gain entry into host cells via several sites such as the skin, gastrointestinal tract, and respiratory tract. Once an infection has occurred, the virus may replicate in host cells at the site of infection or they may also spread to other locations. Animal viruses typically spread throughout the body mainly by way of the bloodstream, but can also be spread via the nervous system. Viruses have several methods to counter host immune system responses. Some viruses, like HIV, destroy immune system cells. Other viruses, such as influenza viruses, experience changes in their genes leading to antigenic drift or antigenic shift. In antigenic drift, viral genes mutate altering virus surface proteins. This results in the development of a new virus strain that may not be recognized by host antibodies. Antibodies connect to specific virus antigens to identify them as 'invaders' that must be destroyed. While antigenic drift happens gradually over time, antigenetic shift occurs rapidly. In antigenetic shift, a new virus subtype is produced through the combination of genes from different viral strains. Antigenetic shifts are associated with pandemics as host populations have no immunity to the new viral strain. Journal impact factor is an index or a criteria devised by Eugene Garfield to categorize journals based on their citations. Impact factor is considered as a putative marker to indicate the journal quality. But the recent policies being adopted to improve the impact factor is becoming a topic of controversies today. This current scenario questions the reliability of impact factor. The citation index cannot be considered to determine the scientific quality of an article because the technicalities are not considering the scientific quality. Knowing or reading an article is not enough to determine their quality validating the content and approving the findings and revalidating the facts is vital in scientific research. It is highly impossible to do a scholar check in each and every article to detect fraudulent or unsubstantial citations.