Question

Influenza vaccines are changed annually in the United States. Which of the following factors contribute to this fact? (check all that apply)

_____The amino acid sequence of viral proteins changes gradually

_____RNA polymerase is error prone so mutations frequently occur

_____Viruses commonly pass on resistance genes via horizontal gene transfer

Answer 1

The correct answers are option 2 - RNA polymerase is error prone to mutations frequently occur

Antigens are proteins which are made up of amino acids.. Antibody reacts with specific site of an antigen. RNA polymerase in flu virus lack proof reading activity. For this reason transcription errors are not corrected and hence the antibody binding sites are changed frequently. So earlier administered vaccines become useless as they are unable to bind this new antigenic site. So option b is the correct answer.