Question: Neutralising antibodies that recognise influenza-A virus are usually directed against the haemagglutinin or the neuraminidase. Antibodies against the M-protein do not usually protect against infection. Identify two possible explanations for these observations. Note that some of the statements may be true, but do not explain the observation. The marking scheme on this question awards marks for the two best explanations and penalises random selections or answers that cannot explain the observation. Need Assignment Help?
Question Select one or more: a. The haemagglutinin and neuraminidase often vary between different strains of influenza-A.. b. Antibodies that recognise surface components of the virus can prevent it from attaching to cells, and thus prevent infection. c. The M-protein varies greatly between strains of the virus, so neutralising antibodies do not recognise this antigen. d. Peptides of the haemagglutinin are recognised by TH2 cells, which help the B cells to make antibody. e. B cells recognise intact antigens (eg the haemagglutinin), but not antigenic polypeptides (eg the M-protein). f. The haemagglutinin is present on the surface of infected cells as well as the viral envelope. g. The M-protein is an internal component of the virus and not normally accessible to antibodies. h. The M-protein is not antigenic, so it induces only a weak antibody response.