Intestinal immunity is a determinant of clearance of poliovirus after oral vaccination

Peter F. Wright, Wendy Wieland-Alter, Natalia A. Ilyushina, et al.

 J Infect Dis. (2014) 209 (10): 1628-1634.

Speaker: Andy D. Y. Hu (胡敦堯)                                 Time: 13:00~14:00, Jun. 11, 2014

Commentator: Dr. Chiou-Feng Lin (林秋烽 博士)             Place: Room 5761

Abstract:

    There are two ways to obtain immunity to polio；by preventing clinical poliomyelitis through serum antibody neutralization of virus and by limiting the replication of virus hence decreasing person-to-person spread. Two available polio vaccines, oral polio vaccine (OPV) and inactivated polio vaccine (IPV) are used in clinical treatment. Both vaccines can prevent poliomyelitis by inducing serum antibody, and studies suggested that OPV induces greater intestinal immunity than IPV [1]. Since measurements of intestinal antibody responses are difficult, developing an assay that can detect poliovirus-specific antibody activity is necessary.  In this study, by using stool samples obtained from a poliovirus vaccine trial conducted in Oman [2], the authors developed a neutralization assay. The results showed that neutralization activity correlated with detection of polio-specific IgA in stool suspensions collected 7 days after OPV challenge. Both neutralization and IgA in stool were associated with cessation of virus shedding by day 7. Either adaption to the host environment or early immune response resulted in viral genetic changes that led to higher amount of virus shed among strains. In summary, the data indicated that polio-specific IgA is a determinant of mucosal shedding and function through neutralization of virus. Taken together, these results provide an opportunity to understand more about the duration of mucosal immunity response to polio vaccination.

 Reference

1.     Onorato IM, Modlin JF, McBean AM, Thoms ML, Losonsky GA, Bernier RH. Mucosal immunity induced by enhance-potency inactivated and oral polio vaccines. J Infect Dis 1991; 163:1–6.

2.     Mohammed AJ, AlAwaidy S, Bawikar S, et al. Fractional doses of inactivated poliovirus vaccine in Oman. N Engl Med 2010; 362:2351–9.