Key result
Mucosal gut-homing α4β7+ IgA- and/or IgG-ASC responses to poliovirus type 3 were significantly lower in subjects excreting virus following bOPV challenge compared to non-excreters (20.6% vs 37.8%, p=0.021).
Why the study?
Do circulating poliovirus-specific ASCs predict mucosal immunity to poliovirus in children previously immunized with OPV?
Cohort (n=199)
Yes
Do circulating poliovirus-specific ASCs predict mucosal immunity to poliovirus in children previously immunized with OPV?
Absolute Event Rate: 20.6% vs 37.8%
p-value: p=0.021
Virus-specific blood ASCs, especially for type 3 poliovirus, can serve as a surrogate of mucosal immunity after vaccination, potentially replacing resource-intensive stool excretion testing.
Supports ASC responses as surrogate for type 3 mucosal immunity post-OPV; extends RCT evidence for noninvasive monitoring over stool testing.
BACKGROUND: The "gold standard" for assessing mucosal immunity after vaccination with poliovirus vaccines consists in measuring virus excretion in stool after challenge with oral poliovirus vaccine (OPV). This testing is time and resource intensive, and development of alternative methods is a priority for accelerating polio eradication. We therefore evaluated circulating antibody-secreting cells (ASCs) as a potential means to evaluate mucosal immunity to poliovirus vaccine. METHODS: 199 subjects, aged 10 years, and previously immunized repeatedly with OPV, were selected. Subjects were assigned to receive either a booster dose of inactivated poliovirus vaccine (IPV), bivalent OPV (bOPV), or no vaccine. Using a micro-modified whole blood-based ELISPOT assay designed for field setting, circulating poliovirus type-specific IgA- and IgG-ASCs, including gut homing α4β7+ ASCs, were enumerated on days 0 and 7 after booster immunization. In addition, serum samples collected on days 0, 28 and 56 were tested for neutralizing antibody titers against poliovirus types 1, 2, and 3. Stool specimens were collected on day 28 (day of bOPV challenge), and on days 31, 35 and 42 and processed for poliovirus isolation. RESULTS: An IPV dose elicited blood IgA- and IgG-ASC responses in 84.8 to 94.9% of subjects, respectively. In comparison, a bOPV dose evoked corresponding blood ASC responses in 20.0 to 48.6% of subjects. A significant association was found between IgA- and IgG-ASC responses and serum neutralizing antibody titers for poliovirus type 1, 2, 3 (p<0.001). In the IPV group, α4β7+ ASCs accounted for a substantial proportion of IgA-ASCs and the proportion of subjects with a positive α4β7+ IgA-ASC response to poliovirus types 1, 2 and 3 was 62.7%, 89.8% and 45.8%, respectively. A significant association was observed between virus excretion and α4β7+ IgA- and/or IgG-ASC responses to poliovirus type 3 among immunized children; however, only a weak association was found for type 1 poliovirus. DISCUSSION: Our results suggest that virus-specific blood ASCs, especially for type 3 poliovirus, can serve as surrogate of mucosal immunity after vaccination. Further studies are needed to evaluate the duration of such memory responses and to assess the programmatic utility of this whole blood-based mucosal ASC testing for the polio eradication program.
No takes yet. Share an insight, caveat, or question.
Dey et al. (2016) conducted a cohort in Poliovirus immunity (n=199). Poliovirus excretion following bOPV challenge vs. No poliovirus excretion was evaluated on Mucosal gut-homing (α4β7+) IgA- and/or IgG-ASC response to poliovirus type 3 (p=0.021). Mucosal gut-homing α4β7+ IgA- and/or IgG-ASC responses to poliovirus type 3 were significantly lower in subjects excreting virus following bOPV challenge compared to non-excreters (20.6% vs 37.8%, p=0.021).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: