How to Predict the Immune Status of Poliovirus Vaccinees? A Comparison of Virus Neutralization at a Very Low Serum Dilution versus ELISA in a Cohort of Infants

Abstract

A cohort of children from Gaza was observed from birth to the age of one year. Blood specimens were collected at birth, before and after poliovirus vaccination and at one year of age. Poliovirus immunity before and after vaccination was assessed by ELISA and virus neutralization (NT). Positive predictive values for ELISA were between 81.5% and 90.8%. However, ELISA revealed a high frequency of false negatives, and unacceptably low negative predictive values between 28.6% and 55.4%. The history of poliovirus immunity in the cohort was further investigated by NT. A high level of seropositivity to poliovirus type 1 (PV-1) was found. In cord blood, 83.3% had a NT titre greater than or equal to 4 and 99.0% had a titre greater than or equal to 2. Similarly, by one year of age, 85.7% had a titre greater than or equal to 4 and 90.5% had a titre greater than or equal to 2. Seropositivity to PV-2 and PV-3 were slightly lower, ie 80.8% of children had a PV-2 titre greater than or equal to 4 and 75.4% had a PV-3 titre greater than or equal to 4. As for other developing areas, poliomyelitis eradication in Gaza will come about when universal vaccination fills all 'immunity gaps' and improved sanitation and housing reduces the endemicity of wild polioviruses.

Inducing Dose Sparing with Inactivated Polio Virus Formulated in Adjuvant CAF01

“…The increased antibody response induced by CAF01 also correlated with an increased cellular response measured by multiplex cytokine analysis. Although the cellular immune response is not considered a direct correlate of protection for polio vaccines it may play an indirect role by supporting a memory B cell response [56,57]. Our analysis of anti-IPV T cell immunity revealed that CAF01 induced both a faster and stronger response against IPV.…”

Serum and mucosal antibody responses to inactivated polio vaccine after sublingual immunization using a thermoresponsive gel delivery system

“…28,42,50,51 Neutralizing antibody titer generally has been accepted as the correlate of protection for poliovirus vaccines and is used as the gold standard to determine effectiveness of poliovirus vaccination. 52,53 However, mucosal IgA responses have also been reported to be important for control of poliovirus infection. 41,54,55 Salivary and fecal IgA are considered to represent the common mucosal immune response (secretory IgA) that can prevent initial pathogen entry, while circulating IgA and IgG form a second line of defense, mediating elimination of pathogens that have breached the mucosal surface.…”

Aluminium hydroxide potentiates a protective Th1 biased immune response against polio virus that allows for dose sparing in mice and rats

“…Although the cellular immune response is not considered a direct correlate of protection for polio vaccines it may play an indirect role by supporting a memory B cell response [35,36]. Our analysis of anti-IPV T cell immunity revealed that aluminium hydroxide induced both a faster and stronger response against IPV.…”