[The status of immunity against poliomyelitis. The 5th cooperative study of the German Union to Control Viral Diseases, Inc]

Is EU/EEA population protected from polio?

The WHO European Region has been declared polio-free since 2002. By 2010, inactivated polio vaccine (IPV) was the only polio vaccine in use in the EU/EEA for the primary vaccination of children. A systematic review of the literature on polio seroprevalence studies, complemented by the analysis of available vaccine coverage data, has been carried out with the aim of assessing the level of protection against polio in the European population. A total of 52 studies, with data from 14 out of the 31 EU/EEA countries, were included in the analysis. This systematic review shows that, overall, seroprevalence for PV1 and PV3 is high in most countries, although seroimmunity gaps have been detected in several birth cohorts. In particular, relatively low immunity status was found in some countries for individuals born in the 60's and 70's. Discrepancies between reported vaccination coverage and immunity levels have been also highlighted. Countries should make sure that their population is being vaccinated for polio to reduce the risk of local poliovirus transmission in case of importation. Moreover, assessing immunity status should be priority for those traveling to areas where wild polioviruses are still circulating.

Deficiency of immunity to poliovirus type 3: a lurking danger?

Background

Europe was certified to be polio-free in 2002 by the WHO. However, wild polioviruses remain endemic in India, Pakistan, Afghanistan, and Nigeria, occasionally causing polio outbreaks, as in Tajikistan in 2010. Therefore, effective surveillance measures and vaccination campaigns remain important. To determine the poliovirus immune status of a German study population, we retrospectively evaluated the seroprevalence of neutralizing antibodies (NA) to the poliovirus types 1, 2 and 3 (PV1, 2, 3) in serum samples collected from 1,632 patients admitted the University Hospital of Frankfurt am Main, Germany, in 2001, 2005 and 2010.

Methods

Testing was done by using a standardized microneutralization assay.

Results

Level of immunity to PV1 ranged between 84.2% (95%CI: 80.3-87.5), 90.4% (88.3-92.3) and 87.5% (85.4-88.8) in 2001, 2005 and 2010. For PV2, we found 90.8% (87.5-90.6), 91.3% (89.3-93.1) and 89.8% (88.7-90.9), in the same period. Seroprevalence to PV3 was 76.6% (72.2-80.6), 69.8% (66.6-72.8) and 72.9% (67.8-77.5) in 2001 and 2005 and 2010, respectively. In 2005 and 2010 significant lower levels of immunity to PV3 in comparison to PV1 and 2 were observed. Since 2001, immunity to PV3 is gradually, but not significantly decreasing.

Conclusion

Immunity to PV3 is insufficient in our cohort. Due to increasing globalization and worldwide tourism, the danger of polio-outbreaks is not averted - even not in developed countries, such as Germany. Therefore, vaccination remains necessary.

Humoral immunity against diphtheria, tetanus and poliomyelitis after antineoplastic therapy in children and adolescents--a retrospective analysis

Serum antibodies against diphtheria- and tetanus-toxin were measured in 71 children and against poliomyelitis viruses 1-3 in 65 children and adolescents 0-18 months after cessation of antineoplastic therapy. Non or marginally protective serum titers were found in 62% of patients against diphtheria, in 18% of patients against tetanus and in 72% of patients against one or more poliomyelitis virus serotypes. Of these patients, 55%, 46% and 75% were immunized adequately according to age against diphtheria, tetanus and poliomyelitis, respectively. In 50% or more of patients a lack of protective immunity against diphtheria, tetanus and poliomyelitis was found which could not be explained by an inadequate immunization status. This suggests that other factors (e.g. influence of underlying illness, antineoplastic therapy or both on lymphocytes) might be responsible for these findings and this deserves further investigation. Measurement of serum antibodies against vaccine-preventable illnesses and consecutive booster immunizations are an essential part of long-term follow up in pediatric patients after antineoplastic therapy.

Epidemiological analysis of immunity to poliovirus after termination of an era of vaccination with OPV in Germany. An analysis of the German Association Against Viral Diseases (DVV)

The global eradication of poliomyelitis by the year 2000 is an objective of the World Health Organization (WHO). Since 1998, after a period of 37 years of vaccination using live oral poliovirus vaccine (OPV), single use of inactivated poliovirus vaccine (IPV) has been recommended in Germany. The present epidemiological analysis shows the immunity of 3474 patients to poliovirus types 1, 2 and 3 by using a microneutralization assay. A non-age-specific evaluation of antibodies seroprevalence to poliovirus type 1 remained 81% and similarly, for poliovirus type 2 86% while the poliovirus type 3 decreased from 78% in 1990-1992 to 68% in 1997. In the important group of children aged 5-14 years, the prevalence of antibodies to type 3 decreased clearly from 74% in 1990 to 47% in 1997. The relatively favorable level of seroprevalence of antibody to type 2 in children aged 1-4 years (89%) indicates a good acceptance of vaccination programs. However, a good immunity to all 3 serotypes was not achieved by primary vaccination. The objective of a global eradication of poliomyelitis has not yet been be achieved. Great problems still exist, especially in Africa and Asia.

Seroprevalence and determinants of diphtheria, tetanus and poliomyelitis antibodies among adults in Berlin, Germany

The immunity levels against diphtheria, tetanus and poliomyelitis were investigated among blood donors (n = 2079) in Berlin. Of all participants, only 60% had full, long-term protection against diphtheria, 72% against tetanus, 87% against poliomyelitis type 1, 77% against poliomyelitis type 2 and 73% against type 3. There was a striking decrease of tetanus and diphtheria immunity levels by age. Immunity levels against tetanus were higher among males, whereas females were better protected against poliomyelitis. After adjusting for confounding effects in logistic regression diphtheria immunity in those aged <40 years was significantly higher in participants from East-Berlin, whereas the immunity levels against poliomyelitis were higher in West-Berlin. These differences reflect the different vaccination policies in East-Germany and West-Germany before 1989. There is a need to improve the immunity levels of the adult population in Berlin.

[A case of vaccination-induced polio]

CASE REPORT

We describe a 69 year-old female who became ill with polio after having changed the nappies of her grandchild who, six weeks earlier, had been vaccinated with oral live-vaccine against polio. Anamnesis and neurological status with limp paralysis in both legs oblige, with their implications, that the patient be isolated initially. Proof of poliomyelitis was to be found, in addition to typical medical findings, in the virus analysis in the stool, determined by polymerase chain reaction and in the discovery of antibodies from the serum by means of a neutralisation test. The neurological disorders could not be treated medically. The main priority was intensive physiotherapy. With walking aids the patient had only limited walking ability three months later.

CONCLUSION

Discussed are: the meaning of anamnesis and specific diagnosis of illness and immune deficiency, the morbidity and necessity for certain protection against children recently vaccinated with live-vaccine, also the provision for an individually structured plan for vaccination after satisfactory information.

Quantitative detection of neutralizing antibodies against polioviruses and non-polio enteroviruses (NPEV) using an automated microneutralization assay: a seroepidemiologic survey

A seroepidemiological survey for the assessment of immunity against polioviruses and non-polio enteroviruses (NPEV) seroprevalence was performed using a recently established automated microneutralization assay. The seroprevalences of neutralizing antibodies against Coxsackie viruses B1-B6, and A9, echoviruses 6, 9, 11, and 30, and polioviruses 1, 2, and 3 were investigated in serum samples collected over a period of 30 months (January 1990 to June 1992). Overall, NPEV seroprevalence ranged from 8.3% (Coxsackie virus B6) to 69.8% (echovirus 30). Age-related increases of seroprevalence were only observed for Coxsackie viruses B2 and A9. Relatively low antibody titres were found, the average antibody titre being the highest for Coxsackie virus B2 (1/55.4). The overall poliovirus seropositivity rate reached 80%. The highest seroprevalence was observed in the higher age groups (> or = 50 years). A relatively high proportion (7%) of individuals did not show neutralizing antibodies against all the three poliovirus serotypes. The results of our study have shown that, using an automated microneutralization assay, it is possible to perform seroepidemiological surveys in large patient populations. Until now, no comparable study concerning the NPEV seroprevalence has been performed.

Evaluation of a new automated microneutralization assay for the quantitative detection of neutralizing antibodies against enteroviruses

An automated microneutralization assay for the quantitative detection of neutralizing antibodies (NA) against polioviruses and non-polio enteroviruses (NPEV) using a pipetting roboter (Tecan RSP 5072) was established and compared to the conventional manually performed test procedure. The qualitative neutralizing antibody detection was not significantly influenced by the assay system (manual or automated assay). Concerning the quantitative antibody detection, two-fold titre differences between the two test systems were observed in only 2.3% of the 260 serum samples investigated. The intra-assay and inter-assay variability of the quantitative detection of neutralizing antibodies using the automated assay proved to be very low. The quantitative detection of neutralizing antibodies using an automated pipetting robot permitted the testing of large numbers of samples within a shorter period and with less labour intensity as compared to the manually performed assay. Therefore it represents a valuable alternative to the conventional microneutralization test, especially for the serodiagnosis of non-polio enterovirus infections in large sample collectives, assessment of immunity to polioviruses and for seroepidemiological surveys.