Doses Of Oral Polio Vaccine Research Articles

Highly Divergent Type 2 and 3 Vaccine-Derived Polioviruses Isolated from Sewage in Tallinn, Estonia

Highly divergent vaccine-derived polioviruses (VDPVs) have been isolated from sewage in Tallinn, Estonia, since 2002. Sequence analysis of VDPVs of serotypes 2 and 3 showed that they shared common noncapsid region recombination sites, indicating origination from a single trivalent oral polio vaccine dose, estimated to have been given between 1986 and 1998. The sewage isolates closely resemble VDPVs chronically excreted by persons with common variable immunodeficiency, but no chronic excretors have yet been identified in Estonia.

Vaccine Poliovirus Shedding and Immune Response to Oral Polio Vaccine in HIV-Infected and -Uninfected Zimbabwean Infants

With prolonged replication, attenuated polioviruses used in oral polio vaccine (OPV) can mutate into vaccine-derived poliovirus (VDPV) and cause poliomyelitis outbreaks. Individuals with primary humoral immunodeficiencies can become chronically infected with vaccine poliovirus, allowing it to mutate into immunodeficiency-associated VDPV (iVDPV). It is unclear if children perinatally infected with the human immunodeficiency virus (HIV), who have humoral as well as cellular immunodeficiencies, might be sources of iVDPV. We conducted a prospective study collecting stool and blood samples at multiple time points from Zimbabwean infants receiving OPV according to the national schedule. Nucleic acid extracted from stool was analyzed by real-time polymerase chain reaction for OPV serotypes. We analyzed 825 stool samples: 285 samples from 92 HIV-infected children and 540 from 251 HIV-uninfected children. Poliovirus shedding was similar after 0-2 OPV doses but significantly higher in the HIV-infected versus uninfected children after ≥ 3 OPV doses, particularly within 42 days of an OPV dose, independent of seroconversion status. HIV infection was not associated with prolonged or persistent poliovirus shedding. HIV infection was associated with significantly lower polio seroconversion rates. HIV infection is associated with decreased mucosal and humoral immune responses to OPV but not the prolonged viral shedding required to form iVDPV.

A study evaluating poliovirus antibodies and risk factors associated with polio seropositivity in low socioeconomic areas of Pakistan

BackgroundSeroprevalence studies provide important data on performance of immunization programs, susceptible groups and populations at-risk of future outbreaks. Identifying risk factors that affect seroconversion of the oral polio vaccine (OPV) will enable the polio eradication initiatives to increase seroprevalence. This paper describes the first population-based seroprevalence survey in Pakistan. MethodsThis study evaluated the seroprevalence of poliovirus (PV) types 1, 2, and 3 antibodies to OPV in an illustrative sample of 554 subjects 6–11 months of age in three geographic locations of Pakistan (Lahore, Karachi, and Peshawar) representing a low socioeconomic at-risk populations. Antibody titers were measured and sero protection rates and geometric median titers were compared among different geographic regions and populations, as were demographics and OPV vaccination history collected by questionnaire. Univariate and multivariate analyses were conducted on subject characteristics to assess for potential risk factors for failure to sero-convert. ResultsThe average seroprevalence of PV1, PV2, and PV3 was 96.0%, 87.9% and 86.7%, respectively. The lowest sero protection rate for all three serotypes was for Karachi with 90.2%, 73.8%, and 78.8% for PV1, PV2, and PV3, respectively. Significant regional variation in PV3 seroprevalence was found (range: 74.2–100%). In the univariate analysis, age, total and campaign OPV doses were associated with higher seroprevalence, whereas stunting, respondent education and diarrhea in the past six months were significant risk factors for failure to sero-convert. ConclusionsThese findings demonstrate consistently high levels of antibody response to PV1 and more geographically varied response to PV2 and PV3. Additionally, important risk factors affecting seropositivity were identified.

Progress towards eradication of poliomyelitis in Ghana: A review of the Eastern Region of Ghana from 1997 to 2010

Poliomyelitis is a highly-infectious viral disease affecting children under 15 years. One in 200 infections leads to irreversible paralysis and in 5 to 10% of such case, patients die from paralyzed breathing muscles. Ghana is at the verge of polio certification and the only reported case of wild polio virus in the Eastern Region was in 2003. We reviewed AFP data in the Eastern-Region to assess the progress towards interruption of polio virus transmission and identified opportunities for surveillance improvement. We reviewed records and conducted secondary data analysis of all AFP cases reported to the Region from 1997 to 2010. We assessed data quality, calculated AFP surveillance indicators, and described AFP cases by person, place, time and polio vaccination status. Completeness of case-based-forms was 90%. Of 306 AFP-cases reported, one wild polio virus was recorded; 59.2% were males aged < 5 years; 26.5% had right lower limb paralysis; 14% occurred in October and 52.6% had received 4 doses of oral polio-vaccine. The non-polio AFP rate ranged from 0.12 to 4.3/100,000 population and stool adequacy from 60 to 100%. The period prevalence of non-polio entero-viruses was 8.5% (26/306). There is sustained progress towards interruption of polio virus transmission in the region. However, opportunity remains to improve the completeness of case-based forms and the non-polio AFP rate. Key words: Acute flaccid paralysis, poliomyelitis, surveillance, eradication, vaccination, Ghana.

A Sri Lankan infant with vaccine associated acute flaccid paralysis

Global incidence of poliomyelitis has reduced by more than 99% since the Global Polio Eradication Initiative was launched in 1988 [1]. In par with the global trend, Sri Lanka has achieved great success with no reported cases since 1993, but still is not declared as a country which has eradicated polio due to prevalence of polioyomyelitis in neighbouring countries [2]. Countries which have eradicated polio use killed injectable polio vaccine (IPV), mainly because oral polio vaccine (OPV) can result in paralytic poliomyelitis. In literature review, we could not find any reported cases of paralytic poliomyelitis following vaccination in Sri Lanka. We report a case of acute flaccid paralysis following immunisation with first dose of OPV.

A survey for neutralizing antibodies to the three types of poliovirus among children in maiduguri, Nigeria

The milestone in polio eradication program is to protect effectively children aged 0-5 years against the three serotypes of poliovirus. It became necessary to measure the level of neutralizing antibodies to the three poliovirus types in an endemic State in Nigeria. Neutralizing antibodies to the poliovirus types among children aged 0-5 years was estimated using micro neutralization assay. Of 129 children, 99 (76.8%), 95 (73.6%), and 95 (73.6%) had neutralizing antibodies with the geometric mean titer of 42.7, 31.3, and 33.2 for the poliovirus type 1, 2, and 3, respectively. Fifty-three percent of the children were protected against the three types of poliovirus. Combination of poliovirus types 1 and 2, 1 and 3, and 2 and 3 were neutralized by 62.8, 58.9, and 61.2% of the children studied, respectively. Only poliovirus type 1 induced antibody titres ≥1:1,024. The number of children with neutralizing antibodies after receiving three doses was significantly higher than those who received one or two doses of oral polio vaccine (P ≤ 0.05). However, those who received more than three doses of oral polio vaccine showed no significant difference in their antibody response. The existence of immunity gap poses a risk of re-emergence of the paralytic poliovirus. The existence of unimmunized and unprotected children along with high birth rate could impede the success of polio vaccination in Nigeria. Elimination of non-compliance to polio vaccine, promotion of health education and documented evidence of vaccination of each child with the parents may facilitate the success of polio eradication program in Nigeria.

Immunologic Response to Oral Polio Vaccine in Human Immunodeficiency Virus–infected and Uninfected Zimbabwean Children

Poliovirus eradication is dependent on maintaining adequate community-wide levels of serologic protection. Many African countries with conditions that favor continued wild poliovirus propagation also have a high prevalence of pediatric human immunodeficiency virus (HIV) infection. Data are limited regarding the degree of serologic immunity conferred on HIV-infected children after immunization with oral polio vaccine (OPV). This was a cross-sectional study correlating HIV infection and neutralizing antibodies against poliovirus serotypes 1, 2, and 3 in 95 Zimbabwean children 2 months to 2 years of age, born to HIV-infected mothers, who received OPV according to the national schedule. HIV-infected children had significantly lower rates of seroconversion to all 3 poliovirus serotypes than HIV-uninfected children (60%, 67%, and 47% vs. 96%, 100%, and 82%, P = 0.001, 0.0003, and 0.015 for serotypes 1, 2, and 3 in HIV-infected and uninfected children, respectively, after ≥3 OPV doses). Among poliovirus seroconverters, HIV-infected children also had significantly lower geometric mean titers against serotypes 1 and 2 than HIV-uninfected children (geometric mean titers: 198 and 317 vs. 1193 and 1056, P = 0.032 and 0.050, for serotypes 1 and 2, respectively, after ≥3 OPV doses). In addition, HIV-infected children had significantly higher levels of total IgG and significantly lower CD4% and mean weight than HIV-uninfected children. Of note, none of the HIV-infected children were receiving antiretroviral therapy, and 71% had a CD4% indicating severe immunodeficiency. Pediatric HIV infection is associated with a poor serologic response to OPV, which could pose an obstacle to global polio eradication.

Measles control in Sub-Saharan Africa: South Africa as a case study

Due to intensified measles immunization efforts, measles mortality has decreased substantially worldwide, particularly in Sub-Saharan Africa (SSA). The World Health Organization (WHO) estimated a 92% decrease in measles-related deaths in the WHO AFRO region for the period 2000-2008. Recently, the AFRO region established a measles pre-elimination goal and experts have suggested engaging in a measles eradication campaign at the global level. However, recent large-scale outbreaks in many Sub-Saharan African countries present a challenge to measles control efforts. This paper examines measles immunization and the impact of measles supplemental immunization activities (SIAs) on routine immunization coverage in South Africa (SA). We reported on immunization coverage trends in SA for the period 2001-2010 at the province and district levels. The data included routine immunization for 1st and 2nd doses of measles vaccine (MCV1, MCV2), SIAs, 1st dose of Bacille Calmette-Guérin vaccine, 1st and 3rd doses of oral polio vaccine (OPV1, OPV3), 3rd dose of Diphtheria-Tetanus-Pertussis-Haemophilus-influenzae-B vaccine (DTP-Hib3), and the number of under-one-year-olds having completed a primary course of immunization (Imm1). A regression model looked at the SIA impact on routine coverage. Over the past decade, MCV1 and MCV2 coverage have increased nationally from 68% and 57% in 2001 to 95% and 83% in 2010, respectively. SIA coverage has remained at high levels, around 90%, over the same period. Substantial heterogeneity in MCV1 and MCV2 coverage is present across SA districts, with differences in coverage of 56% (MCV1) and 51% (MCV2) in 2010. In any given year, occurrence of SIAs was associated with a decrease in routine immunization coverage of MCV1, MCV2, OPV1, OPV3, DTP-Hib3, and Imm1, at the district level. The heterogeneity in measles vaccination coverage across SA districts challenges the goal of measles elimination in SA and SSA. The reduction in routine immunization coverage associated with the occurrence of SIAs raises the legitimate concern that SIAs may negatively impact health systems' functioning.

Inactivated polio vaccine and global polio eradication

2012 will mark the 24th year of WHO's Global Poliomyelitis Eradication Initiative. 1 WHOGlobal eradication of poliomyelitis by the year 2000. Week Epidemiol Rec. 1988; 63: 161-162 Google Scholar Eradication has proven more difficult than originally envisioned because of geopolitical events, such as war, social disruption, and political indifference; social and cultural issues, such as distrust of poliovirus vaccines and vaccinators; and the unanticipated emergence of virulent vaccine-derived polioviruses in many locations. Few of these obstacles have bewildered the scientific community as much as the low efficacy of the major weapon in the arsenal, trivalent oral polio vaccine (OPV) in regions with dense populations, high birthrates, and poor sanitation resulting from diarrhoea due to enteric pathogens, particularly rotaviruses, and perhaps nutritional deficiencies and other factors. 2 Patriarca PA Wright PF John TJ Factors affecting the immunogenicity of oral poliovirus vaccine in developing countries. Rev Infect Dis. 1991; 13: 926-939 Crossref PubMed Scopus (358) Google Scholar , 3 Myaux JA Unicomb L Besser RE et al. Effect of diarrhea on the humoral response to oral polio vaccination. Pediatr Infect Dis J. 1996; 15: 204-209 Crossref PubMed Scopus (38) Google Scholar This dilemma has been most frustrating in northern India where, in some crowded, resource-poor areas, the overall effectiveness of each trivalent OPV dose is estimated to be 10% and some children have developed paralytic polio after as many as ten doses. 4 Grassly NC Fraser C Wenger J et al. New strategies for the elimination of polio from India. Science. 2006; 314: 1150-1153 Crossref PubMed Scopus (216) Google Scholar Immunogenicity of supplemental doses of poliovirus vaccine for children aged 6–9 months in Moradabad, India: a community-based, randomised controlled trialSupplemental mOPV1 resulted in almost total seroprevalence against poliovirus type 1, which is consistent with recent absence of poliomyelitis cases; whereas seroprevalence against types 2 and 3 was expected for routine vaccination histories. The immunogenicity of IPV produced in India (Panacea) was similar to that of an internationally manufactured IPV (GSK). Intradermal IPV was less immunogenic. Full-Text PDF

Surveillance of acute flaccid paralysis in Akwa Ibom State, Nigeria 2004-2009

The last case of wild polio virus transmission occurred in Akwa Ibom state in October 2001; however, combination high routine immunization coverage with OPV, high quality AFP surveillance, mass immunization campaign in which two doses of potent oral polio vaccine is administered to eligible children and mop-up campaigns in areas with identified immunization or surveillance gaps has help the state in maintaining a free polio status for over ten years. This study was carried out to describe the characteristics of reported acute flaccid paralysis cases between 2004 and 2009, and to evaluate the performance of the acute flaccid paralysis surveillance system using indicators recommended by the World Health Organization. A retrospective study was conducted among children, 0-15 years, by the World Health Organization (WHO) and Epidemiology unit of State Ministry of Health (SMOH), Uyo. The demographic characteristics and the results of isolation and identification of polio and other enteroviruses in stool samples sent to the WHO Polio Laboratory Ibadan for cases was analyzed. A total of 521 cases of AFP (270 males and 251 females) aged 0 month to=15 years were reported by the surveillance system between 2004 and 2009. Those below 5 years of age accounted for 82.5% of cases reported and investigated. Of the 521 cases investigated 512 (98.3%) received at least three doses of oral polio vaccine, while 9(1.7) never received any oral polio vaccine (zero-dose). In all 5.1% of the isolates were Sabin, 7.9% non polio enterovirus (NPEV) and 2.3% were classified by national expert committee as compatible with poliomyelitis. There was consistent and steady increase in three critical indicators; Non polio AFP rate in children <15 years from 4.5 to 6.4 per 100,000 population, proportion of AFP cases with 2 stool specimens collected within 14 days of onset of paralysis from 57% in 2005 to 91% in 2009 and proportion of Local Government Areas (Districts) meeting both core indicators from 23% in 2005 to 87% in 2009. The highest numbers of cases were seen in the months of March, May and September. This study showed high levels of surveillance performance with some challenges in reverse the cold chain system, the continuation and sustained AFP case detection, prompt investigation and response, improvement in the reserve cold chain system would achieve optimal standards recommended by WHO and might provide a good model for the eradication of poliomyelitis.

O6-4.3 Poliomyelitis epidemic in Pointe-Noire, October–December 2010: troubled times ahead for global polio eradication?

IntroductionOn 4 November 2010, the Ministry of Health of the Republic of Congo declared a poliomyelitis outbreak in Pointe-Noire, the eastern economic capital. We conducted an outbreak investigation to describe...

Professor Natan Goldblum and the Combined Vaccination Program in Gaza

Blum et al. in November 2010 described the pioneering work of Natan Goldblum, a great Israeli virologist and innovator in polio immunization.1 Another important facet of his work was as a key contributor to development of the combined or sequential oral polio vaccine (OPV) and inactivated polio vaccine (IPV) programs used in the West Bank and Gaza since the late 1970s. Goldblum and Joseph Melnick from Baylor University were asked to consult in 1978 with the Israel Ministry of Health and the Gaza and West Bank public health services. During this time, I was the Coordinator for Health in the West Bank and Gaza for the Israeli Ministry of Health (from 1978-1994), with oversight responsibility for health in the West Bank and Gaza including immunization policy and other aspects of health services and training of Palestinian health providers. At that time, we faced continuing polio epidemics, mostly in Gaza where sanitary conditions were poor, despite high levels of OPV coverage. As an outcome of the discussions with Goldblum and Melnick, a new approach they recommended was jointly agreed to by the Israeli and Palestinian health officials. This accord expanded the routine immunization program from four doses of OPV by adding three doses of IPV given in a mixed sequence during the first year of life. This method was later dubbed the Gaza system. Coverage was soon greater than 85%, and catch-up campaigns were conducted for persons aged up to 18 years. Polio disappeared during the next two years and was effectively eradicated from these previously endemic areas.2 During the 1980s, Israel maintained an OPV-only policy, but with a trial IPV program in 2 districts of the country. In 1988, an outbreak of paralytic poliomyelitis occurred mainly among adolescents and young adults in one of these trial districts where the IPV-only policy was in effect (15 cases and one death). As a result of this episode, Israel adopted the Gaza system, and total eradication of polio was rapidly achieved.3,4 After eradication of polio in Gaza, the West Bank, and subsequently in Israel, the Gaza system was adopted and continues in other parts of the Middle East. A combined or sequential OPV and IPV program is an important policy option for polio control.5,6 In light of challenges in countries in which the virus is still endemic (Nigeria, India, Afghanistan, and Pakistan), with recent spread to other countries, the combination of OPV and IPV should again be considered for the end stage of polio eradication in remaining high-risk areas.7,8

Immunization coverage of children aged 0 to 5 years in Libreville (Gabon)

The strategies recently implemented in Gabon have been effective in improving immunization coverage. These include, in particular, the integration of the Expanded Programme on Immunization (EPI) in primary health care centers, the integration of immunization outside of EPI, immunization by peripheral health centers according to pre-set advanced strategies, and awareness and catch-up campaigns. This descriptive, cross-sectional survey was conducted from 1 October 2007 through 30 January 2008, throughout public- and private-sector health care centers in the town of Libreville. In the public sector, where health care is free, the study took place at the largest health facility in the country, the Hospital Center of Libreville (HCL), at Estuary Mélen Hospital (on the outskirts of Libreville), at Nkembo Hospital, which houses the EPI offices, and the 5 Maternal and Child Health centers (MCH) where vaccine monitoring is done. Monitoring in the private sector covered only the three largest clinics, where vaccine monitoring is done, all of which agreed to participate. After obtaining informed consent from the parents or guardian accompanying the child, a semi-structured interview according to a standardised questionnaire was conducted to collect socioeconomic and demographic data, including age, sex, recruitment site, place of residence, number of siblings, parental origin, ethnicity of head of household, type of family (couple or single parent), mother's age, level of education, employment and socio-economic status, as determined by the head of household's monthly income (in three categories: 1) low income, at or below the minimum wage, set at 80 000 FCFA (120 euros); 2) average income, from more than 80 000 FCFA to 300 000 FCFA (458 euros); and 3) high income over 300 000 FCFA. After the interview, the child's vaccination booklet was carefully examined to identify the types of antigen, number of doses administered, age at vaccination, and the regularity of the monitoring. Parents were asked to explain the reasons for any delays in or absences of vaccinations. EPI vaccines administered to children aged 0 to 11 months include: BCG (Calmette-Guérin bacillus); DPT3 (3rd combination dose for Diphtheria-Tetanus-Pertussis); Hib3 (3rdd dose of Haemophilus influenza b); OPV3 (3rd dose of oral polio vaccine); IPV3 (3rd dose of injectable polio vaccine, often in combination); HEB3 (3rd dose of Hepatitis B); yellow fever vaccine; and measles vaccine. The non-EPV vaccines for children aged 12 to 59 months included: HiB4; DPT4; HEB4; IPV4; MMR (combined Measles-Mumps-Rubella); meningococcal vaccine A and C; Typhim Vi (typhoid polysaccharide vaccine); and Pneumo 23 (pneumococcal vaccine.) The study included 1001 children: 533 boys (53.2%) and 468 girls (46.8%), for a sex ratio of 1.1. The mean age of the sample was 12.0±13.1 months, distributed as follows: 64.5% aged 0 to 11 months; 20.1% aged 12 to 24 months; and 15.4% aged 25 to 59 months. In all, 175 children (17.5%) came from the private sector, and 826children (82.5%) from the public sector. Both parents lived with 696 children (69.5%), while the remaining 305 children (30.5%) lived with their mother. The mothers' mean age was 26 years (min/max: 15/49 years); 61.3% had completed secondary education, 19.1% superior level, 10.6% primary level and 9.0% had no education at all. Almost 37% of mothers had some sort of paid employment. Household income was distributed as follows: low income for 18.6%, average income for 47.2%, and high income for 34.3% of the families interviewed. The average number of children under the age of 15 in a household was 3 (±2). Among children aged 0 to 11 months, the EPI antigens had the highest vaccination coverage rates, and these rates were higher in the private sector (more than 80% to 99% for some). Overall, the BCG scar was seen in 98.5% of all children; in the private sector 90.2% had received the third dose of the DTC/VPO-IPV vaccine, and in the public sector, 74.5%. The measles vaccination rate in the private sector was 82.5% compared with 64.4% in the public sector. The rates of coverage for antigens not included in the EPI varied from 50.8% to 74.2% in the private sector and from 6.2% to 32.5% in the public sector. The vaccine with the least coverage was the pneumococcal: only 3.2% and were vaccinated against this in the private sector and 0.8% in the public sector. The principal reasons for non-immunization were lack of financial resources (n=283, 28.3%), in particular, for booster up vaccines and those recommended by the EPI, lack of information (n=259, 25.9%), forgetfulness (n=217, 21.7%), neglect (n=113, 11.3%), sick child (n=80, 8%), vaccine not available (n=19, 1.9%), wrong information (n=15, 1.5%), travel (n=14, 1.4%), mother sick (n=12, 1.2%) and lack of time (n=18, 1.8%). Finally, the direct cost of good vaccination coverage for boosters was 42,245 FCFA (74 euros) in the public sector and 54,800 FCFA (84euros) in the private sector.

MRI findings in an infant with vaccine-associated paralytic poliomyelitis

Although acute flaccid paralysis is a manifestation observed in several neurologic and muscular disorders, vaccine-associated paralytic poliomyelitis (VAPP) is an exceedingly rare etiology. In the clinical setting of acute flaccid paralysis, MRI is useful in differentiating between VAPP and other conditions. Additionally, MRI can assess the extent of lesions. However, reports on MRI findings in VAPP are scarce in the pediatric radiology literature. We report a Brazilian infant who developed VAPP 40days after receiving the first dose of oral polio vaccine (OPV). MR images of the cervical and thoracic spinal cord showed lesions involving the anterior horn cell, with increased signal intensity on T2-weighted sequences. We would like to emphasize the importance of considering VAPP as a differential diagnosis in patients with acute flaccid paralysis and an MRI showing involvement of medulla oblongata or spinal cord, particularly in countries where OPV is extensively administered.

Multiple vaccinations and the risk of medically attended fever

Recent increases in the number of vaccinations recommended for infants have triggered concerns about the safety of multiple vaccinations. This study evaluated rates of medically attended fever after infant vaccination using computerized data from 1991 to 2000 from two large U.S. provider groups. The rate of medically attended fever within 7 days after vaccination was low (6.4 per 1000 vaccination visits) and did not increase during the decade. Higher rates of fever occurred during periods when a third dose of oral polio vaccine was used (1994–1995) and when a now-discontinued oral rotavirus vaccine was used (1998–1999). These findings offer reassurance that the multiple vaccinations introduced during the decade studied were not associated with increases in medically attended fever.

Antibody Response of Children Receiving Multiple Doses of Oral Polio Vaccine in Disease Free Area of India

Antibody Response of Children Receiving Multiple Doses of Oral Polio Vaccine in Disease Free Area of India

Plaque And Growth Characteristics Of Different Polioviruses Isolated From Acute Flaccid Paralysis In Northern Nigeria

To determine some virulent trait-related properties of poliovirus isolates from children with acute flaccid paralysis following vaccination with oral polio vaccine (OPV). Six polioviruses earlier characterised into wild, vaccine-derived and OPV-like were studied using the plaque morphology and growth kinetics at supra-optimal temperature. Department of Virology, University of Ibadan, Nigeria. Polio isolates from six children who developed acute flaccid paralysis following vaccinations with various doses of OPV were used. All the children were located in the Northern part of the country where poliovirus is still circulating. The two vaccine-derived polioviruses acquired wild type characteristics. All the six poliovirus isolates developed different forms of plaques ranging from tiny, small and large. The plaque formed could however not be used to identify the different isolates. Growth of the different isolates at supra-optimal temperature showed that the three wild polioviruses grew to a higher titre when compared with the Sabin 2 control. The two vaccine derived isolates behaved like the wild poliovirus while the OPV-like virus acquired an intermediate characteristics between wild and sabin. The wild polioviruses represented in this study are among the last vestiges of the circulating polioviruses found in the world. It is possible that the observed biological properties of wild types 1 and 3 described in the study are typical of the West African polioviruses. These properties will provide useful previews to the final identification of some important clinical isolates especially type 1 which may grow rapidly in cell culture.

Providing monovalent oral polio vaccine type 1 to newborns: findings from a pilot birth-dose project in Moradabad district, India.

Poliovirus transmission remained a public health challenge in western Uttar Pradesh, India in late 2005 and early 2006. In 2006, the India Expert Advisory Group for Polio Eradication concluded that, given the peak incidence of polio among children 6 to 12 months of age, a targeted birth dose of oral polio vaccine may be necessary to interrupt intense poliovirus transmission in high risk areas. The Government of Uttar Pradesh, the National Polio Surveillance Project and the United Nations Children's Fund (UNICEF) implemented a pilot birth-dose project aimed at identifying and vaccinating all newborns with a dose of oral polio vaccine within 72 hours of birth in an effort to evaluate operational feasibility and potential impact on population immunity. The project was piloted in Moradabad district: zone 7 in Moradabad City (urban setting), Kunderki block (rural setting) and in select birthing hospitals. Between July 2006 and February 2007, 9740 newborns were identified, of which 6369 (65%) were vaccinated by project personnel within 72 hours of birth. Project coverage (for total newborns vaccinated) ranged from 39% (in zone 7) to 76% (in Kunderki block) of the estimated number of newborns vaccinated during previous supplemental immunization activities. Birth-dose coverage among newborns was lower than expected. Expansion costs were estimated to be high, with marginal impact. The project, however, provided opportunities to strengthen newborn tracking systems which have increased the number of newborns and young infants vaccinated during supplemental immunization activities and enrolled in routine programmes.

Novel BTK mutation presenting with vaccine-associated paralytic poliomyelitis

Oral polio vaccine (OPV) has been used safely and efficiently for more than 40 years in preventive medicine. Vaccine-associated paralytic poliomyelitis (VAPP) is a rare adverse event of OPV due to reversion of the vaccine strain virus to a neurovirulent strain. VAPP can occur in healthy recipients or their close contacts. However, persons with primary humoral immunodeficiencies are at a much higher risk. X-linked agammaglobulinemia (XLA) is a prototypic humoral deficiency caused by mutations in the Bruton's tyrosine kinase (BTK) gene. In addition to susceptibility to bacterial infections, patients with XLA are especially prone to enteroviruses. Here, we describe the occurrence of VAPP in a 15-month old Iranian boy. The child had received four doses of OPV, administered at birth, 2, 4, and 6 months of age. The patient's infectious history was unremarkable. Laboratory evaluation revealed low levels of immunoglobulin G and CD19(+) B cells of less than 1% of the lymphocyte population. A novel insertion (c.685_686insTTAC) in the SH3 domain of the BTK gene was detected as the underlying cause. Immunodeficient recipients of OPV can excrete poliovirus vaccine strains for a long period and are at risk of developing flaccid paralysis. They could also serve as a source of reverted virulent poliovirus to be reintroduced into the general population. This patient presented for the first time with VAPP, without any history of other major infections in 15 months. This suggests that a negative history for recurrent infections does not exclude the presence of a primary defect in the immune system.

Booster vaccination at 6-8 years of age with a reduced antigen content dTpa-IPV vaccine is immunogenic and safe after priming with whole-cell pertussis vaccine

Pertussis vaccines containing reduced amounts of antigen have been considered primarily for use in adolescents and adults to date. We evaluated a reduced antigen content combined diphtheria tetanus acellular pertussis and inactivated polio vaccine (dTpa-IPV) in 6-8 years old children in Taiwan, who had received 4 doses of DTPw (combined diphtheria, tetanus, whole cell pertussis vaccine) and OPV (oral polio vaccine). One month after the booster dose, seroprotection rates and vaccine response rates to all antigens were at least 98.8%, and significant increases in antibody concentrations were observed. Booster vaccination was associated with minor local reactions and systemic symptoms. Symptoms of severe intensity did not occur, with the exception of local pain. The dTpa-IPV vaccine was immunogenic and well tolerated in 6-8 years old children and offers an alternative to the current use of tetanus and diphtheria vaccine and OPV in Taiwan, addressing the established need for repeated booster vaccinations against pertussis at the same time.