(1/258) Congo polio immunisation campaign gets go ahead.


(2/258) Paralytic poliomyelitis associated with live oral poliomyelitis vaccine in child with HIV infection in Zimbabwe: case report.

OBJECTIVE: To describe a complication of oral vaccination with live, attenuated poliomyelitis virus in a child infected with HIV. DESIGN: Case report. SETTING: Teaching hospital in Harare, Zimbabwe. SUBJECTS: A boy of 41/2 years and his mother. MAIN OUTCOME MEASURES: Results of clinical and laboratory investigations. RESULTS: Two weeks after receiving the second dose of oral poliomyelitis vaccine during national immunisation days the child developed paralysis of the right leg. He had a high titre of antibodies against poliovirus type 2, as well as antibodies against HIV-1, a low CD4 count, a ratio of CD4 to CD8 count of 0.47, and hypergammaglobulinaemia. He did not have any antibodies against diphtheria, tetanus, or poliovirus types 1 and 3, although he had been given diphtheria, tetanus, and pertussis and oral polio vaccines during his first year and a booster of the diphtheria, tetanus, and pertussis vaccine at 24 months. He had no clinical symptoms of AIDS, but his mother had AIDS and tuberculosis. CONCLUSION: Paralytic poliomyelitis in this child with HIV infection was caused by poliovirus type 2 after oral poliomyelitis vaccine.  (+info)

(3/258) A double-selective tissue culture system for isolation of wild-type poliovirus from sewage applied in a long-term environmental surveillance.

We describe a simple, cost-efficient, double-selective method for isolation of wild-type poliovirus from sewage samples containing vaccine polioviruses and other enteroviruses, with a detection limit of 18 to 50 PFU per 1 to 2 liters of sewage. By this method we were able to process 1,700 sewage samples collected between 1991 and 1996, from which 10,472 plaques were isolated, 41 of them being identified as wild-type polioviruses.  (+info)

(4/258) Induction of mucosal immunity by inactivated poliovirus vaccine is dependent on previous mucosal contact with live virus.

The inactivated poliovirus vaccine (IPV) is used for protection against poliomyelitis in The Netherlands. It is not clear, however, whether IPV vaccination can lead to priming of the mucosal immune system and the induction of IgA. It has been demonstrated that IPV vaccination is able to induce strong memory IgA responses in the serum of persons who have been naturally exposed to wild-type poliovirus. This has led to the hypothesis that IPV vaccination is able to induce poliovirus-specific IgA at mucosal sites in persons who have been previously primed with live poliovirus at mucosal sites. To test this hypothesis, the kinetics of the IgA response in serum and saliva after IPV vaccination were examined in persons previously vaccinated with oral poliovirus vaccine (OPV) or IPV. ELISA and enzyme-linked immunospot assays were used for the detection of poliovirus-specific IgA responses. In addition, B cell populations were separated on the basis of the expression of mucosal (alpha4beta7 integrin) and peripheral homing receptors (L-selectin). Parenteral IPV vaccination was able to boost systemic and mucosal IgA responses in previously OPV-vaccinated persons only. None of the previously vaccinated IPV recipients responded with the production of IgA in saliva. In agreement with this finding, a large percentage of the poliovirus-specific IgA-producing lymphocytes detected in previous OPV recipients expressed the alpha4beta7 integrin. It is concluded that IPV vaccination alone is insufficient to induce a mucosal IgA response against poliovirus. In mucosally (OPV-) primed individuals, however, booster vaccination with IPV leads to a strong mucosal IgA response.  (+info)

(5/258) Detection of poliovirus circulation by environmental surveillance in the absence of clinical cases in Israel and the Palestinian authority.

The global eradication of poliomyelitis, believed to be achievable around the year 2000, relies on strategies which include high routine immunization coverage and mass vaccination campaigns, along with continuous monitoring of wild-type virus circulation by using the laboratory-based acute flaccid paralysis (AFP) surveillance. Israel and the Palestinian Authority are located in a geographical region in which poliovirus is still endemic but have been free of poliomyelitis since 1988 as a result of intensive immunization programs and mass vaccination campaigns. To monitor the wild-type virus circulation, environmental surveillance of sewage samples collected monthly from 25 to 30 sites across the country was implemented in 1989 and AFP surveillance began in 1994. The sewage samples were processed in the laboratory with a double-selective tissue culture system, which enabled economical processing of large number of samples. Between 1989 and 1997, 2,294 samples were processed, and wild-type poliovirus was isolated from 17 of them in four clusters, termed "silent outbreaks," in September 1990 (type 3), between May and September 1991 (type 1), between October 1994 and June 1995 (type 1), and in December 1996 (type 1). Fifteen of the 17 positive samples were collected in the Gaza Strip, 1 was collected in the West Bank, and 1 was collected in the Israeli city of Ashdod, located close to the Gaza Strip. The AFP surveillance system failed to detect the circulating wild-type viruses. These findings further emphasize the important role that environmental surveillance can play in monitoring the eradication of polioviruses.  (+info)

(6/258) Comparison of enterovirus-specific cellular immunity in two populations of young children vaccinated with inactivated or live poliovirus vaccines.

Enterovirus-specific cellular immunity was studied in Estonian and in Finnish children at the age of 9 months. The aim was to evaluate the level of responsiveness in two neighbouring countries with different poliovirus immunization practices and striking differences in the incidence of insulin-dependent diabetes mellitus (IDDM), a disease in which early enterovirus infections are an aetiological risk factor. The Estonian children immunized with live attenuated polio vaccine had stronger T cell responses to coxsackievirus B4 and poliovirus type 1 when compared with Finnish children immunized with inactivated polio vaccine (median stimulation indices 10.4 and 6.3 in Estonian children and 1.9 and 2.9 in Finnish children, respectively; P < 0.05). Lymphocytes stimulated by poliovirus type 1 antigen expressed interferon-gamma (IFN-gamma) mRNAs, which strongly correlated with the level of proliferation responses. Lymphocytes of Estonian children had a tendency towards stronger expression of IFN-gamma upon poliovirus challenge when compared with Finnish children. The number of children who had experienced coxsackievirus B infections, as determined by the presence of neutralizing antibodies, did not differ between Estonian and Finnish children. The results show that Finnish children have weaker cellular immunity against enteroviruses at the age of 9 months compared with Estonian children at the same age. This is most probably due to the difference in polio vaccination schedules; in Estonia live poliovirus vaccine is used and given at earlier ages than the inactivated vaccines in Finland. This leads to stronger T cell immunity which cross-reacts with other enterovirus serotypes. This may explain the lower incidence of IDDM in Estonia by providing effective protection against diabetogenic enterovirus strains in Estonian children.  (+info)

(7/258) Safety and immunogenicity of Haemophilus influenzae-tetanus toxoid conjugate vaccine given separately or in combination with a three-component acellular pertussis vaccine combined with diphtheria and tetanus toxoids and inactivated poliovirus vaccine for the first four doses.

The purpose of this randomized, controlled trial was to assess the safety and immunogenicity of a three-component acellular pertussis vaccine combined with diphtheria and tetanus toxoids and inactivated poliovirus vaccine given either separately or combined as a single injection with a Haemophilus influenzae type b-tetanus toxoid conjugate vaccine. A total of 180 infants were immunized at 2, 4, and 6 months of age; 129 were given a booster dose at 16-19 months of age. Vaccine-associated adverse events were similar whether the vaccines were combined as a single injection or given separately. There were no differences in levels of antibodies to Bordetella pertussis antigens (pertussis toxoid, filamentous hemagglutinin, and pertactin), diphtheria toxoid, or the three poliovirus types. The tetanus antitoxin level after the primary three-dose series was higher in recipients of the combined vaccine (2.37 IU/mL) than in recipients of the separate injections (1.32 IU/mL; two-sided P = .0001). In contrast, combined vaccine recipients had lower levels of antibody to H. influenzae type b polysaccharide after the third dose (1.57 microg/mL) than did those given separate injections (3.22 microg/mL; two-sided P = .0026). The antibody levels were not significantly different before or 1 month after the booster dose (32.9 microg/mL vs. 47.8 microg/mL, respectively; two-sided P = .07). We conclude that the vaccines were immunogenic and well tolerated. Despite lower levels of antibody to the H. influenzae type b polysaccharide after the primary three-dose series, mixing of the vaccines in a single syringe likely induced immunologic priming, as suggested by the high antibody levels after the booster dose.  (+info)

(8/258) Progress toward poliomyelitis eradication during armed conflict--Somalia and southern Sudan, January 1998-June 1999.

In 1988, the Regional Committee of the World Health Organization (WHO) for the Eastern Mediterranean Region adopted a resolution to eliminate poliomyelitis from the region by 2000. Somalia and parts of southern Sudan have persons living in areas where there is ongoing armed conflict and poor infrastructure (e.g., health-care facilities, schools, roads, and power plants). Under these conditions, conducting National Immunization Days (NIDs) and acute flaccid paralysis (AFP) surveillance is difficult. This report summarizes NIDs in Somalia during 1997 and 1998 and in southern Sudan during 1998 and 1999 and establishment of AFP surveillance in northern Somalia and southern Sudan.  (+info)