Improved genotyping vaccine and wild-type poliovirus strains by restriction fragment length polymorphism analysis: clinical diagnostic implications. (1/134)

The combination of preventive vaccination and diagnostic typing of viral isolates from patients with clinical poliomyelitis constitutes our main protective shield against polioviruses. The restriction fragment length polymorphism (RFLP) adaptation of the reverse transcriptase (RT)-PCR methodology has advanced diagnostic genotyping of polioviruses, although further improvements are definitely needed. We report here on an improved RFLP procedure for the genotyping of polioviruses. A highly conserved segment within the 5' noncoding region of polioviruses was selected for RT-PCR amplification by the UC(53)-UG(52) primer pair with the hope that it would be most resistant to the inescapable genetic alteration-drift experienced by the other segments of the viral genome. Complete inter- and intratypic genotyping of polioviruses by the present RFLP method was accomplished with a minimum set of four restriction endonucleases (HaeIII, DdeI, NcoI, and AvaI). To compensate for potential genetic drift within the recognition sites of HaeIII, DdeI, or NcoI in atypical clinical samples, the RFLP patterns generated with HpaII and StyI as replacements were analyzed. The specificity of the method was also successfully assessed by RFLP analysis of 55 reference nonpoliovirus enterovirus controls. The concerted implementation of these conditional protocols for diagnostic inter- and intratypic genotyping of polioviruses was evaluated with 21 clinical samples with absolute success.  (+info)

Routine vaccinations and child survival: follow up study in Guinea-Bissau, West Africa. (2/134)

OBJECTIVE: To examine the association between routine childhood vaccinations and survival among infants in Guinea-Bissau. DESIGN: Follow up study. PARTICIPANTS: 15 351 women and their children born during 1990 and 1996. SETTING: Rural Guinea-Bissau. MAIN OUTCOME MEASURES: Infant mortality over six months (between age 0-6 months and 7-13 months for BCG, diphtheria, tetanus, and pertussis, and polio vaccines and between 7-13 months and 14-20 months for measles vaccine). RESULTS: Mortality was lower in the group vaccinated with any vaccine compared with those not vaccinated, the mortality ratio being 0.74 (95% confidence interval 0.53 to 1.03). After cluster, age, and other vaccines were adjusted for, BCG was associated with significantly lower mortality (0.55 (0.36 to 0.85)). However, recipients of one dose of diphtheria, tetanus, and pertussis or polio vaccines had higher mortality than children who had received none of these vaccines (1.84 (1.10 to 3.10) for diphtheria, tetanus, and pertussis). Recipients of measles vaccine had a mortality ratio of 0.48 (0.27 to 0.87). When deaths from measles were excluded from the analysis the mortality ratio was 0.51 (0.28 to 0.95). Estimates were unchanged by controls for background factors. CONCLUSIONS: These trends are unlikely to be explained exclusively by selection biases since different vaccines were associated with opposite tendencies. Measles and BCG vaccines may have beneficial effects in addition to protection against measles and tuberculosis.  (+info)

The vaccine origin of the 1968 epidemic of type 3 poliomyelitis in Poland. (3/134)

A clear association was demonstrated between the use of USOL-D-bac type 3 poliovirus live-attenuated vaccine and the 1968 poliomyelitis epidemic in Poland. The epidemic followed small-scale trials with Sabin and USOL-D-bac type 3 vaccine strains carried out in seven countries including Poland. Factors that might have contributed to the genesis and development of the epidemic were the pattern of virus excretion from vaccinees, mutations found in viruses from the epidemic, and the particular vaccination policies in Poland during the previous years. These findings may provide essential insights into the strategies for stopping polio immunisation once wild poliovirus has been eradicated.  (+info)

Immunity to poliomyelitis in The Netherlands. (4/134)

Despite a vaccination coverage rate of 97%, several poliomyelitis outbreaks occurred in the Netherlands during the last three decades, all among sociogeographically clustered, unvaccinated persons. Therefore, to eradicate polio, insight into poliomyelitis immunity is particularly useful. In 1995-1996, the authors conducted a population-based study and determined neutralizing antibodies against poliovirus types 1, 2, and 3 in 9,274 sera from the general population and from religious groups rejecting vaccination. In the general population, the antibody prevalence (>/=1:8) was 96.6% (95% confidence interval (CI): 95.9, 97.2), 93.4% (95% CI: 92.3, 94.5), and 89.7% (95% CI: 88.3, 91.0) for poliovirus types 1, 2, and 3, respectively. Antibodies persisted for long periods in persons with natural immunity as well as in persons whose immunity was induced by inactivated polio vaccine. In Orthodox Reformed persons, the antibody prevalence of poliovirus types 1, 2, and 3 was 65.0% (95% CI: 57.2, 72.9), 59.0% (95% CI: 40.1, 77.9), and 68.7% (95% CI: 65.2, 72.2), respectively. The recent outbreaks clearly affected the seroprevalence profiles of Orthodox Reformed groups but not the general population. At present, there is an insufficient social and political basis for mandatory vaccination; therefore, global eradication of poliovirus seems to be the only way to protect these Orthodox Reformed persons against future poliomyelitis outbreaks.  (+info)

No evidence of HIV and SIV sequences in two separate lots of polio vaccines used in the first U.S. polio vaccine campaign. (5/134)

We obtained sealed vials of two different polio vaccine lots, expiration date 1955, which were used in the first U.S. polio vaccine campaign. These early lots were pulled from the market because they contained live infectious poliovirus which caused polio in some of the vaccines. Theoretically, these vaccines could have contained other infectious retroviruses, including HIV. No viral sequences were detected using RT-PCR analyses with primers capable of amplifying chimpanzee SIV and HIV-1-related viruses nor with primers for macaque SIV, sooty mangabey SIV, and HIV-2-related viruses. Poliovirus sequences were readily amplified by RT-PCR, suggesting that the technique used would have detected SIV or HIV sequences, if present.  (+info)

Humoral immunity to viral and bacterial antigens in lymphoma patients 4-10 years after high-dose therapy with ABMT. Serological responses to revaccinations according to EBMT guidelines. (6/134)

The aim of this study was to investigate the late effects of ABMT on the immune system with regard to protective humoral immunity against common antigens and responses to recall antigens (vaccines). The vaccines were given according to EBMT guidelines from 1995. The protocol included 35 patients with malignant lymphoma in CR 4-10 years after ABMT, and 35 controls. The results show that prior to ABMT the proportion of patients with protective immunity against poliomyelitis, tetanus and diphtheria was similar to that of controls. At study entry 4-10 years after ABMT, the proportion of patients with protective immunity against poliomyelitis and diphtheria was reduced, while all patients maintained protection against tetanus. A significant decrease in geometric mean antibody concentrations or titres was observed against all three antigens during this period. Serum levels of antibodies against different pneumococcal serotypes were lower in the patients than in the controls prior to vaccination. The responses to pneumococcal vaccination, which is considered to be a T cell-independent vaccine, were studied. Unlike controls, a minority of patients achieved protective levels of antibodies after a single vaccination. Despite persistent levels of protective antibodies in many patients post ABMT, secondary booster responses after one vaccination with T cell-dependent vaccines (tetanus, diphtheria and polio) were absent. In conclusion, this study shows that post ABMT, a full re-vaccination program was necessary to mount responses comparable to those observed after a single vaccination in controls.  (+info)

Poliovirus circulation among schoolchildren during the early phase of the 1992-1993 poliomyelitis outbreak in The Netherlands. (7/134)

During the 1992-1993 outbreak of poliomyelitis in The Netherlands, we examined 866 childrenat 7 schools for evidence of infection with the outbreak virus, poliovirus type 3(PV3), to determine the extent of the outbreak and the protection of the herd immunity. Seventy-seven children (8.9%) showed evidence of recent wild-type PV3 infection, as determined by virus isolation and/or poliovirus type-specific IgM assay. Most infected children lived in the same area as the index case patient, attended an orthodox-reformed (OR) primary school, and had not been vaccinated. At the OR school, as many as 22% of children immunized with inactive poliovirus vaccine were found to have evidence of recent infection, which is a significantly lower rate than that among unvaccinated children (59.5%). No evidence of vaccination was seen in 25.5%-43.1% of children at OR schools. Seroprevalence of antibodies against the 3 types of poliovirus suggested that no poliovirus circulation had occurred between the 1978 and 1992-1993 outbreaks.  (+info)

Thirty-five year mortality following receipt of SV40- contaminated polio vaccine during the neonatal period. (8/134)

Early poliovirus vaccines, both inactivated and live attenuated, were inadvertently contaminated with simian virus 40 (SV40), a monkey virus known to be oncogenic for newborn hamsters. Although large epidemiologic studies have not identified an elevated cancer risk in persons who received SV40-contaminated vaccines, fragments of SV40 DNA have recently been identified in certain human tumours. We report the follow-up of a cohort of 1073 persons, unique because they received SV40-contaminated poliovirus vaccines as newborns in 1961-63. A previous report of the status of these subjects as of 1977-79 identified 15 deaths, none due to cancer. The present study utilized the National Death Index to identify deaths in the cohort for the years 1979-96. Expected deaths were calculated from Cleveland area sex-, age-, race- and year-specific mortality rates. Increased mortality from all causes was not found. 4 deaths from cancer were found compared to 3.16 expected (P = 0.77). However, 2 deaths from testicular cancer occurred, compared to 0.05 expected (P = 0.002), which may be a chance finding due to multiple comparisons. There were 2 deaths due to leukaemia, a non-significant finding, and no deaths due to tumours of the types putatively associated with SV40. Although these results are, for the most part, consistent with other negative epidemiologic investigations of risks from SV40-contaminated vaccines, further study of testicular cancer may be warranted, and it will be important to continue monitoring this cohort which is now reaching middle-age.  (+info)