Severe immune thrombocytopenia following diphtheria, tetanus, pertussis and polio vaccination in a 36-year-old Caucasian woman: a case report.

BACKGROUND: Immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by low platelet counts and increased bleeding risk. The disease may be induced by other disorders, including malignancies, autoimmune diseases, infectious agents or drugs. However, ITP has also been described following vaccinations, such as the measles-mumps-rubella vaccination. In rare cases, ITP may occur in children who received a DTaP-IP (diphtheria, tetanus, acellular pertussis vaccine and inactivated poliovirus) vaccine. Hereinafter, we report the first well-documented cases of ITP in an adult patient in the temporal context of a DTaP-IP vaccination. CASE PRESENTATION: This case report attempts to capture the life-threatening picture of a 36-year-old otherwise healthy Caucasian woman with newly diagnosed severe immune thrombocytopenia in the temporal context of a DTaP-IP vaccination. Four days after receiving the vaccine, the women presented to her primary care physician with malaise, fever and recurrent epistaxis. Clinical examination revealed oral petechiae, ecchymoses, and non-palpable petechiae on both legs. The patient was immediately referred to a local hematology unit where she developed hematuria and an intestinal bleeding (WHO Bleeding Grade III) requiring multiple transfusions. After receiving oral corticosteroids and intravenous immunoglobulins, her platelets gradually recovered. Common causes of secondary ITP were ruled out by laboratory investigations, bone marrow and peripheral blood examinations. This raises the possibility of a (secondary) vaccination-associated thrombocytopenia. To the best of our knowledge, this is the first well-documented case of a DTaP-IP vaccination-related ITP in an adult patient in the English literature. CONCLUSION: Although a causal connection between both entities may not be established, we would like to raise awareness in clinicians that ITP following DTaP-IP vaccinations is potentially not limited to children, but may also occur in adults. Users of DTaP-IP booster vaccines should be alert of the possibility of such adverse reactions.

Vaccine Allergy? Skin Testing and Challenge at a Tertiary Pediatric Hospital in Melbourne, Australia.

BACKGROUND: The rate of true vaccine allergy is unknown. Children with potential IgE-mediated adverse events following immunization (AEFI) should undergo allergy investigation that may include skin testing or challenge. Previous protocols tend to be highly conservative and often suggest invasive testing for all, a practice not evidence based, technically difficult, and unpleasant in children. It has more recently been suggested that skin testing may be restricted to those with allergic-like events within the first hour and those with a history of anaphylaxis. OBJECTIVE: We aimed to describe the outcome of vaccine skin testing and challenge in children referred to a tertiary pediatric hospital with a potential IgE-mediated AEFI. The secondary aim was to identify any significant risk factors for vaccine allergy. METHODS: A retrospective review of all children (<18 years) who underwent vaccine skin testing (skin prick testing or intradermal testing [IDT]) or challenge over a 5-year period (May 1, 2011, to April 30, 2016) at the Royal Children's Hospital Melbourne is presented. RESULTS: There were 95 admissions in 73 children. Eight percent (6 of 73) of children had confirmed vaccine allergy (positive skin testing or challenge to the index vaccination). Two had positive IDT to a suspect vaccine but challenge negative to an alternative brand vaccine. Two had negative IDT but subsequent positive challenge and two had immediate urticaria on challenge without prior skin testing. All children in the positive group either had index reaction within 15 minutes of vaccination or had history consistent with anaphylaxis. CONCLUSIONS: The vast majority of children (92%) presenting with a potential IgE-mediated AEFI are able to tolerate challenge to a suspect vaccine without reaction. We present our investigation protocol recommending skin testing in all children with anaphylaxis and challenge with a suspect vaccine if negative testing or previous nonanaphylactic potential IgE-mediated AEFI.

[False beliefs about vaccines]. / Falsas creencias sobre las vacunas.

Vaccines are an essential tool for the prevention of infectious diseases. However, false ideas and rumours with no scientific foundation about their possible negative effects may dissuade people from being vaccinated, with the consequent risks for the health of the population. The objective of this article is to evaluate the origin and the arguments of some of the most frequent mistaken ideas and rumours about the possible adverse effects of vaccines. Some clearly established adverse effects are presented, as well as false beliefs about various vaccines and potential harm to health. Vaccines, like any drug, can cause adverse effects, but the possible adverse effects of vaccination programs are clearly lower than their individual (vaccinated) and collective benefits (those vaccinated and those who cannot be vaccinated for medical reasons). The possible adverse effects attributable to vaccines should be detected by powerful and well-structured pharmacovigilance systems.

Atypical aluminium patch tests in children with persistent itching postvaccinal nodules.

Persistent itching nodules related to aluminium-adsorbed vaccines are well known in children with frequent positive patch tests to aluminium when tested. We report two cases of children with persistent postvaccination nodules who presented with atypical eruptions after aluminium patch tests.

Post-marketing surveillance study to assess the safety and tolerability of an Inactivated Poliomyelitis Vaccine in Indian children.

OBJECTIVE: To evaluate the incidence of adverse events following administration of an Inactivated poliomyelitis vaccine (IPV) manufactured by Serum Institute of India Pvt. Ltd., Pune, India. METHODS: A single 0.5 ml dose of the IPV was administered intramuscularly to children attending private clinics or out-patient department of hospitals for routine immunization across different cities in India. They were observed over a period of 30 d for local or systemic adverse events and rare case of anaphylaxis, if any. RESULTS: A total of 2210 children were enrolled of which 2120 children received the vaccine within primary immunization series and 90 children received booster dose. The common adverse events reported were pain, erythema, swelling and fever. No serious adverse event was reported during the study period. CONCLUSIONS: Poliomyelitis vaccine (Inactivated) manufactured by Serum Institute of India Pvt. Ltd., Pune can be safely administered to children following the Expanded Programme on Immunization or World Health Organization recommended immunization schedule.

A randomized study of fever prophylaxis and the immunogenicity of routine pediatric vaccinations.

OBJECTIVE: Prophylactic antipyretic use during pediatric vaccination is common. This study assessed whether paracetamol or ibuprofen prophylaxis interfere with immune responses to the 13-valent pneumococcal conjugate vaccine (PCV13) given concomitantly with the combined DTaP/HBV/IPV/Hib vaccine. METHODS: Subjects received prophylactic paracetamol or ibuprofen at 0, 6-8, and 12-16 h after vaccination, or 6-8 and 12-16 h after vaccination at 2, 3, 4, and 12months of age. At 5 and 13months, immune responses were evaluated versus responses in controls who received no prophylaxis. RESULTS: After the infant series, paracetamol recipients had lower levels of circulating serotype-specific pneumococcal anticapsular immunoglobulin G than controls, reaching significance (P<0.0125) for 5 serotypes (serotypes 3, 4, 5, 6B, and 23F) when paracetamol was started at vaccination. Opsonophagocytic activity assay (OPA) results were similar between groups. Ibuprofen did not affect pneumococcal responses, but significantly (P<0.0125) reduced antibody responses to pertussis filamentous hemagglutinin and tetanus antigens after the infant series when started at vaccination. No differences were observed for any group after the toddler dose. CONCLUSIONS: Prophylactic antipyretics affect immune responses to vaccines; these effects vary depending on the vaccine, antipyretic agent, and time of administration. In infants, paracetamol may interfere with immune responses to pneumococcal antigens, and ibuprofen may reduce responses to pertussis and tetanus antigens. The use of antipyretics for fever prophylaxis during infant vaccination merits careful consideration. ClinicalTrials.gov identifier: NCT01392378https://clinicaltrials.gov/ct2/show/NCT01392378?term=NCT01392378&rank=1.

An open-label, randomized study of a 9-valent human papillomavirus vaccine given concomitantly with diphtheria, tetanus, pertussis and poliomyelitis vaccines to healthy adolescents 11-15 years of age.

BACKGROUND: A 9-valent human papillomavirus (9vHPV) vaccine has recently been reported to be safe and highly efficacious against infection and disease related to HPV6/11/16/18/31/33/45/52/58. We evaluated the immunogenicity and safety of the 9vHPV vaccine administered concomitantly with REPEVAX (diphtheria, tetanus, acellular pertussis and inactivated poliomyelitis vaccine). METHODS: This open-label, randomized, multicenter study enrolled 1054 males and females ages 11-15 years. Subjects were randomly assigned to each group in a 1:1 ratio. Subjects received a 0.5 mL dose of 9vHPV vaccine intramuscularly at day 1, months 2 and 6 and a 0.5 mL dose of REPEVAX either on day 1 (concomitant vaccination group; n = 526) or at month 1 (nonconcomitant vaccination group, n = 528). Serologic responses for each vaccine component were tested by 1-sided tests of noninferiority between groups. Systemic and injection-site adverse experiences (AEs) and serious AEs were monitored. RESULTS: Noninferiority of anti-HPV geometric mean titers and seroconversion rates for all 9vHPV antigens were demonstrated for the concomitant group compared with the nonconcomitant group. Seroconversion rates for the 9vHPV vaccine types were ≥99.8% in both groups at month 7. For REPEVAX, noninferiority of immune response was established for diphtheria, tetanus, all polio and pertussis antigens for both groups. There were no vaccine-related serious AEs. CONCLUSION: Overall, concomitant administration of 9vHPV vaccine and REPEVAX was generally well tolerated and did not interfere with the immune response to either vaccine. This strategy would minimize the number of visits required to deliver each vaccine individually.

Internações sensíveis à atenção primária específicas de mulheres / Sensitive female-specific hospitalization in primary care

Objetivou-se analisar as internações por condições sensíveis à atenção primária (ICSAP) específicas em mulheres e os fatores que determinam ou influenciam a ocorrência dessas internações (fatores socioeconômicos, sociodemográficos e controle de saúde) por meio de um inquérito de morbidade hospitalar realizado com amostra de 429 mulheres internadas em hospitais conveniados ao Sistema Único de Saúde. O percentual de ICSAP foi 49,42% (n = 212), com destaque para as internações específicas do sexo feminino 19,35% (n = 83). Associaram ao risco de internar por CSAP: idade superior a 60 anos, baixa escolaridade, internação prévia, realização de controle regular de saúde, falta de vínculo com a Estratégia Saúde da Família (ESF) e ser gestante. As causas evidentes foram as condições relacionadas à gravidez, ao parto e ao puerpério e às inflamações nos órgãos pélvicos femininos. Os resultados sugerem falhas no atendimento ambulatorial que deveria ser oportuno e resolutivo no contexto da saúde da mulher.

The scope of this paper was to analyze female-specific sensitive hospitalization occurring in primary care conditions and factors that determine or affect the occurrence of such hospitalizations (social, economic and demographic factors; health control). Analysis was performed by surveys on hospital morbidity with a sample of 429 females attended in Unified Health System (SUS) contracted hospitals. The sensitive hospitalizations percentage in primary care reached 49.42% (n = 212), highlighting female-specific hospitalization at 19.35% (n = 83). Hospitalization risks comprised elderly people over sixty, low schooling, previous hospitalizations, normal health control, lack of association with the Family Health Strategy and pregnancy. Evident causes were related to conditions of pregnancy, childbirth, post-partum and inflammations of the female pelvic organs. Results suggested flaws in outpatient attendance that should be adequate and provide solutions in women’s health.

How common are long-lasting, intensely itching vaccination granulomas and contact allergy to aluminium induced by currently used pediatric vaccines? A prospective cohort study.

UNLABELLED: The frequency of long-lasting, intensely itching subcutaneous nodules at the injection site for aluminium (Al)-adsorbed vaccines (vaccination granulomas) was investigated in a prospective cohort study comprising 4,758 children who received either a diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b vaccine (Infanrix®, Pentavac®) alone or concomitant with a pneumococcal conjugate (Prevenar). Both vaccines were adsorbed to an Al adjuvant. Altogether 38 children (0.83 %) with itching granulomas were identified, epicutaneously tested for Al sensitisation and followed yearly. Contact allergy to Al was verified in 85 %. The median duration of symptoms was 22 months in those hitherto recovered. The frequency of granulomas induced by Infanrix® was >0.66 % and by Prevenar >0.35 %. The risk for granulomas increased from 0.63 to 1.18 % when a second Al-adsorbed vaccine was added to the schedule. CONCLUSION: Long-lasting itching vaccination granulomas are poorly understood but more frequent than previously known after infant vaccination with commonly used diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b and pneumococcal conjugate vaccines. The risk increases with the number of vaccines given. Most children with itching granulomas become contact allergic to aluminium. Itching vaccination granulomas are benign but may be troublesome and should be recognised early in primary health care to avoid unnecessary investigations, anxiety and mistrust.

Safety and immunogenicity of inactivated poliovirus vaccine based on Sabin strains with and without aluminum hydroxide: a phase I trial in healthy adults.

BACKGROUND: An inactivated poliovirus vaccine (IPV) based on attenuated poliovirus strains (Sabin-1, -2 and -3) was developed for technology transfer to manufacturers in low- and middle income countries in the context of the Global Polio Eradication Initiative. METHOD: Safety and immunogenicity of the Sabin-IPV was evaluated in a double-blind, randomized, controlled, phase I 'proof-of-concept' trial. Healthy male adults received a single intramuscular injection with Sabin-IPV, Sabin-IPV adjuvanted with aluminum hydroxide or conventional IPV. Virus-neutralizing titers against both Sabin and wild poliovirus strains were determined before and 28 days after vaccination. RESULTS: No vaccine-related serious adverse events were observed, and all local and systemic reactions were mild or moderate and transient. In all subjects, an increase in antibody titer for all types of poliovirus (both Sabin and wild strains) was observed 28 days after vaccination. CONCLUSION: Sabin-IPV and Sabin-IPV adjuvanted with aluminum hydroxide administered as a booster dose were equally immunogenic and safe as conventional IPV. EudraCTnr: 2010-024581-22, NCT01708720.

Safety and immunogenicity of 2 mixed primary infant immunization schedules of pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis, and Haemophilus influenzae Type B vaccines at 2, 4, and 6 months of age: a randomized controlled trial.

BACKGROUND: Two pentavalent infant vaccines that contain either 5 or 3 component acellular pertussis antigens are authorized in Canada. Because of changes in vaccine use by provinces over time and movement of families across jurisdictions, it is possible that children are exposed to different combination vaccines during the primary infant immunization schedule. The safety and immunogenicity of mixed primary infant schedules is unknown. METHODS: In a double-blind multicenter trial, 2-month-old healthy infants were randomized to 1 of 2 schedules at 2, 4, and 6 months of age (either Pediacel, Pediacel, Infanrix [PPI] or Infanrix, Pediacel, Pediacel [IPP]). Solicited local and systemic adverse events (AEs) were collected by parent diary on days 0 through 7; unsolicited AEs were collected for 31 days after each dose. Immune responses to polypolyribosylribitol phosphate capsular polysaccharide (PRP) (Haemophilus influenzae type b) and pertussis antigens were assessed before the first dose and 28 days after the 6 month (third) dose. RESULTS: In all, 127 infants were randomized to IPP and 126 to PPI. The percentage of children with anti-PRP responses ≥0.15 µg/mL after dose 3 was higher in the IPP than in the PPI group (98.3, 95% CI: 94.1, 99.8 vs. 86.1%, 95% CI: 78.6, 91.7, P < 0.001). Antipertussis toxin and anti-fimbriae 2 and 3 responses were statistically significantly higher in the IPP than in the PPI group. Higher filamentous hemagglutinin responses occurred in PPI than in IPP. No difference between groups was observed in pertactin responses.Systemic AEs were similar between the 2 vaccine schedules. Irritability (67.2 vs. 51.6, P = 0.014) and mild crying (35.2% vs. 23.0%, P = 0.037) were more common after the 6-month dose in the PPI compared with the IPP group, as were overall systemic reactions (any intensity) for the PPI group after this dose (80.0 vs. 68.0, P = 0.042). CONCLUSION: Mixed 2-, 4-, 6-month pentavalent infant vaccine schedules had different immunogenicity and reactogenicity, with a PPI schedule being more reactogenic, and less immunogenic for PRP and fimbriae 2 and 3 antigens at 7 months. It is preferable to complete the primary infant 3-dose vaccine series with the same vaccine, rather than considering infant vaccines as interchangeable.

Impacto económico de la introducción de la vacuna inactivada inyectable contra la poliomielitis en Colombia / Economic impact of introducing the injectable inactivated polio vaccine in Colombia

OBJETIVOS: Evaluar la relación costo-efectividad de la introducción de la vacuna inyectable contra la poliomielitis (VIP) en Colombia con respecto al sistema actual basado en el empleo de la vacuna oral (VOP). MÉTODOS: Se diseñó un modelo de Markov basado en una cohorte hipotética de recién nacidos que recibiría la VIP o la VOP con un seguimiento de dos años y estimaciones mensuales del número de casos de poliomielitis paralítica asociada con la vacuna (PPAV). El análisis del costo se realizó desde la perspectiva del asegurador (costos a lo largo de la vida) y la sociedad (casos de PPAV evitados y años de vida ajustados por discapacidad [AVAD] evitados). RESULTADOS: Entre 1988 y 1998 se aplicaron en Colombia 22,5 millones de dosis de la VOP y se detectaron nueve casos de PPAV, para una tasa de 4,0 ¥ 10-7 por dosis. Según el modelo, se podrían esperar entre 2 y 4 casos de PPAV en los dos años de seguimiento. El costo de tratar los casos de PPAV sería de US$ 302 008, con costos de vacunación con la VOP de US$ 737 037 y de US$ 5 527 777 con la VIP. La vacunación con la VIP permitiría evitar 64 AVAD con un costo de US$ 71 062 por AVAD evitado; evitar un caso de PPAV mediante la sustitución de la VOP por la VIP costaría entre US$ 1,8 millones y US$ 2,2 millones. CONCLUSIONES: La sustitución de la VOP por la VIP no es una medida efectiva en función del costo en Colombia, incluso si se sustituyera la vacuna celular contra la tos ferina, actualmente en uso, por una vacuna acelular combinada con una VIP.

OBJECTIVE: Evaluate the cost-effectiveness of introducing the injectable inactivated polio vaccine (IPV) in Colombia versus the current system based on the use of the oral vaccine (OPV). METHODS: A Markov model was designed, based on a hypothetical cohort of newborns that would receive the IPV or the OPV vaccine, with a two-year follow-up and monthly estimates of the number of cases of vaccine-associated paralytic poliomyelitis (VAPP) that would emerge. The cost was analyzed from the perspective of the insurer (costs throughout life) and society (cases of VAPP and disability-adjusted life years [DALYs] prevented). RESULTS: From 1988 to 1998, some 22.5 million doses of OVP were administered in Colombia and nine cases of VAPP were detected, for a rate of 4.0 ¥ 10-7 dose. According to the model, 2 to 4 cases of VAPP could be anticipated in the following two years. The cost of treating the VAPP cases would total US$302 008, with the cost of vaccination with OPV coming to US$737 037 and with IPV, US$5 527 777. Vaccination with IPV would prevent 64 DALYs, at a cost of US$71 062 per DALY prevented; preventing one case of VAPP by substituting OPV with IPV would cost between US$1.8 and US$2.2 million. CONCLUSIONS: Substituting OPV with IPV is not a cost-effective measure in Colombia, even if the cellular vaccine against whooping cough currently in use were replaced with an acellular vaccine combined with an IPV.

Vacunación antipoliomielítica en niños de la Ciudad de Buenos Aires / Antipoliomyelitic vaccination in children living in Buenos Aires City

A raíz de la presentación de un caso confirmado de poliomielitis paralítica por virus Sabin derivado (VSD) en niños de 15 meses se analizó la cobertura de vacunación antipoliomielítica en niños residentes en la Ciudad de Buenos Aires, durante el trienio 2006/2008. Se observó una mejora a lo largo del período analizado, pero sólo hubo valores superiores al 95 por ciento para la primera dosis. Aumentó la proporción de vacuna inactivada (IPV) en desmedro de la vacuna oral viva (OPV); en 2008, la cobertura con IPV primera dosis fue del 37,64 por ciento y del 19,48 por ciento para el ingreso escolar. La falta de inmunidad intestinal que se presenta en los niños vacunados con IPV, asociada a coberturas insatisfactorias condiciona un terreno propicio para la circulación de virus salvaje o VSD, lo cual favorece la aparición de casos de poliomielitis paralítica en niños no vacunados o inmunodeficientes.

Minimal change nephrotic syndrome in an 82 year old patient following a tetanus-diphteria-poliomyelitis-vaccination.

BACKGROUND: The most common cause of idiopathic nephrotic syndrome in children and younger adults is the minimal change nephrotic syndrome (MCNS). In the elderly MCNS is relatively uncommon. Over the last decade some reports suggest a rare but possible association with the administration of various vaccines. CASE PRESENTATION: A 82-year old Caucasian female presented with pronounced nephrotic syndrome (proteinuria of 7.1 g/d, hypoproteinemia of 47 g/l). About six weeks prior to admission, she had received a combination vaccination for tetanus, diphtheria and poliomyelitis as a booster-vaccination from her general practitioner. The renal biopsy revealed typical minimal change lesions. She responded well to the initiated steroid treatment. As through physical examination as well as extensive laboratory and imaging studies did neither find any evidence for malignancies nor infections we suggest that the minimal change nephrotic syndrome in this patient might be related to the activation of the immune system triggered by the vaccination. CONCLUSION: Our case as well as previous anecdotal reports suggests that vaccination and the resulting stimulations of the immune system might cause MCNS and other severe immune-reactions. Increased awareness in that regard might help to expand the database of those cases.

Safety and immunogenicity of a DTaP-IPV(Vero) (serum-free) combination vaccine in comparison to DTaP-IPV(Mkc) when administered simultaneously with Haemophilus influenzae type B conjugate vaccine (PRP-T) in children at 2, 3.5, 5 and 16 months of age.

In a phase III, double blind, randomized, noninferiority, multi-centre clinical trial, 817 infants were included and randomly assigned to vaccination with DTaP-IPV(Vero) (N=410) or DTaP-IPV(Mkc) (N=407) vaccines (Statens Serum Institut (SSI), Denmark) in the right thigh. All infants were vaccinated with Act-HIB (Sanofi Pasteur, France) in the left thigh at the same time. The vaccination schedule was 2, 3.5, 5 and 16 months and serum samples were obtained at 6, 16 and 17 months. The primary objective was to demonstrate noninferiority of DTaP-IPV(Vero) to DTaP-IPV(Mkc) as regards immunological protection against polio virus types 1, 2 and 3. Furthermore, the immunogenicity of all vaccine antigens and the safety profile of the vaccines were assessed. The study demonstrated that DTaP-IPV(Vero) was noninferior to DTaP-IPV(Mkc). All antibody concentrations/titres remained at an acceptable level from the end of the primary vaccination series (i.e. 2, 3.5 and 5 months) until the time of the booster vaccination at 16 months. A good booster response was, furthermore, demonstrated for all antigens. No vaccine-related serious adverse events and no injection site granulomas or swelling of the entire thigh occurred. The frequencies of local injection site erythema and swelling as well as systemic adverse events such as fever, irritability, somnolence and decreased appetite were low and acceptable in both treatment groups. In conclusion, DTaP-IPV(Vero) is immunogenic and safe for primary vaccination and for booster vaccination of healthy children.

Primary immunization of premature infants with gestational age <35 weeks: cardiorespiratory complications and C-reactive protein responses associated with administration of single and multiple separate vaccines simultaneously.

OBJECTIVE: To determine the incidence of cardiorespiratory events and abnormal C-reactive protein (CRP) level associated with administration of a single vaccine or multiple separate vaccines simultaneously. STUDY DESIGN: Prospective observational study on 239 preterm infants at > or =2 months of age in the neonatal intensive care unit (NICU). Each infant received either a single vaccine or multiple vaccines on one day. CRP levels and cardiorespiratory manifestations were monitored for 3 days following immunization. RESULTS: Abnormal elevation of CRP level occurred in 85% of infants administered multiple vaccines and up to 70% of those given a single vaccine. Overall, 16% of infants had vaccine-associated cardiorespiratory events within 48 hours postimmunization. In logistic regression analysis, abnormal CRP values were associated with multiple vaccines (OR, 15.77; 95% CI 5.10-48.77) and severe intraventricular hemorrhage (IVH) (OR, 2.28; 95% CI 1.02-5.13). Cardiorespiratory events were associated marginally with receipt of multiple injections (OR, 3.62; 95% CI 0.99-13.25) and significantly with gastroesophageal reflux (GER) (OR, 4.76; 95% CI 1.22-18.52). CONCLUSION: CRP level is expected to be elevated in the 48 hours following immunization. In a minority of infants immunized, cardiorespiratory events were associated with presumed need for intervention. Underlying medical conditions and possibly multiple injections are associated with cardiorespiratory events. Precautionary monitoring following immunizations is warranted.

Is there a role for SV40 in human cancer?

The question of whether Simian Virus 40 (SV40) can cause human tumors has been one of the most highly controversial topics in cancer research during the last 50 years. The longstanding debate began with the discovery of SV40 as a contaminant in poliovirus vaccine stocks that were used to inoculate approximately 100 million children and adults in the United States between 1955 and 1963, and countless more throughout the world. Concerns regarding the potential health risk of SV40 exposure were reinforced by studies demonstrating SV40's potential to transform human cells and promote tumor growth in animal models. Many studies have attempted to assess the relationship between the potential exposure of humans to SV40 and cancer incidence. Reports of the detection of SV40 DNA in a variety of cancers have raised serious concerns as to whether the inadvertent inoculation with SV40 has led to the development of cancer in humans. However, inconsistent reports linking SV40 with various tumor types has led to conflicting views regarding the potential of SV40 as a human cancer virus. Several recent studies suggest that older detection methodologies were flawed, and the limitations of these methods could account for most, if not all, of the positive correlations of SV40 in human tumors to date. Although many people may have been exposed to SV40 by polio vaccination, there is inadequate evidence to support widespread SV40 infection in the population, increased tumor incidence in those individuals who received contaminated vaccine, or a direct role for SV40 in human cancer.