BACKGROUND: Early poliovirus vaccines were accidentally contaminated with simian virus 40 (SV40). In Denmark, poliovirus vaccine was administered to most children from 1955 through 1961. SV40 DNA sequences have been detected in several human malignancies, including mesothelioma, ependymoma, choroid plexus tumors, and non-Hodgkin's lymphoma. To clarify whether SV40 infection increases risk of these cancers or of cancers arising in children, we examined cancer incidence in three Danish birth cohorts. METHODS: Population-based cancer incidence data from 1943 through 1997 were obtained from the Danish Cancer Registry. The relationship between exposure to SV40-contaminated vaccine and cancer incidence was evaluated by examining incidence in birth cohorts that differed in exposure to SV40-contaminated vaccine. In addition, cancer incidence was examined in children who were 0-4 years of age before, during, and after the period of vaccine contamination. Incidence was compared using Poisson regression, adjusting for age differences. All statistical tests were two-sided. RESULTS: After 69.5 million person-years of follow-up, individuals exposed to SV40-contaminated poliovirus vaccine as infants (i.e., born 1955-1961) or children (i.e., born 1946-1952) had lower overall cancer risk (age-adjusted relative risk [RR] = 0.86, 95% confidence interval [CI] = 0.81 to 0.91 and RR = 0.79, 95% CI = 0.75 to 0.84, respectively; P
Comment In: J Natl Cancer Inst. 2003 Aug 20;95(16):1249; author reply 125012928352
Comment In: J Natl Cancer Inst. 2003 Oct 15;95(20):1552-3; author reply 1553-514559879
In low-income countries, live measles vaccine reduces mortality from causes other than measles infection. Such nonspecific effects of vaccines might also be important for the health of children in high-income settings.
To examine whether the live vaccine against measles, mumps, and rubella (MMR) is associated with lower rates of hospital admissions for infections among children in Denmark.
Population-based cohort study of Danish children born 1997-2006 and followed up from ages 11 months to 2 years (last follow-up, August 31, 2008). Nationwide Danish registers provided data on vaccinations and hospital admissions. The recommended vaccination schedule was inactivated vaccine against diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) administered at ages 3, 5, and 12 months and MMR at age 15 months.
Incidence rate ratios (IRRs) of hospital admissions for any infection, comparing receipt of MMR vs DTaP-IPV-Hib as the most recent vaccine. Risks, risk difference, and number needed to vaccinate were calculated for receiving MMR on time.
The study included 495,987 children contributing with 56,889 hospital admissions for any type of infection during 509,427 person-years (rate, 11.2 per 100 person-years). For the 456,043 children who followed the recommended schedule and received MMR after the third dose of DTaP-IPV-Hib, MMR (rate, 8.9 per 100 person-years) vs the third dose of DTaP-IPV-Hib (rate, 12.4 per 100 person-years) as the most recent vaccine was associated with an adjusted IRR of 0.86 (95% CI, 0.84-0.88) for any admission for infection. There were 19,219 children immunized out of sequence. The adjusted IRR was 0.87 (95% CI, 0.80-0.95) for those receiving MMR (rate, 9.9 per 100 person-years) after the second dose of DTaP-IPV-Hib (rate, 15.1 per 100 person-years). However, in the 1981 children who subsequently received the third dose of DTaP-IPV-Hib (rate, 12.8 per 100 person-years) after MMR, the IRR for hospital admissions for infection was significantly greater (adjusted IRR, 1.62 [95% CI, 1.28-2.05]). The risk of admission for an infection between ages 16 months and 24 months was 4.6% (95% CI, 4.5%-4.7%) for receiving MMR on time and 5.1% (95% CI, 5.0%-5.2%) for not receiving MMR on time. The risk difference was 0.5 percentage point (95% CI, 0.4-0.6), and the number needed to vaccinate with MMR before age 16 months to prevent 1 admission for any infection was 201 (95% CI, 159-272).
In a cohort of Danish children, receipt of live MMR vs inactivated DTaP-IPV-Hib as the most recent vaccine was associated with a lower rate of hospital admissions for any infections. These findings require replication in other high-income populations.
Comment In: JAMA. 2014 Feb 26;311(8):804-524570243
Department of Economic History, Lund University, Sweden; Centre for Economic Demography, Lund University, Sweden; Max Planck Institute for Demographic Research, Germany. Electronic address: email@example.com.
This study explores the impact an exogenous improvement in childhood health has on later-life outcomes. Using extensive and detailed register data from the Swedish Interdisciplinary Panel covering up to 2011, we follow individuals exposed to the introduction of the first vaccine against polio in Sweden (birth cohorts 1937-1966) until adulthood in order to quantify the causal effect of polio vaccination on long-term economic outcomes. The results show that, contrary to what has been found in the literature for other health-related interventions, including other vaccines, exposure to the vaccine against polio did not seem to have any long-term effects on the studied adult economic outcomes. Upon closer inspection of how the disease affects children, this might be explained by the fact that no scarring effects from exposure to high incidence of polio were found on adult income, educational achievement, or hospitalizations, which seems to suggest that those who contracted the illness but suffered only the milder symptoms of the disease made a full recovery and had no lifelong sequels as a consequence of the condition. The absence of scarring effects is hypothesized to be related to the pathology and epidemiology of the disease itself, which infects many, but scars only those who suffer the most recognizable paralytic symptoms.
BACKGROUND: A study comparing diphtheria immunity in Norwegian and Russian schoolchildren indicated low immunity against diphtheria in Norwegian children before the booster dose given at age 11 years. The pertussis epidemic in Norway 1997-98 demonstrated decreasing vaccine immunity from age 5-6 years. The possibility of improving immunity against both diseases by a booster dose during early school age is therefore under consideration. MATERIAL AND METHODS: Immune response and adverse events were studied after a combined vaccine against diphtheria, tetanus, pertussis (acellular) and poliomyelitis (DTPa-IPV) given at seven years of age, and a combined vaccine against diphtheria, tetanus and pertussis (acellular) (DTPa) at 11 years of age, in two parallel trials including 124 and 83 participants respectively. RESULTS: The trials confirmed that the diphtheria immunity is lower than it ideally should be in more than 40% of children before the booster dose at age 11. Pertussis immunity is difficult to assess because there is no clear relationship between antibody levels and protection. All study participants responded well to all vaccine components. The 11-year-old children reported higher occurrence of adverse events than the 7-year-olds. All adverse events were brief and none were serious. INTERPRETATION: The results indicate that a booster dose of DTPa-IPV in early school age would give better protection against diphtheria and pertussis in Norwegian schoolchildren, without unacceptable side effects.