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Smallpox vaccination and all-cause infectious disease hospitalization: a Danish register-based cohort study.

Sørup, Signe ; Villumsen, Marie ; Ravn, Henrik ; Benn, Christine Stabell ; Sørensen, Thorkild I A ; Aaby, Peter ; Jess, Tine and Roth, Adam LU (2011) In International Journal of Epidemiology 40. p.955-963
Abstract
BACKGROUND: There is growing evidence from observational studies and randomized trials in low-income countries that vaccinations have non-specific effects. Administration of live vaccines reduces overall child morbidity and mortality, presumably due to protection against non-targeted infections. In Denmark, the live vaccine against smallpox was phased out in the 1970s due to the eradication of smallpox. We used the phasing-out period to investigate the effect of smallpox vaccination on the risk of hospitalization for infections. METHODS: From the Copenhagen School Health Records Register, a cohort of 4048 individuals was sampled, of whom 3559 had information about receiving or not receiving smallpox vaccination. Infectious disease... (More)
BACKGROUND: There is growing evidence from observational studies and randomized trials in low-income countries that vaccinations have non-specific effects. Administration of live vaccines reduces overall child morbidity and mortality, presumably due to protection against non-targeted infections. In Denmark, the live vaccine against smallpox was phased out in the 1970s due to the eradication of smallpox. We used the phasing-out period to investigate the effect of smallpox vaccination on the risk of hospitalization for infections. METHODS: From the Copenhagen School Health Records Register, a cohort of 4048 individuals was sampled, of whom 3559 had information about receiving or not receiving smallpox vaccination. Infectious disease hospitalizations were identified in the Danish National Patient Register. RESULTS: During 87 228 person-years of follow-up, 1440 infectious disease hospitalizations occurred. Smallpox-vaccinated individuals had a reduced risk of all-cause infectious disease hospitalization compared with smallpox-unvaccinated individuals [hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.72-0.98]. The reduced risk of hospitalizations was seen for most subgroups of infectious diseases. The effect may have been most pronounced after early smallpox vaccination (vaccination age <3.5 years: HR 0.81; 95% CI 0.69-0.95; vaccination age ≥3.5 years: HR 0.91 95% CI 0.76-1.10). Among the smallpox-vaccinated, the risk of infectious disease hospitalization increased 6% with each 1-year increase in vaccination age (HR 1.06; 95% CI 1.02-1.10). CONCLUSION: Smallpox vaccination is associated with a reduced risk of infectious disease hospitalization in a high-income setting. (Less)
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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Epidemiology
volume
40
pages
955 - 963
publisher
Oxford University Press
external identifiers
  • wos:000294108700021
  • pmid:21543446
  • scopus:80051938730
ISSN
1464-3685
DOI
10.1093/ije/dyr063
language
English
LU publication?
yes
id
217e04a9-e314-4437-8f3c-1094b73b327b (old id 1973154)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/21543446?dopt=Abstract
date added to LUP
2016-04-04 08:12:39
date last changed
2022-04-07 23:34:58
@article{217e04a9-e314-4437-8f3c-1094b73b327b,
  abstract     = {{BACKGROUND: There is growing evidence from observational studies and randomized trials in low-income countries that vaccinations have non-specific effects. Administration of live vaccines reduces overall child morbidity and mortality, presumably due to protection against non-targeted infections. In Denmark, the live vaccine against smallpox was phased out in the 1970s due to the eradication of smallpox. We used the phasing-out period to investigate the effect of smallpox vaccination on the risk of hospitalization for infections. METHODS: From the Copenhagen School Health Records Register, a cohort of 4048 individuals was sampled, of whom 3559 had information about receiving or not receiving smallpox vaccination. Infectious disease hospitalizations were identified in the Danish National Patient Register. RESULTS: During 87 228 person-years of follow-up, 1440 infectious disease hospitalizations occurred. Smallpox-vaccinated individuals had a reduced risk of all-cause infectious disease hospitalization compared with smallpox-unvaccinated individuals [hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.72-0.98]. The reduced risk of hospitalizations was seen for most subgroups of infectious diseases. The effect may have been most pronounced after early smallpox vaccination (vaccination age &lt;3.5 years: HR 0.81; 95% CI 0.69-0.95; vaccination age ≥3.5 years: HR 0.91 95% CI 0.76-1.10). Among the smallpox-vaccinated, the risk of infectious disease hospitalization increased 6% with each 1-year increase in vaccination age (HR 1.06; 95% CI 1.02-1.10). CONCLUSION: Smallpox vaccination is associated with a reduced risk of infectious disease hospitalization in a high-income setting.}},
  author       = {{Sørup, Signe and Villumsen, Marie and Ravn, Henrik and Benn, Christine Stabell and Sørensen, Thorkild I A and Aaby, Peter and Jess, Tine and Roth, Adam}},
  issn         = {{1464-3685}},
  language     = {{eng}},
  pages        = {{955--963}},
  publisher    = {{Oxford University Press}},
  series       = {{International Journal of Epidemiology}},
  title        = {{Smallpox vaccination and all-cause infectious disease hospitalization: a Danish register-based cohort study.}},
  url          = {{http://dx.doi.org/10.1093/ije/dyr063}},
  doi          = {{10.1093/ije/dyr063}},
  volume       = {{40}},
  year         = {{2011}},
}