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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
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
2011-06-07 11:00:18
date last changed
2017-06-18 04:39:31
@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},
  volume       = {40},
  year         = {2011},
}