New study warns of potential epidemics in UK
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《英国医生杂志》
A new Canadian study suggests that Britain may face a high risk of epidemics in preventable diseases such as measles and whooping cough.
The study抯 authors, Chris Bauch and David Earn, analysed how the general public抯 perception of the risks associated with vaccines can influence vaccination uptake rates and disease outbreaks. They found that a parent抯 decision to vaccinate or not is influenced by their perception of the vaccine抯 risk, whether that risk is accurate or inflated (published online in the Proceedings of the National Academy of Sciences on 25 August, in PNAS 揺arly edition?(www.pnas.org).
The researchers investigated the substantial drop in vaccination rates in Britain for the measles, mumps, and rubella (MMR) vaccine after a 1998 report suggested a potential link between the MMR vaccine and autism.
The MMR vaccine scare in Britain was based essentially on a hunch, not on scientific evidence, said Dr Bauch, a professor of mathematics at the University of Guelph in Ontario.
Several scientific studies published since 1998 have failed to find any statistical link between the MMR vaccine and autism, pointed out Dr Bauch. However, he said, various surveys have found that parents in the United Kingdom continue to believe that the MMR vaccine carries more risk than the diseases against which it protects. 揑f this trend continues, measles epidemics in Great Britain are inevitable,?he predicted.
Dr Bauch and Dr Earn have developed a mathematical model that provides a population-level perspective on vaccine scares and which predicts to what extent vaccination rates for preventable diseases drop after a vaccine scare. Vaccine scares are often followed by educational campaigns aimed at increasing public confidence, but the researchers explain mathematically how the effectiveness of such programmes is constrained.
Their model shows how it is relatively easy for a health scare to affect vaccine uptake rates. Even if use of the perceived vaccine is greatly reduced, however, it is relatively difficult to restore vaccine coverage to the levels that existed before a scare. The researchers also found that increases in perceived vaccine risk will tend to induce larger declines in vaccine uptake for pathogens that cause more secondary infections (such as measles and pertussis).
揗y research hypothesises a population-level context of vaccine scares that is important and should not be ignored,?Dr Bauch told the BMJ. 揟he decisions made by parents are indirectly influenced by what other parents decide, because these decisions collectively determine vaccine uptake, and hence the risk of outbreaks, and hence the risk of infection to individual children.?
In situations where vaccine coverage is very high, a few parents can opt not to have their children vaccinated. This is because they gain the benefits of 揾erd immunity?without experiencing the perceived risks of the MMR vaccine, he explained. However, he said, when this behaviour spreads, and more parents stop having their children vaccinated, the population eventually reaches a 搕ipping point?at which large epidemics become possible.(Ontario Barbara Kermode-S)
The study抯 authors, Chris Bauch and David Earn, analysed how the general public抯 perception of the risks associated with vaccines can influence vaccination uptake rates and disease outbreaks. They found that a parent抯 decision to vaccinate or not is influenced by their perception of the vaccine抯 risk, whether that risk is accurate or inflated (published online in the Proceedings of the National Academy of Sciences on 25 August, in PNAS 揺arly edition?(www.pnas.org).
The researchers investigated the substantial drop in vaccination rates in Britain for the measles, mumps, and rubella (MMR) vaccine after a 1998 report suggested a potential link between the MMR vaccine and autism.
The MMR vaccine scare in Britain was based essentially on a hunch, not on scientific evidence, said Dr Bauch, a professor of mathematics at the University of Guelph in Ontario.
Several scientific studies published since 1998 have failed to find any statistical link between the MMR vaccine and autism, pointed out Dr Bauch. However, he said, various surveys have found that parents in the United Kingdom continue to believe that the MMR vaccine carries more risk than the diseases against which it protects. 揑f this trend continues, measles epidemics in Great Britain are inevitable,?he predicted.
Dr Bauch and Dr Earn have developed a mathematical model that provides a population-level perspective on vaccine scares and which predicts to what extent vaccination rates for preventable diseases drop after a vaccine scare. Vaccine scares are often followed by educational campaigns aimed at increasing public confidence, but the researchers explain mathematically how the effectiveness of such programmes is constrained.
Their model shows how it is relatively easy for a health scare to affect vaccine uptake rates. Even if use of the perceived vaccine is greatly reduced, however, it is relatively difficult to restore vaccine coverage to the levels that existed before a scare. The researchers also found that increases in perceived vaccine risk will tend to induce larger declines in vaccine uptake for pathogens that cause more secondary infections (such as measles and pertussis).
揗y research hypothesises a population-level context of vaccine scares that is important and should not be ignored,?Dr Bauch told the BMJ. 揟he decisions made by parents are indirectly influenced by what other parents decide, because these decisions collectively determine vaccine uptake, and hence the risk of outbreaks, and hence the risk of infection to individual children.?
In situations where vaccine coverage is very high, a few parents can opt not to have their children vaccinated. This is because they gain the benefits of 揾erd immunity?without experiencing the perceived risks of the MMR vaccine, he explained. However, he said, when this behaviour spreads, and more parents stop having their children vaccinated, the population eventually reaches a 搕ipping point?at which large epidemics become possible.(Ontario Barbara Kermode-S)