Intended for healthcare professionals

Editorials

Improving uptake of MMR vaccine

BMJ 2008; 336 doi: https://doi.org/10.1136/bmj.39503.508484.80 (Published 03 April 2008) Cite this as: BMJ 2008;336:729
  1. Peter McIntyre, director,
  2. Julie Leask, research fellow
  1. 1National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children’s Hospital at Westmead, NSW 2145, Australia
  1. PeterM{at}chw.edu.au

Recognising and targeting differences between population groups are the priorities

Almost a decade since the original report suggesting a link between the combined measles, mumps, and rubella (MMR) vaccine and autism or inflammatory bowel disease, we now have overwhelming evidence to refute such a link.1 Some people, however, still refuse to have their children vaccinated for MMR, and sometimes replace the combined vaccine with single antigen vaccines. In the accompanying study, Pearce and colleagues report uptake of the combined MMR vaccine and single antigen vaccines and they discuss the factors influencing uptake in a three year follow-up of the UK millennium cohort.2

Low MMR vaccine coverage is not a trivial matter, because the accumulation of unvaccinated children will increase the risk of measles outbreaks. Confirmed cases of measles in England and Wales rose from 56 in 1998 to 971 in 2007 (figure).3 In the United Kingdom, coverage for MMR at 24 months is lower than for other vaccines (85% versus about 94%).4 Such a wide gap between coverage for MMR and other vaccines has not been seen in other countries.What do data from the UK and elsewhere on the characteristics of parents who refuse vaccines and their sources of advice tell us about the best ways to tackle their concerns at the individual and population level?1 2

Figure1

MMR coverage at 24 months in the UK and laboratory confirmed cases of measles for all ages (England and Wales), 1995-20073 4

Pearce and colleagues report that parents in the millennium cohort who sought single antigen vaccines were significantly more likely to be white, well educated, affluent, older mothers, and to have just one child, compared with parents who fully immunised their child. In contrast, families whose children had not received MMR vaccine showed a less uniform pattern. They were more likely to have a larger family size and the mothers were more likely to smoke, be either younger or older than average, and have higher than average levels of education but not income. This may be because Pearce and colleagues did not differentiate between children lacking only MMR vaccine, those lacking some other vaccines, and those who had received no scheduled vaccines. This is probably important, because in the United States,5 Australia,6 and in this cohort at 9 months of age,7 non-selective partial immunisation is associated with indicators of disadvantage, in direct contrast to vaccine refusal by choice.

A recent UK study differentiated two groups of people who are suspicious about vaccination into “reformists,” who were critical of vaccines but likely to support vaccination in at least some respects, and “radicals,” who followed alternative notions of health and questioned all vaccines.8 Parents who seek out single antigen vaccines or those who selectively refuse MMR are more likely to fit the reformist definition, and may be receptive to approaches that deal with their concerns in an open and individualised way. Parents who refuse all vaccines are more likely to fit the radical definition. Even the best communication strategies are unlikely to change such people’s opinions.

What can be done to reach the 95% or greater coverage with MMR needed to eliminate measles? Attitudes are key, because 14% of UK mothers in 2006 considered MMR a greater risk than the diseases it prevents, although this proportion had decreased from a peak of 24% in 2002.9 At the individual level, efforts to persuade parents with deep seated philosophical or religious objections to all vaccines are likely to be futile. The main focus should be on parents of partially immunised children, who fall into two broad groups—those who are socially or materially advantaged and those who are not. Strategies to tackle late or partial immunisation (or both) in disadvantaged populations should focus on improving access. Families who selectively refuse MMR, usually on the basis of safety concerns,9 are likely to have almost 95% coverage for other vaccines.5 Communication needs to consider the experience and context of the individual families.10 Pilot work with a detailed MMR decision aid for parents found that it has potential for influencing attitudes and knowledge.11 The aid details rates of measles and its complications and adverse events related to MMR vaccination. This balance is useful because some parents in the UK think of official information as biased and want information that is seen as “independent.”1 9 At the population level, initiatives such as linking parental financial incentives or entry to school or childcare facilities to completion of immunisation have improved overall immunisation coverage but require legislative action and societal support.12

The goal of 95% immunisation coverage is a constant challenge, and the occurrence of disease outbreaks when coverage wanes is a salient reminder of the need for vigilance. Targeted strategies that recognise the different groups of people who contribute to low immunisation coverage are needed to achieve the best possible control of vaccine preventable diseases.

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References

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