Measles, mumps, rubella (MMR): use of combined vaccine instead of single vaccines

Published 1 January 2014

1. Background

MMR vaccine uptake is still recovering from the low level it fell to in 1997 in the UK, following media coverage that the MMR vaccine might be linked with autism and Crohn’s disease.

Vaccine uptake among 2 year olds declined to around 80% in 2003 and 2004. This compares to around 92% in 1995 before the adverse publicity. The World Health Organization (WHO) recommends immunity levels of around 95% to prevent outbreaks of disease.

The link to autism and Crohn’s disease was pure speculation but the effects of the drop in uptake of MMR vaccine are still being felt today. Some parents are still not getting their children vaccinated - large numbers of children in the UK are unprotected, making epidemics possible, like the outbreaks in England and Wales that occurred in 2012 to 2013. These mainly affected 10 to 16 year olds who had missed out on vaccination in the late 1990s to early 2000, when vaccine uptake was low because of the negative publicity around MMR vaccine.

The possible links to autism and Crohn’s disease were investigated by Public Health England (now UK Health Security Agency), and have been proved wrong.

The MMR vaccine remains the most effective and safest way of protecting children against these dangerous diseases. We urge parents to make sure their children have the MMR vaccine.

1.1 MMR myths

One of the myths circulating in the press was that the vaccine had been inadequately tested for safety. This information was wrong; there’s extensive high quality information to back up the safety of MMR.

2. Single vaccines compared to combined MMR

With single vaccines, children would need 6 separate injections:

  • 3 primary doses - 1 measles, 1 mumps, 1 rubella
  • 3 pre-school boosters

Each injection can be uncomfortable and the act of immunisation is sometimes distressing for children.

2.1 No evidence for single vaccines

Using single vaccines for the diseases would be experimental. It’s unclear how long a gap to leave between each vaccine, as there’s no evidence on giving the vaccines separately.

No country recommends vaccination with the 3 separate vaccines. Some single vaccines are available in other European countries, where they may be used in special circumstances. For example, in France measles vaccine is used for nursery school children aged 9 to 12 months. These children usually have the MMR vaccine 6 months later.

2.2 Delayed protection by single vaccines

Single vaccines are less safe than MMR because they leave children vulnerable to dangerous diseases for longer. Giving 3 separate doses at spaced out intervals would mean that, after the first injection, the child still has no immunity to the other 2 diseases.

With the combined MMR most children are given good protection by a single dose given at about 12-15 months and protection is virtually complete by dose 2, a pre-school booster to catch children whose first dose didn’t stimulate a full immune response.

Delaying immunisations by splitting them has a similar effect to reducing the proportion of children immunised. More children are unprotected, increasing the risk to themselves and to other children.

In the past, when measles and rubella vaccines were used separately, children continued to get measles and babies were born with congenital rubella. When MMR was introduced, measles and congenital rubella were virtually eliminated

2.3 Decreased uptake

All the evidence suggests that uptake is poorer with single vaccines than with the combined MMR. With single vaccines fewer children would be protected. With 6 injections it’s likely that many children would not complete the course.

Some people argue that making single vaccines available would improve uptake because parents who refuse the MMR would take the single vaccines.

In fact, the evidence from the UK and elsewhere is that the opposite is true. One of the most striking features of the replacement of single measles vaccine with MMR in 1988 in this country is the significant improvement in vaccination uptake that followed.

2.4 Potency and toxicity

Single vaccines imported into this country haven’t been independently tested for potency and toxicity. We have evidence that some of the single vaccines are less effective or less safe than MMR.

Unlike MMR, where the evidence shows no link, no study has been conducted to look at single vaccines and either autism or bowel disease. In fact, there’s no reason to think that single vaccines would be less likely to cause autism or bowel disease than MMR.

Parents are asking for single vaccines as they’re scared by the unfounded stories they’ve heard and read about MMR, not because there is any evidence that single vaccines are any safer.

2.5 Increased rate of serious infections

If children don’t have protection against all 3 of these diseases, we run the risk of the resurgence of the infections. Not just measles outbreaks, but also the return of babies born with disabilities due to congenital rubella syndrome. And children can become deaf following mumps.

3. MMR vaccine used worldwide

MMR is the vaccine of choice in more than 100 countries worldwide. An extensive national and international network of specialists provide advice based on decades of experience of running a highly successful national vaccination programme. The programme has eradicated smallpox and brought many other diseases, including polio, diphtheria, whooping cough, and meningitis, under control.

The UK’s health professionals have a responsibility and mission to protect children’s health. They include NHS and UK Health Security Agency, public health doctors and nurses, paediatricians, immunologists and our professional bodies such as the Royal College of General Practitioners and the World Health Organization.

What we don’t want to see in the UK is a similar situation to the whooping cough vaccine scare story of the 1970s, when single whooping cough vaccines were offered to parents, and vaccination uptake fell to 30%.

Large epidemics of whooping cough resulted, with over 100,000 cases notified, and it took 15 years for coverage to improve enough to control whooping cough again. No one in public health wants to repeat this experience with measles.

Having reviewed the evidence, all professional bodies support MMR as the safest way to protect children and recommending single vaccines runs counter to this available evidence.

4. Why can’t parents choose?

Parents are free to choose whether to protect their children, as no vaccination is compulsory in the UK. The majority follow the good advice of their health visitor, practice nurse or GP and protect their children with MMR.

The NHS has a responsibility to offer the best available protection, which is MMR. Some parents, such as all of those with children too young to be vaccinated or with health problems such as leukaemia (who cannot be given live vaccines), have no choice; their child can only be protected if vaccination uptake is high in all other children.

5. If parents go ahead with single vaccines

If parents do get single vaccines from clinics, they must ask:

  • exactly which vaccine they’re being offered
  • when and where that vaccine was tested
  • what the results of those tests were - the safety, potency and purity of the vaccine
  • what post-vaccination follow-up their child will get

6. Conclusion

There’s no reason to make single vaccines available and every reason not to. Exhaustive research has provided very strong evidence that MMR is not linked to conditions like autism.

There is much evidence of:

  • the benefit of MMR in preventing disease
  • the drawbacks of single vaccines
  • the very serious consequences of the diseases themselves

Introducing single vaccines would go against all the evidence. It would probably further undermine public confidence in vaccines.

It’s important that we remind people about the dangers of the diseases we are trying to prevent, about the strong evidence for the safety and effectiveness of MMR vaccine, and about the importance of having their child vaccinated with MMR.

Offering single vaccines to parents when all the evidence indicates that this is likely to put children in the UK at risk runs counter to all recent initiatives to make NHS practice evidence-based.

Further information is available on NHS Choices’ MMR immunisation pages.