MMR vaccine is a three part vaccine, given by injection, which is to protect (immunize) against Measles, Mumps and German Measles (Rubella).
The vaccine is a freeze-dried preparation which contains live virus particles of the three viruses, which have been modified (attenuated) to stop them from producing the full effects of the disease. The vaccine is given, by injection, into the thigh or upper arm. It has been found that a booster, before school, makes it likely that more people will be properly protected.
The idea is to fool the body’s defense system into thinking it is under attack by the viruses, and to produce defense mechanisms (antibodies) which will fight off the conditions if they are encountered in the future. There is no risk of someone who has been vaccinated infecting other people with the viruses.
Usually the vaccine is for children, but it can be given to non-immune adults. It is suggested that people in long term institutional care, who are not immune, should have the vaccine. It is also recommended that students starting at college or university, who have not received the vaccine previously, should be offered it.
Reasons for having the inoculation
The most serious of these, as far as how ill the child gets, is Measles, but all of them can have serious and even fatal complications. In the case of German Measles the major worry is that of risk to the unborn baby if caught by a woman during early pregnancy. Mumps too can have serious affects, and affect male fertility, when caught after puberty.
These conditions are still common on a world-wide basis. In countries like the UK, where the take-up rate of immunizations is high, the actual occurrence of the conditions becomes rare. It is not, however, possible to stop immunization, because of the high level of the conditions elsewhere in the world, and the volume of international travel.
It is true that the amount that a disease occurs (the incidence) will reduce once a certain percentage of the population has been inoculated. This is called “herd immunity”. It is possible for some individuals to depend on this and avoid having the vaccine themselves. This is, however, selfish and if everybody had that attitude, the diseases would remain widespread.
Anything we take into our body can have side effects. Medicines, and in this case MMR vaccine, are no exception, but vaccines are among the safest medicines.
The commonest side effects are similar to a mild version of one of the viruses involved, and not very different to the measles vaccine which was previously used. The child may be generally less vigorous, have a slight fever and possibly a rash, most often about a week after the immunization and lasting about two or three days. Swelling of the glands in the cheeks, as seen in mumps, may happen about three weeks after the injection in about 1 in 100 cases.
Occasionally more serious events, such as convulsions, occur. This happens in about 1 in 1000 cases, six to eleven days after the injection. If your child develops worrying side effects you should contact your doctor.
Other conditions where a link with MMR Vaccine has been suggested
Asthma has been linked, by some studies, with MMR vaccine, but the current view of the experts (epidemiologists) is that there is no strong evidence to support this.
Guillain-Barré Syndrome is a rare condition of the nervous system which causes acute paralysis. There is strong evidence that this is not brought about by by measles vaccination, which was a worry previously expressed by some people.
Crohn’s Disease is a chronic inflammatory disease of the bowels. Many factors have been linked to this illness. Some research has been published which suggests a possible link between measles vaccine and Crohn’s Disease.
The World Health Organization (WHO) has apparently rejected this work, as have many other experts in the field. Independent researchers have not been able to confirm the link, which is what the scientific community would expect in order to accept it.
Autism is a condition which leads to delayed speech and communication and intellectual impairment, which is usually diagnosed in the second year of life. Research in Sweden shows that the number of cases of Autism diagnosed did not rise after the introduction of the MMR vaccine.
Subacute Sclerosing Pan encephalitis
Subacute Sclerosing Pan encephalitis (SSPE) is a rare condition which causes degeneration of the nervous system some years after a natural infection with measles. It leads to brain damage and death. This is a rare complication of measles (1 in 8000 who catch it under two years old) and comes on after about eight years.
The evidence is that the number of people with SSPE has fallen dramatically since the introduction of measles vaccine in the UK in the 1960s, that is the measles component of the MMR vaccine directly protects against this terrible condition.
Allergy to eggs
If your child is strongly allergic to eggs you should mention it to your doctor. The administration of the vaccine (which has eggs involved in its production) has been proved to be safe, even in such cases, but your doctor may prefer the injection to be given as a day case at the hospital, if there is any doubt.
Weighing up the risks versus the benefits
Nothing in life is without risk, but here the balance, for most people, is in favor of having the MMR Vaccine. It not only protects the patient, but also unborn babies.
|Complications||Risk after natural disease||Risk after first dose of MMR|
|Fits (convulsions)||1 in 200||1 in 1000|
|Meningitis / encephalitis||1 in 200 to 1 in 5000||1 in 1000000|
|Conditions affecting the clotting of the blood||1 in 3000||1 in 24000|
|Severe allergic response (anaphylaxis)||–||1 in 100000|
|Deaths||1 in 8000 to 1 in 10000 (depends on age)||0|
Some children are at particular risk from a measles infection and should have the MMR vaccine (or measles vaccine in countries where only that is available). Children with:
- Cystic Fibrosis
- Congenital heart disease
- Kidney disease
- Downs syndrome
- Poor growth
Also children, from one year of age, who are in residential care or day care.