MMR vaccine (Measles-Mumps-Rubella)
The measles-mumps-rubella (MMR) vaccine is obtained from live but harmless viruses. It is administered subcutaneously.
When to vaccinate
The vaccination schedule includes two doses of MMR:
- the first dose between 12 and 15 months of age;
- the second dose at 5-6 years of age.
In particular situations, when more immediate protection is required, the second dose can be administered after a minimum of 28 days from the first one. Children from 6 to 12 months who have come into contact with a case of measles, or during an epidemic, can also be vaccinated, although in this case the dose is not counted and the first valid dose should still be administered after the age of 12 months. Adults who cannot prove either that they have been vaccinated or that they have contracted any of the diseases in the past should receive at least one dose of vaccine.
The vaccine can be given at the same time as any other vaccine.
A combined vaccine, MMRV, which contains both the MMR and the varicella vaccine can be administered in place of the two individual vaccines in children and twelve-year-olds.
Who should not be vaccinated
- Anyone who has had a severe allergic reaction to the first dose of the vaccine, to neomycin or to other components of the vaccine;
- Patients with rare hereditary problems of fructose intolerance (the MMR vaccine contains sorbitol);
- Vaccination of pregnant women should be postponed until after delivery. Women who have been vaccinated with MMR should avoid getting pregnant for 4 weeks after vaccination. However, the accidental vaccination of pregnant women is not be a reason for the interruption of pregnancy;
- The vaccinating doctor must be informed if the person receiving the vaccine:
- has a disease that affects the immune system (eg HIV/AIDS) or is being treated with drugs that suppress the immune system;
- has any type of cancer or is being treated for cancer;
- has a low platelet count (or other blood diseases);
- has received a vaccine in the last 4 weeks;
- has received immunoglobulins or a blood transfusion.
All of these conditions can require the vaccination to be postponed, or not carried out at all.
The vaccinated subject poses no risk for pregnant women and individuals with compromised immune systems: the possibility of a vaccinated person infecting other members of his family has never been documented.
Subjects with a mild to medium grade allergy to eggs may be vaccinated normally; subjects with a more severe allergy can still be vaccinated, taking certain precautions (consult your paediatrician).
When to postpone vaccination
Patients with mild illnesses can generally be safely vaccinated. If, on the other hand, they have moderate or severe illnesses, it is advisable to delay vaccination until they have recovered (in this case, it is always better to contact a paediatrician or family doctor).
- Ongoing antibiotic therapy;
- Pregnancy of a partner;
- Local reactions or mild fever after a previous vaccination;
- Personal or family history of convulsions and neurological diseases;
- Family history of SIDS (see There is no link between vaccines and cot death)
- Down syndrome
- Vaccination risks
Like any other drug, vaccines can cause serious problems, such as severe allergic reactions. The risk of the MMR vaccine causing serious damage or death is extremely low and is most certainly lower than the risks of complications for those who contract the diseases. Most people who receive the MMR vaccine do not encounter any serious problems. In addition to the common reactions (swelling, redness and pain) at the injection site, there may be:
- Fever (up to 1 in 6 cases);
- Mild exanthema (red spots on the body) 5%;
- Swelling of the face or behind the neck (about 1 in 75 cases) 1-2%.
These reactions occur 6-14 days after vaccination and are not frequent.
Moderate (rare) reactions
- 1/30,000 febrile seizures;
- Joint pain and inflammation (more frequent in adolescents or adults, especially women) 0.5% in children, 25% in predisposed adults (who would develop a more severe form if they were to contract the disease);
- Reduction in the number of platelets (thrombocytopenia) 1/30,000 within 2 months.
Serious reactions (extremely rare)
Some serious reactions, such as severe allergic reactions (less than 1 case per million doses), are reported after vaccination with the MMR vaccine. Other serious complications (deafness, protracted convulsions, coma, permanent brain damage) are so rare that it is difficult to associate them with the use of the vaccine.
Numerous studies have excluded any relationship between the MMR vaccine and autism (see Vaccines do not cause autism).