Combined MMR vaccine in childhood – measles

This fact box will help you to weigh the benefits and harms of the combined vaccine against measles, mumps and rubella (MMR). The focus of this fact box is on measles. The information and numbers are based on the best scientific evidence currently available.

This fact box was developed by the Harding Center for Risk Literacy.

What is measles?

Measles is a highly contagious viral infection. In the first phase, symptoms may include fever, coughing, rhinitis, conjunctivitis (pinkeye), and small white spots inside the mouth. In the second phase, a characteristic red blotchy rash develops. Even brief direct contact with contagious secretions from the throat or the nose (by touching contaminated objects) leads to an infection with the virus, which can also be spread through airborne droplets when infected people cough, sneeze, or speak [4].

What is a combined MMR vaccine?

The vaccination against measles is usually administered as a combined vaccine against measles, mumps, and rubella – hence the abbreviation MMR [4].

Who might consider the combined MMR vaccine?

Infants aged 11 to 14 months receive the first dose of the combination vaccine as part of their basic immunization series. The second vaccination, generally scheduled for children aged 15 to 23 months, is a precautionary measure in case the first vaccination did not lead to the development of immunity. Furthermore, all adults born after 1970 who have not been vaccinated, who have been vaccinated just once, or whose vaccination status is unknown may consider having a one-off combined MMR vaccination [4].

Fact box combined MMR vaccine in childhood – measles
Fact box combined MMR vaccine in childhood – measles © Harding Center for Risk Literacy
What does the fact box show?

The fact box shows the benefits and harms of combined MMR vaccine for people without vaccination in their childhood compared to people with vaccination in case of exposure to the measles virus.

The table may be read as follows:

If 10,000 people who had not been vaccinated against measles were exposed to the virus, 9,310 of them would be expected to contract measles. In contrast, 93 to 745 of 10,000 vaccinated people would contract measles after exposure to the virus.

If 10,000 people who had been vaccinated neither as a child nor as an adult were exposed to the measles virus, 9,124 of them would be expected to suffer from fever due to measles. Of 10,000 vaccinated people, between 91 and 730 would suffer from fever due to measles after exposure to the virus.

The numbers in the fact box are rounded. For the benefits, the numbers are based on model calculations. These calculate the probabilities of infections, symptomatic diseases, and frequencies of symptoms taking into consideration the effectiveness of the vaccine.

What other aspects should be considered?

If 10,000 people who had not been vaccinated against measles, whether as a child or an adult, came into contact with the measles virus, 93 to 559 of them would suffer from pneumonia due to measles. In contrast, 1 to 45 of 10,000 vaccinated people would suffer from pneumonia due to measles.

There is no connection between the MMR vaccine and autism. The study claiming this link published in 1998 has been proven a fake.

Allergic reactions to the MMR vaccine are very rare. Children with a severe allergy to eggs should be closely monitored after vaccination.

The fact box contains model calculations of the possible benefits and harms that can be expected after exposure to the measles virus. The frequency of exposure to the virus depends on many factors, such as the opportunities for the rubella virus to spread and the proportion of vaccinated people. Widespread vaccination additionally provides protection for people who normally cannot be vaccinated (herd immunity). This population, which includes people with weakened immune systems and pregnant women, benefits from the slower spread of the virus. Therefore, the World Health Organization (WHO) aims at a global vaccination rate of 95 out of every 100 children. It should be considered that a complete immunization series requires two doses of the vaccine.

The combined MMR vaccine protects against mumps and rubella as well. The vaccine is also available in combination with chickenpox (varicella-zoster virus) as a MMR+V vaccine. An individual vaccine against measles is hardly available anymore [4].

Do the results provide proof (evidence) for the benefits and harms of the vaccination?

Overall the evidence is of moderate quality. On the one hand, the contagion indices (proportion of those exposed to the rubella virus who become infected) and manifestation indices (proportion of those infected by the rubella virus who are symptomatic) have not been researched with adequate randomized controlled trials. On the other hand, the degree of effectiveness of the vaccine has been validated across various populations with different study designs. Thus, there is at least evidence that symptoms of measles are reduced among vaccinated people versus unvaccinated people.

Version history of the fact box
  • April 2016 (last update)
Sources

Information within the fact box was obtained from the following sources:

Data based on clinical practice are missing, e.g. information from textbooks and physicians on the prevalence (frequency) of the infection, the contagion and manifestation indices, and current patient studies.

Data based on clinical practice only partly correspond to the current vaccines and to the current health conditions of the German and Swiss populations [1-6].

The data on febrile seizure are based on two cohort studies with, respectively, 456,000 and 537,000 children aged 12 to 23 months. The vaccine contained the “Jeryl-Linn” strain of the virus.

The data on low platelet counts (thrombocytopenia) are based on a patient control study with 139 children aged 13 to 24 months.

[1] Demicheli V, Rivetti A, Debalini MG et al. Vaccines for measles, mumps and rubella in children. Cochrane Database Syst Rev 2012;2:CD004407.

[2] Doerr HW, Gerlich WH. Medizinische Virologie: Grundlagen, Diagnostik, Prävention und Therapie viraler Erkrankungen. Georg Thieme 2010.

[3] Plotkin S, Orenstein W, Offit P. Vaccines. 6 ed: Saunders 2012.

[4] Robert Koch-Institut. RKI-Ratgeber für Ärzte: Mumps. 2013; www.rki.de/DE/Content/Infekt/

EpidBull/Merkblaetter/Ratgeber_Mumps.html, Access date 22 Aug 2016.

[2] Doerr HW, Gerlich WH. Medizinische Virologie: Grundlagen, Diagnostik, Prävention und Therapie viraler Erkrankungen. Georg Thieme 2010.

[3] Plotkin S, Orenstein W, Offit P. Vaccines. 6 ed: Saunders 2012.

[4] Robert Koch-Institut. RKI-Ratgeber für Ärzte: Mumps. 2013; www.rki.de/DE/Content/Infekt/

EpidBull/Merkblaetter/Ratgeber_Mumps.html, Access date 22 Aug 2016.

[5] Bundeszentrale für gesundheitliche Aufklärung. Impfen-Info 2015; www.impfen-info.de, Access date 22 Aug 2016.

[6] Friese K, Mylonas I, Schulze A (eds.). Infektionserkrankungen der Schwangeren und des Neugeborenen. Springer 2013.

[7] Quast U, Stück B. Deutsches Grünes Kreuz (ed.). Ärzte Merkblatt 2002.[2] Doerr HW, Gerlich WH. Medizinische Virologie: Grundlagen, Diagnostik, Prävention und Therapie viraler Erkrankungen. Georg Thieme 2010.

[3] Plotkin S, Orenstein W, Offit P. Vaccines. 6 ed: Saunders 2012.

[7] Quast U, Stück B. Deutsches Grünes Kreuz (ed.). Ärzte Merkblatt 2002.

[1] Demicheli V, Rivetti A, Debalini MG et al. Vaccines for measles, mumps and rubella in children. Cochrane Database Syst Rev2012;2:CD004407.

[8] Black C, Kaye JA, Jick H. MMR vaccine and idiopathic thrombocytopaenic purpura. BJCP 2003;55(1):107-11.

[9] Patja A, Mäkinen-Kiljunen S, Davidkin I, et al. Allergic reactions to measles-mumps-rubella vaccination. Pediatrics 2001;107(2):e27.

[10] Vestergaard M, Hviid A, Madsen KM et al. MMR vaccination and febrile seizures: evaluation of susceptible subgroups and long-term prognosis. JAMA 2004;292(3):351-7.

[11] Wilson K, Hawken S, Kwong JC et al. Adverse events following 12 and 18 month vaccinations: a population-based, self-controlled case series analysis. PLoS One 2011;6(12):e27897.