Measles is not the “number one side effect” of the MMR vaccine

Published: 23rd May 2019

In brief

Claim

According to the vaccine manufacturer’s own vaccine package insert, measles is the number one side effect of the MMR.

Conclusion

Incorrect. “Atypical measles” is mentioned as an adverse reaction (which is not the same as a side effect) of the MMR vaccine used in the US and one of the UK MMR vaccines. People given a certain type of measles jab in the 1960s and 70s could get “atypical measles” if they were exposed to a certain measles strain afterwards. The other UK MMR vaccine brand lists “atypical measles” as a “possible side effect” as some people who were given the MMR got atypical measles if they also got the old measles jab.

 

Pancreatitis, Diabetes Mellitus (Type 2), anaphylaxis, arthritis, encephalitis, aseptic meningitis, pneumonia, deafness, retinitis and epididymitis are also listed as side effects.

 

Incorrect. All of these (except aseptic meningitis) are listed under “adverse reactions” of the MMR II vaccine used in the US. That’s not the same as a side effect. Adverse reactions can refer to anything developed by chance after someone is vaccinated, but these aren’t necessarily caused by the vaccine. The two UK MMR vaccines list some of these as adverse reactions.

 

Death is listed as a side effect of the MMR vaccine.

 

Incorrect. The US MMR vaccine package insert, under “adverse reactions”, says death from various and sometimes unknown causes has been reported after vaccination but a causal relationship hasn’t been found in healthy individuals. Death isn’t listed under adverse reactions on either MMR vaccine used in the UK.

 

Measles is at the top of the list of the MMR vaccine’s adverse reactions.

 

Atypical measles is listed as one of the “adverse reactions” of the MMR vaccine used in the US and one of the UK brands (it is not “top” of these lists). That’s because people vaccinated with a certain brand of measles jab in the 60s and 70s were still able to get “atypical measles” if they were exposed to a certain measles strain. The other UK brand lists “atypical measles” as a “possible side effect” as some people who were given that MMR vaccine got atypical measles if they also got the old measles jab.

Claim 1 of 4

A post with over 1,500 shares on Facebook has made several claims about the MMR vaccine, including that measles is listed as its number one side effect, and that there are a number of other serious side effects, including death.

The MMR vaccine used in the US does list measles and most of the diseases mentioned in the post as “adverse reactions”, but these are not the same as side effects.

Adverse reactions are conditions which may have occurred after someone got the vaccine but weren’t necessarily caused by it. The two MMR vaccines used in the UK list some of the diseases mentioned by the Facebook post as adverse reactions or side effects. None of these vaccines say death is a side effect.

Measles is not listed as the number one side effect of the MMR vaccine

The two MMR vaccines used in the UK are MMRVaxPRO and Priorix.

MMRVaxPro lists “atypical measles” as a “possible side effect” of unknown frequency in its information leaflet for doctors, but says atypical measles is “described in patients who received a killed measles virus vaccine, usually given before 1975”. That means that atypical measles was observed in a small number of patients who got MMRVaxPro and had previously received killed version of the measles vaccine containing an inactivated version of the virus in it.

“Atypical measles” is a form of measles usually seen in people who got a specific type of measles vaccine in the 1960s or 1970s. That vaccine did not protect against measles, and people who got the vaccine sometimes developed atypical measles if they were subsequently infected with a certain strain of measles.

The Priorix package insert lists “atypical mild or attenuated measles” as an adverse reaction.

The MMR vaccine brand used in the US, called MMR II, also lists atypical measles as an “adverse reaction”, not a side effect.

Adverse reactions are not the same as side effects

We’ve talked before about how adverse reactions on a vaccine package insert aren’t the same as side effects.

The adverse reactions listed on a vaccine’s package insert can include anything that happened after a vaccination, but was not necessarily caused by it. Adverse reactions are not side effects of the vaccine itself.

The Vaccine Knowledge Project at the University of Oxford says “when a vaccine is given to a very large number of people in a population, it is likely just by chance that a few of them will develop some kind of medical problem around the time of vaccination, but this does not prove ‘cause and effect’.”

Some of the other conditions mentioned in the Facebook post are also listed as adverse reactions in the package inserts of the MMR vaccines used in both the UK and US.

Pancreatitis, diabetes mellitus (the name for type 1 or type 2 diabetes), anaphylaxis, arthritis, encephalitis, pneumonia, deafness, retinitis (a range of inherited eye conditions) and epididymitis are all listed as adverse reactions on the US brand of the MMR vaccine, called MMR II.

Aseptic meningitis (another one of the conditions mentioned by the Facebook post) is not listed as an adverse reaction of MMR II. The package insert says: “cases of aseptic meningitis have been reported…following measles, mumps, and rubella vaccination” but it also adds that a causal relationship has only been shown between the disease and a different type of mumps vaccine, and not the one used in MMR II.

The Facebook post also claims death is listed on the vaccine’s package insert as a side effect. The MMR II insert says under adverse reactions: “Death from various, and in some cases unknown, causes has been reported rarely following vaccination with measles, mumps, and rubella vaccines; however, a causal relationship has not been established in healthy individuals…

“No deaths or permanent sequelae were reported in a published post-marketing surveillance study in Finland involving 1.5 million children and adults who were vaccinated with M-M-R II during 1982 to 1993.”

So death is not listed as a separate side effect.

Pancreatitis, diabetes, and death are not listed as side effects or adverse reactions in the package inserts for the UK’s MMR vaccines.

MMRVaxPro’s package insert does list aseptic meningitis, pneumonia, deafness, and retinitis, as adverse reactions. Priorix mentions meningitis as an adverse reaction.

The package inserts for both UK vaccines mention arthritis, anaphylaxis encephalitis and epididymitis as adverse reactions.

This article is part of our work factchecking potentially false pictures, videos and stories on Facebook. You can read more about this—and find out how to report Facebook content—here. For the purposes of that scheme, we’ve rated this claim as false because the claim that death is listed as a side effect is incorrect for both the UK and US MMR vaccines, the claim that measles is the number one side effect is incorrect and the claim that lists a number of diseases as side effects is incorrect (if listed, they are adverse reactions).


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