Can the MMR Vaccine Cause SSPE?

The MMR vaccine can actually prevent SSPE!

Why do some people think that the MMR vaccine can cause SSPE?

The usual suspects...

Can the MMR Vaccine Cause SSPE?

In this case, though, they have some help from a couple of case reports that describe vaccinated children developing SSPE.

“This paper reports the case of a 15-year-old girl from India who developed SSPE presumably as a result of a delayed effect of measles, mumps, and rubella (MMR) vaccine.”

Measles, mumps, rubella vaccine induced subacute sclerosing panencephalitis

But these case reports are not good evidence…

“Subacute sclerosing panencephalitis (SSPE) is a slow-virus infection of the central nervous system associated with prior measles infection. Onset generally occurs in late childhood or adolescence and is usually characterized by the insidious onset of mental deterioration and myoclonia. Although spontaneous improvement or stabilization can occur, the vast majority of patients proceed over a period of months to years to generalized convulsions, dementia, coma, and death.”

Subacute Sclerosing Panencephalitis Surveillance -- United States

In general, we think of SSPE as a late complication of natural measles infections.

It occurs about 7 to 10 years after an acute measles infection, as the measles virus, long dormant, develops into a persistent infection in the brain.

“Reported SSPE cases with onset since 1973 have declined substantially paralleling the substantial decline in reported measles cases after 1964-1966.”

Subacute Sclerosing Panencephalitis Surveillance -- United States

That SSPE is only caused by natural measles infections is backed up by the very simple fact that cases of SSPE have dropped nearly in sync with the drop in measles cases that came with the introduction of routine measles vaccination!

As most folks hopefully know, the things in the Adverse Reactions section of the package insert are listed despite their not having an established causal relationship to the MMR vaccine.

And tragically, they go up anytime we see a surge in measles cases…

There is also the fact that despite a few case reports, “studies have shown that measles vaccine strains do not cause SSPE,” including:

1. a 2005 study, Subacute Sclerosing Panencephalitis: More Cases of This Fatal Disease Are Prevented by Measles Immunization than Was Previously Recognized, found that all of the cases, even those who had been previously vaccinated, had a wild type measles genotype, not a vaccine strain.

2. a 2002 study, Characterization of measles virus strains causing SSPE: a study of 11 cases, found that “No vaccine strains were detected although five of these patients had been previously immunized.”

3. a 2002 study, Molecular analysis of measles virus genome derived from SSPE and acute measles patients in Papua, New Guinea, found that “No genome sequences of vaccine strains were detected.”

4. a 2007 study, Review of the effect of measles vaccination on the epidemiology of SSPE, found 23 cases (worldwide) of SSPE with a history of vaccination, “but vaccine strain or genotype A was not identified in any of them. Instead, a wide range of virus genotypes have been identified, reflecting the diversity of wild-type genotypes.”

But what about the few case reports of vaccinated folks who develop SSPE?

You will notice that these are case reports that do not include genotype testing on the measles strain responsible for causing the person to develop SSPE!

Then how do you explain what happened to them?

Since they were vaccinated, they may have had a mild breakthrough measles infection and had not known it. And tragically, although their symptoms were mild at the time, the infection was still able to later trigger SSPE.

So no, the MMR vaccine does not cause SSPE!

It makes no sense to think that it does, after all, why wouldn’t we have more and more cases after the introduction of the MMR vaccine instead of a drop?

“Measles vaccine directly protects against SSPE by preventing measles infection and has the potential to eliminate SSPE through the elimination of measles.”

Review of the effect of measles vaccination on the epidemiology of SSPE

In fact, avoiding SSPE is one of the benefits of getting vaccinated!

References

Subacute Sclerosing Panencephalitis Surveillance -- United States. MMWR. November 05, 1982 / 31(43);585-8 https://www.cdc.gov/mmwr/preview/mmwrhtml/00001185.htm

William J. Bellini, Jennifer S. Rota, Luis E. Lowe, Russell S. Katz, Paul R. Dyken, Sherif R. Zaki, Wun-Ju Shieh, Paul A. Rota, Subacute Sclerosing Panencephalitis: More Cases of This Fatal Disease Are Prevented by Measles Immunization than Was Previously Recognized, The Journal of Infectious Diseases, Volume 192, Issue 10, 15 November 2005, Pages 1686–1693, https://doi.org/10.1086/497169

Liko J, Guzman-Cottrill JA, Cieslak PR. Notes from the Field: Subacute Sclerosing Panencephalitis Death — Oregon, 2015. MMWR Morb Mortal Wkly Rep 2016;65:10–11. DOI: http://dx.doi.org/10.15585/mmwr.mm6501a3

Jin L, Beard S, Hunjan R, Brown DW, Miller E. Characterization of measles virus strains causing SSPE: a study of 11 cases. J Neurovirol. 2002 Aug;8(4):335-44. doi: 10.1080/13550280290100752. PMID: 12161818.

Miki K, Komase K, Mgone CS, Kawanishi R, Iijima M, Mgone JM, Asuo PG, Alpers MP, Takasu T, Mizutani T. Molecular analysis of measles virus genome derived from SSPE and acute measles patients in Papua, New Guinea. J Med Virol. 2002 Sep;68(1):105-12. doi: 10.1002/jmv.10176. PMID: 12210437.

H Campbell, N Andrews, K E Brown, E Miller, Review of the effect of measles vaccination on the epidemiology of SSPE, International Journal of Epidemiology, Volume 36, Issue 6, December 2007, Pages 1334–1348, https://doi.org/10.1093/ije/dym207