SmartVax Discussion on the MMR vaccine

Measles is a highly-contagious viral infection, spread via aerosol transmission or fluids from nose or mouth, which results in a rash and high fever.  Most recover without complications, but measles can cause encephalopathy, blindness, deafness, pneumonia, and death (see Merck MMR description).  In the decade before measles vaccination began, an estimated 3M-4M people in the USA were infected each year, of whom 400-500 died (1 in 6,000 to 1 in 10,000 risk of death), 48,000 were hospitalized, and another 1,000 developed chronic disability from measles encephalitis [per CDC].

Mumps is a viral disease, spread by airborne droplets, that causes painful swelling of the salivary glands.  Testicular swelling and rash may also occur. The symptoms are generally not severe in children, but can in rare cases cause infertility in teenage males when going through puberty (see Disease Risk – Mumps).

Rubella (often called “German measles”) is a viral disease, spread by airborne droplets, that causes symptoms similar to the flu along with a rash.  The disease is often mild and attacks often pass unnoticed. The disease can last one to three days. Infection of a pregnant mother by rubella virus during pregnancy can be serious.  If the mother is infected within the first 20 weeks of pregnancy, the child may be spontaneously aborted or may be born with congenital rubella syndrome, which entails a range of serious incurable illnesses (see Disease Risk – Rubella).

The MMR (Measles-Mumps-Rubella) vaccine contains live attenuated (weakened) measles virus, mumps virus, and rubella virus.  The mercury-based thimerosal preservative is not used because it would kill the live viruses and make the vaccine ineffective.  Because it contains live measles virus, the vaccine can in rare cases cause measles-induced encephalopathy (brain damage).  The MMRV (Measles-Mumps-Rubella-Varicella) vaccine includes live attenuated varicella (chicken pox) virus.

There are concerns about adverse interaction when different live viruses are combined in one vaccine.  Merck’s ProQuad MMRV vaccine was approved in 2005 but in 2008, because of a twice-as-high risk of fever-related convulsions, the CDC dropped its preferential recommendation for this four-in-one vaccine (see ProQuad).  A new formulation of MMR was introduced that quadrupled the number of mumps viruses in 1990, a time near the start of the autism epidemic (see Change in MMR).

A 1998 MMR case-series study on 12 children by Dr. Andrew Wakefield found evidence that the MMR vaccine may be causing a persistent measles infection in the gastrointestinal tract of children, and hypothesized that this infection may be linked to the children’s autism.  There has been much recent press about how Dr. Wakefield has been discredited, and how the study has been retracted by the scientific journal where it was originally published.  If one accepts that the study has been discredited, it only means that one specific theory of how the MMR vaccine might cause autism has been eliminated.

Note: Wakefield and colleagues were the first to find that gastrointestinal abnormalities are common in autism, an important finding that has been replicated by research in five countries.  There is much more to the Wakefield story than has been shared widely in the press; for details, see Who is Dr. Andrew Wakefield? by Mary Holland, JD (an online chapter of the book “Vaccine Epidemic”) or read the book Callous Disregard by Dr. Wakefield.

Mumps and rubella don’t carry a significant risk to children ages 0 – 5.  Measles, however, does carry risk of permanent injury or death for young children who contract the illness.  However, measles outbreaks in the USA are currently very small, with 140 total cases in 2008 (92% vaccination rate), 71 cases in 2009 (90% vaccination rate), and 61 cases in 2010 across the entire USA with no deaths occurring from measles.

On October 26, 2009, Merck announced that it would no longer produce the separate measles vaccine, mumps vaccine, and rubella vaccine (see note 3 at Thus, the only choice today is whether to vaccinate with the combination MMR vaccine or MMRV vaccine.

Given the low incidence of measles in the USA and concerns about vaccine-injury, a parent might consider whether the timing of the vaccine (currently recommended at 12-15 months) is suitable for the child.  Any delay in vaccination, however, must be weighed against the risk of permanent injury or death if the child contracts measles.  A parent might consider individual vaccine-injury risk factors before vaccination with MMR (see A SmartVax Approach to Vaccination).  A parent might consider whether to receive the MMRV four-in-one vaccine due to the higher risk of seizures, or instead to opt to receive the MMR vaccine and then separately receive the Varicella (chicken pox) vaccine.  For information on the risks and benefits of the single Varicella vaccine, see SmartVax Approach to Varicella Vaccine.