The MMR vaccine is targeted at measles, mumps and rubella. The latter, rubella, is a cause of abortions and developmental defects in children of mothers who are infected with the virus during the first twenty weeks of pregnancy.
It is sometimes useful to look at historical papers to get a perspective of present-day issues. An advantage is that you can look at work written prior to current fuss, such as the anti-vaccine noise over the MMR vaccine over the past ten or so years, which Andrew Wakefield’s now retracted research article plays a central but by no means exclusive role.1
The rubella component of the MMR vaccine is targeted to mothers to counter infection during their first two trimesters of pregnancy.
Infection during the first trimester results in about a half of the infants being affected, falling to about one-quarter when infection occurs during the second trimester, with few effects observed for infection occurring after 20 weeks.
’Rubella kids’, like myself, have what is called congenital rubella syndrome (CRS), having one or more of three common symptoms:
- Slightly more than one-half of CRS infants have sensorineural deafness
- Somewhat less than one-half have eye abnormalities of various kinds, particularly cataracts (see illustration above) and microphthalmia (small eyes).
- Heart defects occur in approximately one-half of CRS infants.2
Rarer effects that can also be present include mental retardation, other eye defects, enlarged livers, under-sized jaws among others. There is a possible link to some cases of schizophrenia which I may explore in another article.
IMAC reports the risks as:
85% of infants infected during the first trimester of pregnancy will be born with some type of birth defect, including deafness, eye defects, heart defects, mental retardation, and more.
1 in 2 adolescents and adults have arthralgia [joint pain; this is usually temporary, with younger people recovering quicker]
1 in 6000 develop encephalitis [swelling of the brain]
[Additions in square brackets are my own.]
The virus can be passed from person to person, with people being most contagious from a week before symptoms appears to a week after. Infants with CRS, however, can infect others through shedding the virus through urine or nasal or throat fluids for up to a year. An obvious concern is passing the infection to a pregnant mother.
New Zealand has experienced several epidemics of rubella, with particularly large ones in 1959/60 and 1963/4. Since 1970, rubella vaccination has been part of the vaccine schedule in New Zealand. Outbreaks have been observed in 1990, 1993 and 1995, which have in part been attributed to the fuss following Wakesfield’s now retracted study. Approximately 1600 laboratory reported cases were noted in 1995, prior to formal notification being required.
A study by Liggins and Phillips published in 1963 examines the 1959/60 epidemic, reporting a survey of 10 general practitioners over the period of a year peaking at 50 cases observed per week. Of these cases, 89 fit the criteria for their survey, which included accurately knowing date of appearance of the characteristic rash. Of the initial 89, 15 had therapeutic abortions and 7 spontaneously aborted, leaving 69 infants for study. Of these 67, 3 died and 12 had defects of various types. 8 of the 12 with defects had multiple defects.
This is from 10 GPs surveyed: scaling it up to the whole country gives some general idea of the potential impact of this illness in the absence of vaccination.
Unfortunately long-term statistics for the nation are proving hard to come by. This is somewhat understandable given that rubella only became notifiable in New Zealand in 1996. I suspect this also lies behind the common use of the USA figures for the 1964-5 period, to quote the IMAC information page:
There were 30,000 pregnancies affected out of 12.5 million rubella cases, including 2,000 cases of encephalitis. Of these pregnancies, 5000 women had surgical abortions, over 6000 women had spontaneous abortions and among the 20,000 infants who survived pregnancy, 11,600 were deaf, 3,580 were blind and 1,800 mentally retarded.
It is interesting to see this same difficulty expressed in Liggins & Phillips’ 1963 paper, who take to indirectly inferring past major epidemics through another researcher’s survey of peak incidence’s of deafness.
Like other illnesses, rubella is periodic in that in the absence of vaccination epidemics occur every 6-9 years.
Anecdotal evidence of the impact of the epidemic is much easier to find. The van Asch School for the Deaf was once the only in the country. Services to teach the deaf were expanded then split into two regions to cope with the influx of “rubella kids” in 1946 were expanded yet again to cope with the influx from the 1960s. (See 1946 and 1963 in the van Asch School timeline.)
Rubella has also featured in our Pacific neighbours. I’ll leave you with this rather touching letter, distributed as part of an IMAC press release (PDF file):
’I was working in the paediatric wards in my first year and I was not aware at the time but I must have been caring for young children with rubella and I subsequently found myself pregnant. I was 18 and I delivered when I was
While I was still in the maternity home they detected cataracts on her eyes and she had a heart murmur and they felt that the outlook was very bleak, they didn’t think she would survive and they thought that she would be severely mentally retarded.
This was an absolutely devastating experience for me. It made me grow up in a very big way as you can imagine as a 19 year old. I was devastated at having produced a child so severely disabled, and had a huge sense of guilt; it took me a long time to resolve.
My daughter now is 33. She does not speak, she has no eyesight at all, she is completely deaf, her sensory input is through vibration and smell. As far as activities, one of the common things she does is puzzles and the sort of puzzles that you would give to a 2 year old, you know the wooden type puzzles which she does all by touch. There is also the hurt, that the relationship of a mother and a child is never able to get established, because of her disability, so that’s another, another grief.
I don’t know what her life span will be but certainly there is going to be a period of time when hopefully rubella just isn’t seen again, because certainly to have it in the early stages of pregnancy is just devastating . I wouldn’t wish it on your worst enemy. It has been very painful for me, and I think, I will carry that for the rest of my life.’
While one might argue that statistically these events are rare, the cost–financial and personal–of raising a disabled child is high and life-long.
It’s worth adding this from a CDC article on rubella vaccination: ’And, even though children may only have mild rubella disease, they should be vaccinated on schedule to help stop the spread of rubella to pregnant women.’ (H/T: @CDCgov, via @deborahblum – thanks.)
1. This article was inspired by–but is not a ’response’ to–comments made by a doctor on this forum who stated that he considered rubella considered to be a benign disease: ’Neither rubella nor mumps have an appreciable morbidity or mortality’ As a ’rubella kid’ myself, I begged to differ. (See my reply in comments to this article.) Colour me biased–being a ’rubella kid’ and all that–but while these effects might be statistically rare, they are marked, and are a lifetime burden. (To the tax payer, too, I might add!)
2. After birth, an open ’shunt’ that allows blood to pass directly from the pulmonary artery to the aortic arch closes. This shunt allows most of the blood passing through the unborn infant’s heart to bypass the lungs. In about one-half of ’rubella kids’ this remains open, which can lead to shortness of breath, so-called heart murmur, an enlarged heart, arrhythmia and slow growth.
Rubella Embryopathy: An Interim Report On A New Zealand Epidemic
G. C. Liggins and L. I. Phillips
The British Medical Journal, Vol. 1, No. 5332 (Mar. 16, 1963), pp. 711-713 (article consists of 3 pages)
Published by: BMJ Publishing Group
Stable URL: http://www.jstor.org/stable/20380036
Selected general references (other sources were also used):
Kids Health: Rubella (German Measles) [vetted by medlineplus]
WHO rubella pages (WHO = World Health Organisation)
IMAC rubella page (IMAC = Immunisation Advisory Centre [New Zealand])
More recent articles with a health/medicine-related theme in Code for life: