Rubella: We vaccinate for far less

Nov 10, 2021

More than 300,000 kids aged 5-11 year olds have been vaccinated with the Pfizer COVID19 vaccine. The vaccine is safe and has significant individual-level benefit for kids: prevents infection, disease, death, prevents long COVID19, and will keep kids in school. COVID19 is the 8th leading cause of death for 5-11 year olds and over 8500 5-11 year olds have been hospitalized (30% of hospitalized kids have no underlying conditions). With the new authorization, COVID19 is now a vaccine-preventable disease for 5-11 year olds.

Some vaccine skeptics don’t find the individual-level benefit convincing and say we’re “just” vaccinating kids for population-level benefit, like reducing transmission. But vaccinating for population-level benefit is not new. It came to my attention that many people are unaware of this.

For example, take Rubella...

Rubella, which is the “R” in the MMR vaccine, is caused by a virus that spreads in airborne droplets from coughing or sneezing.

Rubella outbreaks are hard to contain because people are infectious one week before symptoms arise. It’s also very contagious. The R(0) for rubella is 6-7. In other words, each infected person will infect, on average, 6-7 other people.

Symptoms of infection among children are mild with few noticeable symptoms:

Red rash
Sore throat
Low grade fever
Mild pink eye
Discomfort

About 25 to 50% of children will not experience any symptoms.

But, yet, rubella is mandated for children in all 50 states. If children have mild disease, then why vaccinate?

Population-level benefit

Rubella is incredibly dangerous for pregnant people and their developing baby. A person infected with rubella during the first 3 months of pregnancy has a 90% chance of the baby not surviving or developing a severe of illness called “Congenital Rubella Syndrome (CRS)”. CRS can result in deafness, blindness, heart defects, and severe permanent brain damage.

We learned most about rubella during a massive outbreak in the mid-1960s. From 1962–1963, a rubella epidemic broke out in Europe which eventually spilled over to the United States. From 1964-65, an estimated 12.5 million cases were reported across the country. Despite warnings about keeping infected children away from pregnant women, nearly 50,000 pregnancies were impacted. This led to >11,000 fetuses miscarried, died in the womb, or aborted. Of the >20,000 infected infants born alive, the majority had severe illnesses: 2,100 died shortly after birth, 12,000 were deaf, 3,580 were blind, and 1,800 had permanent mental disabilities.

Rubella vaccine

Shortly after this epidemic, the rubella vaccine entered clinical trials. In 1969, it was approved for use in Europe and North America. In 1971, the rubella vaccine was combined with measles and mumps vaccines for what we have today: MMR vaccine.

MMR does have very rare side effects. It’s been linked with a very small risk of febrile seizures (seizures caused by fever). They are rare and are not associated with any long-term effects. The vaccine also rarely causes a temporary low platelet count, which can cause a bleeding disorder. It usually goes away without treatment and is not life threatening.

So, there was an international debate on who should get the vaccine. There were essentially two options:

Universal vaccination. This would stop rubella transmission by vaccinating the reservoir (i.e. children), thus providing indirect protection of unvaccinated women. There are rare, but real side effects of the vaccine. But benefits outweigh risks.
Only vaccinate adolescent girls and women of childbearing age. This strategy would directly protect women at risk of being infected when pregnant, but would also allow the virus to circulate.

Ultimately, the WHO found that countries that chose #2 were not able to eradicate the virus. Not enough women got the vaccine and the virus continued to spread, causing epidemics and, thus, did not decrease rates of CRS. In 2011, the WHO stated that countries needed a combination of #1 and #2 for ultimate control of rubella.

A display used to educate the public on rubella vaccination and the mother-to-fetus transmission of this virus. Centers for Disease Control and Prevention via Public Health Image Library

The United States opted for universal vaccination. To interrupt transmission of rubella, we needed a herd immunity threshold of approximately 83-85%. And we eventually reached this. The last large United States outbreak was in 1995. Then, rubella went into an endemic state.

In 2004, rubella was fully eliminated in the United States. In 2015, it was eliminated in the Americas (35 countries in North and South America).

In present day, there is an annual average of 10-15 cases of CRS in the United States, but this is stemmed from international travel. Rubella is not eliminated in other parts of the world. In places without the vaccine, about 120,000 children are born each year with severe birth defects attributed to rubella.

Rubella compared to COVID19 vaccines

I threw together a table comparing the two viruses and vaccines. As you can see, there are striking similarities: high R(0), high asymptomatic rate, vaccine recommended for all 5-11 year olds, and very rare (but real) vaccine side effects. But there are also differences: COVID19 vaccine will prevent more death and more illness among children.

Bottom Line: As a country, we came together to eliminate rubella for the entire population. COVID19 pediatric vaccine will have a population-level benefit too. Thankfully the COVID19 vaccine also comes with significant individual-level benefit, as kids are far from spared from SARS-CoV-2.

Love, YLE

“Your Local Epidemiologist (YLE)” is written by Dr. Katelyn Jetelina, MPH PhD— an epidemiologist, biostatistician, professor, researcher, wife, and mom of two little girls. During the day she has a research lab and teaches graduate-level courses, but at night she writes this newsletter. Her main goal is to “translate” the ever-evolving public health science so that people will be well-equipped to make evidence-based decisions, rather than decisions based in fear. This newsletter is free thanks to the generous support of fellow YLE community members. To support the blood, sweat, and tears, please consider subscribing here: