Rubella

1. Causative Organism
2. Clinical Signs, Symptoms and Complications
3. Method of Transmission
4. Prevention - Non Immunisation Methods
5. Prevention - Immunisation
6. Public Health Significance
7. Vaccine/s and Vaccination
8. Efficacy and Effectiveness
9. Availability
10. Dosage and Administration
11. Indications and Recommendations
12. Adverse Events
13. Contraindications
14. Risks vs Benefits

Causative Organism

Rubella virus is from the togavirus family. It is easily killed by heat and UV light.

Signs, Symptoms and Complications

• Symptoms are often mild and may be absent or missed in 30%-50% of cases.
• Usually a mild disease in children; adults tend to have more complications.
• Mild conjunctivitis, cervical lymphadenopathy and arthralgia may occur.
• Small petechial lesions (Focheimer spots) may be seen on the palate.
• Discrete macular rash appears on the forehead about 7 days following infection and spreads down the trunk and limbs. Splenomegaly may occur.
• The most serious complication of rubella infection is Congenital Rubella Syndrome (CRS), which results when the rubella virus attacks a developing fetus. When infection occurs during the first trimester of pregnancy up to 85% of infants will be born with some type of birth defect, including deafness, eye defects, heart defects, mental retardation and more. Defects are rare when infection occurs after 20 weeks gestation.
  

Cataracts caused by congenital rubella syndrome. Courtesy of Centers for Disease Control and Prevention.

Method of Transmission

• Spreads from person to person through the air (by coughing, sneezing) and is moderately contagious.
• The incubation period varies from 12 to 23 days.
• The disease is most contagious when the rash is erupting, but the virus can be spread from seven days before, to seven days after the rash begins.
• Because the rubella rash looks similar to other rashes, the only sure way to diagnose rubella is by a laboratory test.
  

Prevention - Non Immunisation Methods

• Respiratory diseases are difficult to control in large populations. People who are infectious with rubella should always avoid coming into contact with pregnant women.
• Post-exposure prophylaxis with immunoglobulin and vaccination in pregnant women has not been established as effective and is not recommended.
  

Prevention - Immunisation

• The major prevention method is by national immunisation programmes.
• MMR vaccines are widely available and recommended by the WHO.

Public Health Significance

• German physicians first described rubella; hence, it is commonly known as German measles.
• In 1941 an ophthalmologist reported a link between maternal rubella and congenital cataracts. A pandemic of rubella in 1964 led to recognition of an expanded congenital rubella syndrome (CRS), which includes hepatitis, splenomegaly, encephalitis, mental retardation as well as the more familiar association with deafness, cataracts and heart disease.
• Rubella has a very similar pattern to measles, epidemiologically. It has respiratory spread that is greater in crowded societies, and periodically may disappear from a geographic area only to reappear in epidemic form.
• The seriousness of CRS can be seen when reviewing the latest major American epidemic in 1964-65. 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.
• Not every country can offer free rubella immunisation and regional epidemics do occur periodically. In 2003 there were large epidemics in several Pacific Island nations.
  

New Zealand epidemiology

• Outbreaks of rubella continue to occur in New Zealand. Although rubella immunisation was offered from 1979 to all girls in year 7 (form 1), it was not offered to boys until 1992, allowing spread in the community.
• There were 100 cases 232 reported between August 1989 and February 1990, some among pregnant women, and there were three cases of CRS reported.
• The outbreaks of rubella in 1993 and a larger one in 1995 have mostly involved young adult males, who would not have been offered immunisation.
• These outbreaks emphasise the need to immunise both boys and girls to reduce the risk of exposure in pregnant women, as well as to reduce illness in men.
• Rubella has been a notifiable disease since 1996.
• In 2003 there were 26 cases of rubella notified, of which three cases were laboratory confirmed; and in 2004 there were 25 cases notified, of which three were laboratory confirmed.
• It is important that suspected cases are notified and are laboratory confirmed so that public health control programmes can limit spread. There have been no cases of CRS in New Zealand newborns reported to the New Zealand Paediatric Surveillance Unit between 1998 and 2004.

Vaccine/s and Vaccination

• Rubella vaccine is produced from a live attenuated strain (Wistar RA 27/3) of rubella virus grown in human diploid cell cultures. 
• Monovalent rubella vaccines are not widely available. Many manufacturers have ceased production and are now making only MMR vaccine. 

Efficacy and Effectiveness

A single dose of rubella (as MMR) vaccine given after age 12 months produces an antibody response in more than 95% of people. Clinical studies have demonstrated that one dose gives long term, probably life-long, immunity in more than 90% of people vaccinated.

Availability

• MMR is given in New Zealand as MMR II^® and is part of the routine schedule.
• Monovalent rubella vaccines are not available in New Zealand and are not recommended due to consistency and quality concerns.
• Measles, rubella (MR) vaccine or measles, mumps, rubella (MMR) vaccines are widely available in many countries.
  

Dosage and Administration

• MMR II^® is given at fifteen months and four years of age.
• Rubella vaccine, as in MMR vaccine, is usually administered as a subcutaneous injection (Intramuscular administration however is still immunogenic).
• It is a powder that must be reconstituted before it can be used.
• Dosage is 0.5 mL.
• There is no medical reason to give the components of MMR separately. Indeed, until the child has had all three components, they remain at risk of catching any of the 3 diseases that they have not yet been vaccinated against.
• Measles/MMR vaccine is routinely given in 2 doses. The first is generally given after age 12 months as maternal antibodies circulating in the infant may inactivate vaccine given to younger infants.  The second dose is given at least 4 weeks after the first. In many counties this is now given around the age of school entry. There is no hazard in vaccinating those who are already immune to one or two components and circulating antibody simply inactivate the vaccine components.
• If it is necessary to give the vaccine to a child under 12 months because they are at special risk, the child should receive a second dose at 15 months and a further booster dose at the normal time.
  

Indications and Recommendations

• Primary immunisation. Two doses of rubella vaccine are generally recommended. These are usually given as MMR at 15 months and an additional dose before school entry. 
• Non-immune women of child-bearing age. Routine serological screening is available in some countries. All non-immune women of child-bearing age should complete a course of immunisation before becoming pregnant. Non-immune, non-pregnant women who have had a primary course should be offered a further immunisation and retested. Non-immune pregnant women should be given rubella immunisation after delivery (it can be given with Anti-D human globulin if required).
• Health care workers and daycare staff to prevent transmission of rubella virus. Serological testing is recommended in health care workers to assess immune status. Individuals who are not immune despite completing a primary immunisation course should receive an additional dose and serology be retested. Some countries recommend health care workers who are persistent non-responders, or those who are not immunised, should be excluded from working in paediatric, obstetric and neonatal care or from looking after the immunosuppressed. MMR immunisation is recommended for health care workers to reduce the risk of transmission of measles, mumps and rubella virus in similar settings.
• International travellers. Most countries recommend immunisation of all international travellers 9 months or over, who were born after 1965. At least one and preferably 2 doses should be given.
• Household and intimate contacts of those with immunosuppression should have a primary course of immunisation to provide “ring-fence” protection. There is no evidence of risk to contacts from possible transmission of the vaccine virus.
• Outbreak control. Rubella immunisation is recommended for all individuals aged 6-9 months or over who may be susceptible to rubella (primary course not commenced or completed, negative serology or uncertain immunisation history).
  

 Adverse Events

• Malaise, fever and/or rash may occur after MMR vaccination; most commonly 7-10 days post vaccination.
• About 1/10 have discomfort or local inflammation.
• The rash which is non-infectious occurs in about 1/100 recipients.
• Transient joint symptoms (from the rubella component) are quite common, occurring in 1 in every 35 children. In adults about 15% may get temporary joint pain from the rubella vaccine virus.
• Rare complications include thrombocytopaenia occurring in 1 in every 35,000 children. Spontaneous recovery without treatment is usual.
• Aseptic meningitis occurs in 1 in every 100,000 children given the vaccine, and is related to the mumps component of the vaccine. Children recover completely.
• Encephalitis occurs in 1 in every million children given the vaccine. In most cases this is more likely to be a chance occurrence and not caused by the vaccine.
• Anaphylaxis occurs at less than 1 per million doses.
• No association has been established between MMR and autism, Crohn’s disease or ADHD.
  

Contraindications

• Anyone who has had an anaphylactic reaction to a previous dose or any component of the measles vaccine should not be given another dose.
• Live attenuated vaccines should not be given to pregnant women or those with severe congenital or acquired immune disorders (can be given for HIV infection).
• Recipients of human immunoglobulin or whole blood transfusion within the last 3-12 months.
• Parenterally administered live vaccines not administered on the same day should be administered at least 4 weeks apart whenever possible.
• Anyone with untreated malignant disease, or those who present with an acute febrile illness with a high fever.
• Some people with severe immune deficiency disease cannot be given live attenuated vaccines, as their immune system may not eradicate even an attenuated virus and infection can occur.  However, protection for these people can be enhanced by giving rubella vaccination to their household contacts.
  

Risk vs Benefits

Disease	Risks of disease	Risks of vaccine
Rubella – a highly contagious viral illness causing fever, rash, lympahdenopathy, and fetal malformations	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 1 in 6000 develop encephalitis	Mild local or systemic reaction (14.2%) Aseptic meningitis (1 per 100,000) Encephalitis (1 per million) Anaphylaxis (<1 per million).

• Link to Immunisation Handbook (2006) Chapter 11 - Rubella

1. To download the Rubella Fact Sheet. Click here