Rubella and Rubella-Containing Vaccine Schedule
A 5-year-old unvaccinated girl has fever of 37.9 °C and a pink maculopapular rash that started on the face and spread to the trunk within 24 hours. She has tender enlarged occipital, posterior auricular and posterior cervical lymph nodes, and mild pain in both wrists. There are no Koplik spots, no conjunctivitis and no cough. Which schedule of vaccine doses in Saudi Arabia would have prevented this infection?
- A.At 2, 4 and 6 months of age
- B.At 9, 15 and 24 months of age
- C.At 12 months, 18 months and school entryCorrect
- D.At birth, 6 months and 9 months of age
Explanation
Tender occipital, posterior auricular and posterior cervical lymphadenopathy with a rapidly spreading fine pink rash, minimal fever, arthralgia and atypical lymphocytosis is the classical picture of rubella, and the absence of Koplik spots, cough and conjunctivitis separates it from measles. Rubella protection in Saudi Arabia comes only from the rubella component of MMR, which is given at 12 months, again at 18 months, and as a third dose at school entry. The monovalent measles-containing dose given at 9 months contains no rubella antigen, which is why the rubella-preventing schedule starts at 12 months rather than earlier and why a 9-month-based schedule would not have protected her. A series beginning at 2, 4 and 6 months belongs to the inactivated primary-series antigens such as DTaP, Hib and pneumococcal conjugate, none of which contain rubella antigen, and no rubella-containing vaccine is given at birth. Rubella itself is a mild, self-limited illness in children, and the entire rationale for the programme is prevention of congenital rubella syndrome, characterized by sensorineural deafness, cataracts, patent ductus arteriosus and blueberry muffin skin lesions. Because MMR is a live attenuated vaccine, it is contraindicated in pregnancy and in significant immunosuppression, and non-immune women identified at antenatal screening are vaccinated in the immediate postpartum period. Any suspected rubella case is notifiable, and susceptible pregnant contacts require urgent serological assessment. Two documented doses of a rubella-containing vaccine given on or after the first birthday constitute acceptable evidence of immunity.
Why each option
- A.
- These are the ages of the inactivated primary series such as DTaP, Hib and pneumococcal conjugate, which contain no rubella antigen.
- B.
- The 9-month Saudi dose is measles-containing without a rubella component, so a schedule anchored at 9 months would not prevent rubella.
- C.
- Correct. Rubella protection comes from MMR at 12 months, at 18 months and as a third dose at school entry in the Saudi schedule.
- D.
- No rubella-containing vaccine is given at birth or in the first 6 months; the vaccines at those ages are hepatitis B, BCG and the primary series.
Reference: Saudi Ministry of Health National Immunization Schedule, 2024; WHO Rubella Vaccines Position Paper, Weekly Epidemiological Record, 2020
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