What are the side effects of the combined MMRV vaccine?
Very common side effects
- Between 7 and 30 per cent of children who receive the MMRV vaccine experience local swelling, redness or pain at the injection site. These symptoms usually resolve with one or two days.
Common side effects
- About 15 per cent get a high fever and tiredness or lack of energy (malaise) between 5 and 12 days after they get the vaccine.
- About 5 per cent get a few varicella-like spots that appear between five and 26 days after vaccination and last for about a week.
- Up to 1.6 per cent get swollen glands, stiff neck or joint pains that can start between 10 and 14 days after vaccination.
Rare side effects
- About 0.03 per cent of children who get a first dose of MMRV vaccine experience febrile convulsions (fits). These happen when babies’ or children’s temperature (fever) goes up suddenly.
Very rare side effects
- Between 0.003 and 0.005 per cent develop a blood disorder called thrombocytopenia after their first dose of the MMR vaccine. Thrombocytopaenia causes children to bruise or bleed very easily. It usually lasts for between one and six months and then gets better.
- About 0.0001 per cent can have an allergic reaction that affects their whole body, called anaphylaxis. This reaction usually happens within 15 minutes of getting the vaccination and can be treated by giving an injection (epinephrine). People who have this reaction usually recover quickly and don’t experience any long-term effects.
- These side effects are less common after the MMRV vaccine given at 12 months because it is the second dose of a vaccine that contains MMR.
What are the symptoms of varicella (chickenpox)?
- Most children who get varicella get a fever, and between 200 and 500 itchy, fluid-filled blisters on their skin. These blisters can get infected.
- When pregnant women catch varicella their babies usually suffer serious and permanent injuries.
- As many as 33 per cent of babies born to mothers who catch varicella around the time they give birth get a severe form of varicella infection.
- About 1.4 per cent of babies whose mothers had varicella during the second trimester of their pregnancies are born with scarred skin or congenital malformations (arms, legs, eyes or brains that haven’t formed normally).
- As many as 1.6 per cent of babies whose mothers had varicella during the third trimester of their pregnancies can get shingles. Shingles (herpes zoster) causes a blistery rash, headaches, eyes that hurt in the light (photophobia), severe tiredness or lack of energy, itching, tingling and severe nerve pain.
Very rare symptoms
- About 0.025 per cent of people with varicella develop a condition called cerebellar ataxia which affects their brains and makes them unable to walk normally.
- About 0.001 per cent develop a brain infection called encephalitis.
- Varicella can also cause pneumonia (lung infection).
- Varicella can cause thrombocytopenia. Thrombocytopenia causes children to bruise or bleed very easily. It usually lasts for between one and six months and then gets better.
- Occasionally, varicella can affect people’s joint and internal organs.
REFERENCES / How vaccination has impacted the prevalence of varicella
Sheel M et al, Australian vaccine preventable disease epidemiological review series: varicella-zoster virus infections, 1998–2015; Communicable Diseases Intelligence 2018;42