The Disease

Chickenpox is usually a mild disease. Most children catch chickenpox before the age of five and 90% have had it by the age of ten.^{1 2 3}

The incubation period (the time from contact with someone with the illness to the first signs of developing the disease) is usually 14-17 days, though may be as long as three weeks.

It is very infectious and spreads easily from child to child. The rash is often the first sign of the illness, though this may follow a day or two of feeling unwell with a temperature. The rash is unlike that in other common infectious diseases: it consists of small itchy blisters all over the body, but concentrated on the chest, tummy and back. The blisters crust and heal over a period of about a week, only rarely leaving a permanent scar, usually as a result of overenthusiastic scratching. The vast majority of sufferers are only mildly, if at all, ill and make a complete recovery. Adults with chickenpox are generally more unwell than children, and also more prone to complications.⁴ The most common complication of chickenpox is skin infection, especially after lots of scratching; this may require antibiotics. Other problems are rare in children with a healthy immune system but include pneumonia (more common in adults); encephalitis (infection of the brain) from which full recovery is usual; arthritis; kidney or liver infection.

An infection usually provides life-long protection and it is rare to get a second attack of chickenpox. However, the virus remains in the body and can re-emerge to cause an attack of shingles, a condition that usually affects older people, which can cause an uncomfortable rash that is sometimes followed by prolonged pain (neuralgia) in the area of the rash.

The Vaccine

Though chickenpox vaccine is available it is not offered as part of the UK national immunisation schedule. The vaccine is ‘live’, containing live chickenpox (varicella zoster) virus that has been altered (attenuated) to become relatively harmless.

1 dose of chickenpox vaccine is very effective (90%) for around a year, but protection then wears off rapidly.⁵ A single dose only provides 62% long-term protection whereas two doses provides 94% long-term protection.⁶

The vaccine can also be given to prevent chickenpox after coming into contact with someone with the disease, provided it is given within 3-5 days of exposure.⁷

Common side effects include pain and swelling at the injection site, fever and a chickenpox rash.⁸ It can rarely cause convulsions. Like many other vaccines, it probably causes occasional immune-related disorders such as erythema multiforme (a potentially life-threatening skin disorder), thrombocytopaenia (a shortage of platelets in the blood causing bleeding problems), and neuropathies such as Guillain-Barré syndrome.⁹ As the vaccine contains live, though modified, virus, it can cause attacks of chickenpox in some children.^{10 11} In the same way that shingles can develop later in life in someone who has had chickenpox, so shingles can also occur after vaccination; one would expect it to occur much less commonly after vaccination but, as the time lag between catching naturally occurring chickenpox and developing shingles is usually several decades, only time will tell.¹²

It is possible to catch chickenpox from vaccinated children, though this is very rare.^{13 14 15}

The choices

Varilrix
Type of vaccine:	Single live chickenpox vaccine
Manufacturer:	GlaxoSmithKline
Protects against:	Chickenpox
Active ingredients:	Oka strain of varicella-zoster virus
Mercury content:	Nil
Aluminium content:	Nil
Other ingredients:	Human cell culture
Primary course:	2 doses separated by 6 weeks to 6 months
Boosters:	Required for long-term protection only if a single dose was given as the primary course. Immunity can be checked with a blood test if wished.

The supply of single and small combination vaccines may change over time. At BabyJabs we are on the constant lookout for safe and effective vaccines to offer your child. We may obtain different vaccines to those listed above. We will only offer you alternative vaccines if we are completely confident of their safety and efficacy.


Go back to vaccines at a glance

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¹ Joseph CA. Noah ND. Epidemiology of chickenpox in England and Wales, 1967-85. British Medical Journal Clinical Research Ed. 1988; 296(6623): 673-6.

² Bramley JC. Jones IG. Epidemiology of chickenpox in Scotland: 1981 to 1998. Communicable Disease & Public Health 2000; 3(4): 282-7.

³ Hambleton S. Arvin AM. Chickenpox party or varicella vaccine? Advances in Experimental Medicine & Biology 2005; 568: 11-24.

⁴ Ramet J. Weil-Olivier C. Sedlak W. Confederation of the European Specialists of Paediatrics (CESP)/European Academy of Paediatrics (EAP) CESP/EAP. Is Europe ready to embrace a policy of universal varicella vaccination? International Journal of Clinical Practice 2005; 59(11): 1326-33.

⁵ Bayer O, Heininger U, Heiligensetzer C, von Kries R. Metaanalysis of vaccine effectiveness in varicella outbreaks. Vaccine 2007; 25: 6655-6660.

⁶ Spackova M, Wiese-Posselt M, Dehnert M, Matysiak-Klose D, Heininger U, Siedler A. Comparative varicella vaccine effectiveness during outbreaks in day-care centres. Vaccine 2010; 28: 686-691.

⁷ Macartney K, McIntyre P. Vaccines for post-exposure prophylaxis against varicella chickenpox) in children and adults. Cochrane Database Systematic Reviews 2008; 3: CD001833.

⁸ Sharrar RG et al. The postmarketing safety profile of varicella vaccine. Vaccine 2000; 19(7-8): 916-23.

⁹ Wise RP. Salive ME. Braun MM. Mootrey GT. Seward JF. Rider LG. Krause PR. Postlicensure safety surveillance for varicella vaccine. JAMA 2000; 284(10): 1271-9.

¹⁰ Levy O et al. Disseminated varicella infection due to the vaccine strain of varicella-zoster virus, in a patient with a novel deficiency in natural killer T cells. Journal of Infectious Diseases 2003; 188(7): 948-53.

¹¹ Gershon AA. Varicella vaccine: rare serious problems--but the benefits still outweigh the risks. Journal of Infectious Diseases 2003; 188(7): 945-7.

¹² Liang MG. Heidelberg KA. Jacobson RM. McEvoy MT. Herpes zoster after varicella immunization. Journal of the American Academy of Dermatology 1998; 38(5 Pt 1): 761-3.

¹³ Salzman MB. Sharrar RG. Steinberg S. LaRussa P. Transmission of varicella-vaccine virus from a healthy 12-month-old child to his pregnant mother. Journal of Pediatrics 1997; 131(1 Pt 1): 151-4.

¹⁴ LaRussa P. Steinberg S. Meurice F. Gershon A. Transmission of vaccine strain varicella-zoster virus from a healthy adult with vaccine-associated rash to susceptible household contacts. Journal of Infectious Diseases 1997; 176(4): 1072-5.

¹⁵ Grossberg R. Harpaz R. Rubtcova E. Loparev V. Seward JF. Schmid DS. Secondary transmission of varicella vaccine virus in a chronic care facility for children. Journal of Pediatrics 2006; 148(6): 842-4.