Chicken pox vaccine (Varicella vaccine)

What is Chickenpox?

Chickenpox is a common term used for ‘Varicella’. Varicella is a common disease generally seen during childhood. Varicella is a contagious disease caused by the varicella-zoster virus (VZV).¹ This disease can be more severe in adults and can result in severe complications.

A person with chickenpox will have blister-like skin rash, itching, fever and tiredness. In severe cases, chickenpox can further result in severe skin infection, scars, pneumonia, brain damage and death.

How is the disease spread?

Chickenpox is a highly contagious disease and spreads from person to person through air or by direct contact. The virus is spread when a non-infected person comes in contact with the fluid from chickenpox blisters of a person infected with chickenpox (shingles).¹ ² People with chickenpox remain infectious for 4-7 days after the skin blisters have appeared and until all the skin blisters are crusted over.

Can disease from chicken pox be serious?

Chicken pox can get quite serious in babies, pregnant women, adolescents, adults, and people with weakened immune systems such as those with HIV/AIDs, cancer, chemotherapy or those taking steroids for a long time.

Complications of chicken pox include bacterial infections of the skin, dehydration, pneumonia, inflammation of the brain (encephalitis).

Who should get the vaccine?

  • Children who have never had chickenpox, should get minimum 2 doses of the vaccine, as per the vaccination schedule
  • Healthcare workers who have never had chickenpox or haven’t had the vaccine³, as well as people who are likely to come in contact with those with a weakened immune system? should get the chickenpox vaccine. This is to reduce the risk of infection in people who are not immunised. For an instance, if a person is suffering from cancer and is taking chemotherapy treatment, it is recommended that non-immune children close to him or her should be given chickenpox vaccine.
  • Persons who are 13 years or older (who have never had chickenpox and never received chickenpox vaccine) should get two doses at least 28 days apart.
  • Pregnant women should not take the chickenpox vaccine until they have given birth. Only after delivering the child, they can get vaccinated. For 1 month after getting the chickenpox vaccine, women should not get pregnant.

Who is at risk for getting chickenpox?

  • Majority of the times, all children develop immunity to chickenpox after the infection, and so, most catch it only once.
  • Adults can get chickenpox too. When they do, it is far worse than when it occurs in children¹?, since they have a higher risk of developing complications such as pneumonia.¹²
  • Those with a weakened immune system, or people who are suffering from chronic diseases like HIV or Cancer.?
  • Pregnant females – If a pregnant woman gets the disease, it can be very dangerous for the unborn baby. The infection can result in severe birth defects in the baby, as well as severe disease when the baby is born.?

Congenital varicella syndromeIt is a rare disorder that affects new born babies. The baby may be born with some birth abnormalities due to mother being infected with varicella during pregnancy. The risk is more through 1st 20 weeks of pregnancy. Affected baby may have low birth weight, shrunken extremities (atrophy) due to skin scarring, eye, and brain abnormalities. The risk of infection passing on to the baby is <2%.¹³

Are there any side effects?

The chickenpox vaccine is considered to be very safe. There can be some minor side effects after being vaccinated.

In 20% of the cases, there will be pain, soreness where the shot is given.

1 out of 10 people may have fever after vaccination. In less than 5% of cases, people may develop a mild skin rash up to 1 month after vaccination.?

What if a dose is missed?

It is recommended that children receive at least 2 doses for the varicella vaccine, as per the vaccination schedule; 1st dose between 15-18 months and 2nd dose at 4-6 years of age. A ‘catch-up vaccination’ with a second dose for the teenagers and adults who may have missed the second dose is recommended. For the children aged 12 months up to 12 years, the minimum gap between doses is 3 months, and for people aged 13 years and older, the minimum interval between doses is 4 weeks.¹¹



To read more on Chicken pox vaccine, click here


1 J Infect Chemother. 2013 Apr;19(2):188-95.

2 Epidemics. 2016 Dec;17:1-9.

3 J Clin Virol. 2013 Jun;57(2):109-14.

4 Ginekol Pol. 2017;88(1):13-19.

5 Pract Radiat Oncol. 2014 Jan-Feb;4(1):58-64.

6 MMWR Morb Mortal Wkly Rep. 2016 Sep 2;65(34):902-5

7 Epidemics. 2016 Nov 22. pii: S1755-4365(16)30042-1.

8 PLoS One. 2016 Sep 30;11(9):e0163636.

9 Pediatrics. 2017 Mar;139(3). pii: e20162536.

10 Hum Vaccin Immunother. 2015;11(6):1426-8.


12 Retin Cases Brief Rep. 2016 Aug 16.

13 CMAJ. 2011 Feb 22; 183(3): E169–E170.