What is chickenpox?
Varicella (also called chickenpox) is a very contagious viral disease. It is caused by the varicella zoster virus.
 
What is chickenpox symptoms?
A blister-like rash, itching, headache, tiredness, and fever. Chickenpox is usually mild, but it can be serious in infants under 12 months of age, adolescents, adults, pregnant women, and people with weakened immune systems.
More serious complications include skin infections, pneumonia, encephalitis or meningitis (brain inflammation), blood stream or joint infections.
 
Why should get vaccinated?
Getting vaccination can prevent the disease. Most people who get chickenpox vaccine will not get chickenpox of if they get it, the disease is less serious and symptoms are mild including fewer blisters, are less likely to have a fever, and will recover faster.
 
Who should get vaccinated against chickenpox vaccine?

• A person who have never had chickenpox or received chickenpox vaccine.
• People who have only had 1 dose of chickenpox vaccine need to get a second dose.
• A person who are exposed to someone with this disease or shingles and do not have immunity against chickenpox, he should get chickenpox vaccine within 3 to 5 days of being exposed.

 
When should get chickenpox vaccine?
Usually 2 doses of chickenpox vaccine are given subcutaneously.
 

Age	First Dose	Second Dose
12 months-12 years old	12 through 15 months of age	4 through 6 years of age (or sooner as long as it’s 3 months after the first dose)
13 years of age and older	Anytime	at least 4 weeks after the first dose

What should be done if chickenpox vaccine series was not completed?

Contact your doctor if you will miss a booster dose or if you get behind schedule. The next dose should be given as soon as possible. There is no need to start over. Be sure to receive all recommended doses of this vaccine. You may not be fully protected against disease if you do not receive the full series.

Who should not get chickenpox vaccine or should wait?

• People who have had a life-threatening allergic reaction to a previous dose of chickenpox vaccine or any ingredient in the vaccine (gelatin or the antibiotic neomycin).
• Pregnant women should wait to get chickenpox vaccine until after they have given birth. Women should not get pregnant for 1 month after getting chickenpox vaccine.
• People who are moderately or severely ill at the time the shot is scheduled should usually wait until they recover.
• Some people should check with their doctor whether they should get chickenpox vaccine if they:
  • Have HIV/AIDS or another disease that affects the immune system.
  • Have any kind of cancer.
  • Are being treated with drugs that affect the immune system, such as steroids, for 2 weeks or longer.
  • Have recently a transfusion or were given other blood products (such as plasma).
  • Are taking salicylates (such as aspirin). People should avoid using salicylates for 6 weeks after getting varicella vaccine.

 

What are the possible side effects of chickenpox vaccine?

A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions. Most people who get chickenpox vaccine do not have any problems with it. Reactions are usually more likely after the first dose than after the second. Side effects are usually mild and go away in a few days. Getting chickenpox vaccine is much safer than getting chickenpox disease.

Mild events	Pain, swelling, itching, or redness at the site of the shot Low fever Mild rash
Moderate to severe events	อาการชักจากไข้สูง (พบน้อยมาก) ปอดอักเสบ (พบน้อยมาก)

 

Interactions between chickenpox vaccine and other drugs

Some medicines may interact with this vaccine. Tell your health care provider if you are taking any other medicines, especially immunosuppressive therapy (e.g., cyclosporine, azathioprine, methotrexate) because it may result in an increased risk of infection.
Mump-Measles-Rubella vaccine could be administered on the same day. If not, the vaccine administered second should be separated by at least 1 month to minimize the potential risk of immune interference.

References

• Centers for Disease Control and Prevention. Varicella (Chickenpox) Vaccine: What You Need to Know. Available from: https://www.cdc.gov/vaccines/hcp/vis/vis-statements/varicella.html [Accessed 24 December 2021].
• Division of Vaccine Preventable Diseases, Department of Disease Control, Ministry of Public Health. (2019). Textbook of Vaccines and Immunization, 2019. (1^st Edition). Work Printing Company Limited. Available from: https://www.dropbox.com/s/39t8lkzfvuk0mvw/DDC_Vaccines-n-ImmuneSystem2562.pdf?dl=0 [Accessed 24 December 2021].