Chickenpox Vaccine Injection

• Type: Live attenuated vaccine

• Protects Against: Varicella (chickenpox) caused by the varicella-zoster virus

• Form: Single-dose or multi-dose vial for subcutaneous injection

How It Works

• The vaccine contains a weakened (attenuated) form of the varicella virus.

• When injected, it stimulates the immune system to produce antibodies and develop immune memory.

• This helps the body recognize and fight the virus if exposed in the future, preventing illness or making it much milder.

Common Uses

• Routine vaccination of children (usually given at 12–15 months, with a booster at 4–6 years)

• Protection for susceptible adults who never had chickenpox or were not previously vaccinated

• Post-exposure prophylaxis (if given within 3–5 days of exposure, can prevent or lessen illness)

Advantages

• Highly effective in preventing chickenpox (about 90–95% protection after 2 doses)

• Greatly reduces the severity of disease in breakthrough cases

• Helps prevent complications like pneumonia, encephalitis, or severe skin infections

• Contributes to herd immunity, reducing outbreaks in the community

Possible Side Effects

Usually mild and short-lived:

• Pain, redness, or swelling at injection site

• Mild fever

• Mild rash (resembles a few chickenpox spots)
  Rare but serious:

• Severe allergic reaction

• Seizures (febrile convulsions, very rare)

Precautions

• Not given to:

  • Pregnant women

  • People with severe immune system suppression (e.g., from chemotherapy, HIV with low CD4 count)

  • People allergic to neomycin or gelatin (components of the vaccine)

• Delay vaccination in patients with high fever or severe illness until recovery

• Avoid pregnancy for at least 1 month after vaccination

• Avoid close contact with immunocompromised people if vaccine-related rash develops