From the Guidelines
Chickenpox typically provides lifelong immunity for most people, but not always, as the varicella-zoster virus can reactivate later in life as shingles, especially during periods of weakened immunity. After recovering from chickenpox, the body produces specific antibodies and memory cells that recognize and fight the virus if exposed again [ 1 ]. However, a second case of chickenpox can occur, particularly in immunocompromised individuals. Some key points to consider include:
- Most adults (85%-95%) with negative or unknown histories of varicella are likely to be immune [ 1 ]
- Primary varicella can be more severe among adults than it is among normal children, but the risk of serious complications among normal adults is substantially less than it is among those who are immunocompromised [ 1 ]
- Live, attenuated varicella-zoster vaccine may be used to provide long-lasting protection, though some vaccinated individuals may experience breakthrough infections that are usually milder than natural chickenpox. For those who never had chickenpox, vaccination is recommended with two doses given 4-8 weeks apart for children and 4-8 weeks apart for adolescents and adults to provide the best protection against both chickenpox and reducing the risk of developing shingles later in life.
From the Research
Immunity to Chicken Pox
- Chicken pox, caused by the varicella-zoster virus (VZV), typically provides lifelong immunity after a natural infection 2, 3.
- However, the virus can reactivate later in life, causing herpes zoster (shingles) 2, 4, 5.
- Studies have shown that vaccination with the live attenuated varicella vaccine can provide protection against varicella, but its effectiveness in preventing herpes zoster is still being researched 4, 5, 6.
Comparison of Natural and Artificial Immunity
- Natural infection with VZV induces higher antibody levels and lymphocyte stimulation responses compared to vaccination 3.
- Vaccination, however, can still provide protection against varicella and reduce the risk of herpes zoster 4, 5, 6.
- The live attenuated varicella vaccine has been shown to be effective and safe, with universal vaccination almost eliminating varicella 6.
Long-Term Immunity
- Long-term follow-up data on individuals who received varicella vaccine as healthy young adults showed a similar incidence of herpes zoster compared to the prevaccine era 4.
- Booster immunization with the varicella vaccine may enhance cell-mediated immune responses and reduce the risk of herpes zoster in aging individuals 5.