Varicella is a common infectious disease with a high propensity for outbreaks among pediatric populations in many countries worldwide, including Vietnam.
According to the WHO and the America CDC, varicella vaccination in children with a prior history of infection is considered safe. Photo: Naviva Group
Live attenuated varicella vaccines have been validated as an effective and durable preventive measure; among these, the MAV/06 strain has increasingly attracted attention for its favorable safety profile and its ability to induce stable, long-lasting immunity.
In clinical practice, whether a child with a prior history of varicella requires vaccination remains a common question raised by healthcare professionals.
To address this, it is essential to distinguish between immunity acquired through natural infection and vaccine-induced immunity.
Following varicella infection, most children develop immunity to the varicella-zoster virus (VZV); however, the level of protection is variable and depends on factors such as disease severity, age at infection, and overall health status.
Children who experience very mild disease or are infected at an early age may develop a weaker and less durable immune response; in addition, some cases may be misdiagnosed, leading to uncertainty regarding prior infection history [1].
Numerous studies have reported a risk of varicella recurrence when immunity wanes, particularly in children who previously had mild disease associated with low antibody levels.
The US CDC also confirms that the varicella-zoster virus (VZV) remains latent in nerve ganglia and may reactivate when immunity declines, resulting in herpes zoster (shingles) [1].
In this context, varicella vaccination serves as an important tool to reinforce immunity. The live attenuated varicella vaccine derived from the MAV/06 strain has been developed to effectively stimulate a robust immune response.
Preclinical and clinical data demonstrate that the MAV/06 strain induces a robust anti-VZV IgG antibody response while also activating cell-mediated immunity—a key factor in controlling latent viral infection. Protective efficacy is estimated at approximately 80–90% against varicella of all severities and exceeds 95% for severe cases [2,3,4].
According to the World Health Organization and the US CDC, varicella vaccination in children with a prior history of infection is considered safe. Post-vaccination reactions are generally mild and transient, with no evidence of viral reactivation, herpes zoster, or any serious adverse events reported [3,4].
Both the WHO and the CDC recommend varicella vaccination in cases of uncertain infection history, very mild prior disease, infection at an early age, or when long-term immune protection needs to be reinforced [5].
The MAV/06 strain varicella vaccine – Barycela serves as a safe and effective immunological booster, contributing to sustained protection and long-term pediatric health.
| BARYCELA Inj., a next-generation varicella vaccine developed by GC Biopharma from the MAV/06 strain, demonstrates immunogenicity and safety comparable to Oka strain–based vaccines and can be administered in accordance with the current two-dose schedule [10].
Recommended Two-Dose Schedule for Optimal Immunity Children aged 12 months to 12 years:
In Vietnam, NAVIVA GROUP is the authorized distributor of the second-generation MAV/06 varicella vaccine under the brand name BARYCELA Inj. (GC Biopharma – South Korea). With over 21 years of experience in vaccines and biological medical products, NAVIVA GROUP collaborates with healthcare institutions to enhance community access to safe, effective, and high-quality vaccination. The company is committed to ensuring a stable supply and strict compliance with GSP/GDP standards in storage and distribution, while actively supporting initiatives to raise awareness of proactive and safe immunization practices. 📞 Hotline: 0905 584 666 |
References
Centers for Disease Control and Prevention (CDC)– Chickenpox Vaccine Recommendations: https://www.cdc.gov/chickenpox/hcp/vaccine-considerations/index.html
CDC–About the Varicella Vaccine: https://www.cdc.gov/vaccines/vpd/varicella/hcp/about-vaccine.html
World Health Organization (WHO). Varicella and herpes zoster vaccines: WHO position paper – November 21, 2025: https://www.who.int/publications/i/item/who-wer10047-567-590
Hong K et al. Effectiveness of two-dose varicella vaccination: Bayesian network meta-analysis. Pediatr Infect Vaccine. 2024;31(1):55–63.
CDC – Chickenpox (Varicella) Vaccine Safety: https://www.cdc.gov/vaccine-safety/vaccines/varicella.html
