In short
Varicella zoster virus, glycoprotein E, adjuvanted with AS01B is a recombinant vaccine designed to prevent shingles, a painful reactivation of the chickenpox virus. One authorised Phase 4 trial (2026-526934-16-00) is comparing a fractional intradermal dose against the standard full intramuscular dose in 104 participants. The trial measures antibody levels four weeks after the second vaccination to see whether the smaller dose produces a comparable immune response.
Key points
- Phase 4 trial in shingles with 104 participants now authorised to proceed.
- Compares a fractional intradermal dose against the standard full intramuscular dose.
- Primary endpoint: geometrical mean concentration of anti-E VZV antibodies four weeks after the second vaccination.
- The vaccine is a recombinant varicella zoster virus glycoprotein E adjuvanted with AS01B.
- A paediatric investigation plan for the same antigen (CRV-101) was agreed by the EMA in October 2024.
What is varicella zoster virus?
Varicella zoster virus, glycoprotein E, adjuvanted with AS01B is a recombinant vaccine. It contains a single protein from the outer surface of the varicella zoster virus — glycoprotein E — combined with an adjuvant called AS01B that strengthens the immune response. The same antigen is also known under the development name CRV-101 in a paediatric investigation plan agreed by the European Medicines Agency (EMA) in October 2024. The marketed form of this vaccine is known as Shingrix, a suspension for injection in a pre-filled syringe. The EMA record classifies the substance as a powder and suspension for suspension for injection, intended for intramuscular use.
How does varicella zoster virus work?
The vaccine presents glycoprotein E — a protein found on the surface of the varicella zoster virus — to the immune system. This trains the body to recognise the virus and produce antibodies against it. The AS01B adjuvant boosts this response, helping the immune system react more strongly. In the authorised trial, researchers measure the geometrical mean concentration of anti-E VZV antibodies four weeks after the second vaccination to assess how well the vaccine has stimulated antibody production.
Which conditions is it used or studied for?
- Shingles — a painful skin rash caused by reactivation of the varicella zoster virus, which remains dormant in the body after chickenpox. The authorised Phase 4 trial studies the vaccine in this condition.
- Prevention of varicella zoster virus (VZV) reactivation — the paediatric investigation plan agreed by the EMA covers prevention of VZV reactivation, the underlying process that leads to shingles.
How is varicella zoster virus given?
The vaccine is given by injection. The authorised trial uses two routes: a standard full dose of 0.50 ml given intramuscularly, and fractional doses of 0.1 ml and 0.05 ml given intradermally (into the skin). The EMA paediatric investigation plan describes the pharmaceutical form as a powder and suspension for suspension for injection, with intramuscular use as the route of administration.
What do the clinical trials show?
One trial is listed in the EU Clinical Trials Information System for this substance. It is a Phase 4 interventional study in shingles, now authorised to proceed, with 104 participants planned. The trial compares an intradermal fractional dose of the vaccine against the standard full intramuscular dose. Its primary outcome is the geometrical mean concentration of anti-E VZV antibodies four weeks after the second vaccination, at day 90 of the study. The aim stated in the registry is to determine non-inferiority of the antibody response after the intradermal fractional dose compared to the full dose.
What side effects are known?
The sources provided do not list specific side effects for this vaccine.