Amezosvatein is an investigational non-mRNA adjuvanted sub-unit vaccine for the prevention of shingles (herpes zoster) in adults and chickenpox (varicella) in children. As a sub-unit vaccine, amezosvatein does not contain virus components and cannot cause infection. Amezosvatein targets glycoprotein E (gE) on the varicella virus, a target proven by others to be safe and effective for the prevention of shingles. The adjuvant component of amezosvatein was specifically engineered with the intent of producing an optimal immune response while improving tolerability. Our adjuvant has also been optimized for improved manufacturability, potentially allowing us to make amezosvatein more accessible if approved.
Amezosvatein for Chickenpox
Chickenpox (varicella) is the primary or first infection of the varicella zoster virus (VZV), which most people experience before they become an adult. It is highly contagious and can cause serious health issues, and even death, in unvaccinated young children. Older children or adults with compromised immune systems can also get very sick from the disease. Chickenpox during pregnancy can cause birth defects or life-threatening infection in newborns.
Why a New Chickenpox Vaccine?
The current chickenpox vaccines are wonderful examples of safe and effective vaccines. They make a big difference in reducing morbidity and mortality related to chickenpox. All current chickenpox vaccines are live-attenuated virus (LAV) vaccines, which means they contain the whole varicella zoster virus, but in weakened form.
LAVs can be difficult to give to children and younger adults who have compromised immune systems. Children with cancer, for example, often must pause therapy to allow their immune system to recover enough to be safely vaccinated with an LAV vaccine. Children with organ transplants may have to pause or reduce their anti-rejection medications to get the LAV vaccines. And children with genetic or acquired immune deficiencies present even greater problems for LAV vaccines.
Phase 1 Chickenpox Trial
As a adjuvanted subunit , non-mRNA vaccine, amezosvatein may not have the same limitations as LAVs. The next step in this program is a Phase 1 trial of amezosvatein in immunocompromised children to address this unmet medical need.