The candidates use the same mRNA tech as in the companies' commercial COVID-19 vaccine.
The multicenter, randomized, controlled, dose-selection study will evaluate the safety, tolerability, and immunogenicity of mRNA vaccine candidates against shingles. The study is aiming to enroll up to 900 healthy volunteers aged 50-69 years old. A Phase 1 section will help select the optimal mRNA vaccine candidate, dose level, dosing schedule, and formulation (frozen or freeze dry powder). The most promising candidate will be advanced into Phase 2 trials.
Having announced their plans to pursue an mRNA shingles vaccine in January and last year, Pfizer and BioNTech say they want to embrace mRNA technology and create a vaccine that can take on existing approved shingles vaccines: with a candidate that ‘demonstrates high efficacy, is well tolerated, and is efficient to produce globally.’
The mRNA shingles vaccine candidates encode different versions of glycoprotein E (“gE”) on the surface of the varicella zoster virus. The gE protein is important for viral replication and the cell-to-cell spread after reactivation of the virus in the nerve cells.
Bar set high by existing vaccines
Shingles (also known as herpes zoster or “HZ”) is an infectious disease caused by the reactivation of varicella zoster virus (“VZV”). Primary infection with VZV causes chickenpox, usually during childhood. After chickenpox, the virus remains dormant in human nerve cells and can reactivate later in life due to stress or immunosuppression.
The incidence and severity of shingles rises with age, with a marked increase in those aged 50+ (In the US, the Center for Disease Control and Prevention, CDC, recommends shingles vaccination in this age group). And with an aging global population, Pfizer and BioNTech note shingles vaccination is an ‘important global health priority’.
In the US, GSK’s Shingrix vaccine is used, while in the UK and Europe Merck’s Zostavax vaccine is also used.
Pfizer and BioNTech’s candidate will be assessed against Shingrix in the Phase 2 phase of the trial. New data, published by GSK in October, showed Shingrix has efficacy of 97% in adults aged 50+ and 91% in adults aged 70+ over a period of four years, while the Phase 3 long-term extension trial also showed the vaccine can provide at least a decade of protection.
