The Biomedical Advanced Research and Development Authority (BARDA) has agreed to provide up to $483m to assist Moderna in developing its COVID-19 vaccine candidate, but reporting from Reynald Castañeda, Pharma Writer for the Investigative News team at GlobalData, a leading data and analytics company, shows that experts are cautious about mRNA-1273’s potential to trigger sufficient immunogenicity.

Castañeda says: “From using mRNA as a vaccine strategy, to the antigen choice of the virus’ spike protein, interviewed experts noted several advantages but in the same breath voiced many concerns.”

As of 8 April, there were 115 vaccine candidates in varying stages of preclinical testing, with 78 confirmed as active programs – as per the Coalition for Epidemic Preparedness Innovations. Vaccine development has grabbed public attention as it could be a critical element in easing pandemic-related restrictions, but interviewed experts noted a vaccine in 12 to 18 months is only possible in a best-case scenario. Moderna CEO Stéphane Bancel told Goldman Sachs that under emergency use, a vaccine could be available to certain parties such as healthcare professionals in the fall of 2020*.

Castañeda continues: “While mRNA vaccine manufacturing is relatively straightforward, and is an important consideration for a pandemic of this scale, the caveat is that the mRNA may code for enough irrelevant proteins that would negatively impact immunogenicity. It is also still challenging to identify how much neutralising antibodies are needed for protection. There can be variation between assays, making it challenging to have a uniform antibody titre target.

Castañeda adds: “The choice of SARS-CoV-2’s spike protein as the vaccine’s antigen is logical for several reasons, but as with the mRNA strategy, experts pointed to several blindspots that need to be cleared up.

“The mRNA-1273 Phase I trial acis funded by the National Institute of Allergy and Infectious Diseases (NIAID) and recruited its first patient on 16 March and has a six-week recruitment period.”

*  As per news reports on 25 March