COVID-19 vaccine insights: The news beyond the headlines

Vaccines against SARS-CoV-2

Two vaccines (from Pfizer-BioNTech [Comirnaty] and from Moderna [Spikevax]) are US Food and Drug Administration (FDA)–­approved for COVID-19; both utilize mRNA technology. Two other vaccines, which do not use mRNA technology, have an FDA emergency use authorization (from Janssen Biotech, of Johnson & Johnson [Janssen ­COVID-19 Vaccine] and from Novavax [Novavax COVID-19 Vaccine, Adjuvanted]).⁹

Pfizer-BioNTech and Moderna vaccines. The mRNA of these vaccines encodes the entire spike protein in its pre-fusion conformation, which is the antigen that is replicated in the host, inducing an immune response.^10-12 (Recall the earlier lock-and-key analogy: This conformation structure ingeniously replicates the exposed 3-dimensional key to the host’s immune system.)

The Janssen vaccine utilizes a viral vector (a nonreplicating adenovirus that functions as carrier) to deliver its message to the host for antigen production (again, the spike protein) and an immune response.

The Novavax vaccine uses a recombinant nanoparticle protein composed of the full-length spike protein.^13,14 In this review, we focus on the 2 available mRNA vaccines, (1) given their FDA-authorized status and (2) because Centers for Disease Control and Prevention (CDC) recommendations indicate a preference for mRNA vaccination over viral-vectored vaccination. However, we also address key points about the Janssen (Johnson & Johnson) vaccine.

Efficacy of COVID-19 vaccines

The first study to document the safety and efficacy of a SARS-CoV-2 vaccine (the Pfizer-BioNTech vaccine) was published just 12 months after the onset of the pandemic.¹⁰ This initial trial demonstrated a 95% efficacy in preventing symptomatic, laboratory-­confirmed COVID-19 at 3-month follow-up.¹⁰ Clinical trial data on the efficacy of COVID-19 vaccines have continued to be published since that first landmark trial.

Continue to: Data from trials...