Moderna COVID-19 vaccine

The Moderna COVID‑19 vaccine, sold under the brand name Spikevax, is a COVID-19 vaccine developed by the American company Moderna, the United States National Institute of Allergy and Infectious Diseases (NIAID), and the Biomedical Advanced Research and Development Authority (BARDA). Depending on the jurisdiction, it is authorized for use in humans aged six months, twelve years, or eighteen years and older. It provides protection against COVID-19, which is caused by infection by the SARS-CoV-2 virus.

It is designed to be administered in two or three 0.5-mL doses given by intramuscular injection, primarily into the deltoid muscle, at an interval of at least 28 days apart. The World Health Organization advises an eight-week interval between doses to optimize efficacy. Additional booster doses are approved in some regions to maintain immunity. Clinical trials and real-world data have demonstrated the vaccine's high efficacy, with significant effectiveness observed two weeks post-administration of the second dose, offering 94% protection against Covid and robust defense against severe cases. The vaccine's efficacy spans various demographics, including age, sex, and those with high-risk medical conditions.

It is an mRNA vaccine composed of nucleoside-modified mRNA (modRNA) encoding a spike protein of SARS-CoV-2, which is encapsulated in lipid nanoparticles. In August and September 2022, bivalent versions of the vaccine (Moderna COVID-19 Vaccine, Bivalent) containing elasomeran/elasomeran 0-omicron (Spikevax Bivalent Zero/Omicron) were authorized for use as booster doses in individuals aged 18 or older in the United Kingdom, Switzerland, Australia, Canada, the European Union, and the United States. The second component of the version of the bivalent vaccine used in the United States is based on the Omicron BA.4/BA.5 variant, while the second component of the bivalent vaccine version used in other countries is based on the Omicron BA.1 variant. The vaccine's effectiveness against variants has been extensively studied, indicating varying degrees of protection. For instance, during the prevalence of the Delta variant, effectiveness against infection slightly decreased over time. The vaccine's longevity and continuous protection are under study, with ongoing research focusing on its duration of effectiveness, which remains partially undetermined as of the latest updates.

The safety profile of the vaccine is favorable, with common side effects including injection site pain, fatigue, and headaches. Severe reactions like anaphylaxis are exceedingly rare. Concerns regarding myocarditis, have been identified but are typically mild and manageable. The vaccine's formulation utilizes mRNA technology, encapsulated within lipid nanoparticles to ensure cellular uptake and immune system response.