COVID-19 mRNA Vaccine: Mechanism & Action

• The generic name for the vaccine is covid-19 mRNA (bnt162b2).
• The trade name for the vaccine is Comirnaty.
• This vaccine is classified as an mRNA vaccine.
• The vaccine is administered via injection.

Mechanism of Action

• The vaccine contains nucleoside-modified mRNA encoding the SARS-CoV-2 spike protein.
• The SARS-CoV-2 spike protein is critical for viral entry into human cells.
• Lipid nanoparticles protect the mRNA from degradation.
• The lipid nanoparticles facilitate delivery into host cells.
• The mRNA is translated into spike proteins once inside the cells.
• Spike proteins are displayed on the cell surface, triggering immune responses.
• The vaccine activates neutralizing antibodies that block the virus from entering cells.
• It stimulates cellular immunity including T-cell responses.

Pharmacokinetics

• The vaccine doesn't follow typical pharmacokinetic pathways of small molecules.
• Lipid nanoparticles enable mRNA absorption into cells near the injection site.
• mRNA undergoes rapid translation to produce spike proteins inside cells.
• mRNA is transient and degrades naturally after protein translation.
• Immune responses occur locally at the injection site and systemically.
• This facilitates antibody production and cellular immunity.
• Studies suggest limited systemic biodistribution of lipid nanoparticles and spike proteins, mainly in lymphatic tissues.

Adverse effects

• Common adverse effects: injection site pain, redness, or swelling, fatigue, headache, muscle pain, chills, fever, and nausea.
• Rare but serious adverse effects: Myocarditis and pericarditis, most commonly in younger males within a few days post-vaccination, anaphylaxis, which is a severe allergic reaction that is extremely rare.

Drug interactions

• Live vaccines should not be administered simultaneously with the mRNA vaccine to avoid adverse immune interactions.
• Immunosuppressants like corticosteroids may reduce vaccine efficacy.
• Data on interactions with other pharmaceutical drugs is limited; ongoing monitoring is recommended, especially for immunosuppressive therapies.

Therapeutic Uses

• The vaccine's primary indication is active immunization to prevent COVID-19 infection caused by SARS-CoV-2.
• It can also prevent severe outcomes of COVID-19, including hospitalization and death.

Drug dosage

• The primary series consists of two doses of 30 µg each, administered 21 days apart.
• Booster doses are recommended six months after the primary series to maintain immunity.
• Additional booster doses tailored to emerging variants may be required, especially for vulnerable populations.

Nursing considerations

• Nurses ensure safe handling, storage, and administration and educate patients and monitor for adverse effects.