mRNA-1273.167: clinical use

Prescribing considerations

• Use in accordance with current official recommendations rather than the full licensed population alone.
• Postpone during acute severe febrile illness or acute infection, but not solely for a minor infection or low-grade fever.
• Take precautions against vasovagal reactions and injury from fainting.
• Assess bleeding risk before intramuscular administration in thrombocytopenia, coagulation disorders or anticoagulant use.
• Plan vaccination with relevant specialists in patients with previous capillary leak syndrome.
• A weakened immune response is possible in immunocompromised people.

Contraindications and cautions

• Hypersensitivity to mRNA-1273.167 or any excipient, including PEG-containing components.
• Do not give a subsequent Spikevax vaccination after a severe allergic reaction to an earlier Spikevax vaccination.

Monitoring

• Ensure facilities and treatment for anaphylaxis are immediately available.
• Record the product name and batch number for traceability.
• Advise recipients to seek immediate assessment for chest pain, breathlessness or palpitations after vaccination.
• Monitor clinically significant or persistent adverse reactions and report suspected reactions through the Yellow Card scheme.

Clinical pharmacology

Lipid nanoparticles deliver non-replicating mRNA encoding a stabilised full-length JN.1 SARS-CoV-2 spike protein. Transient antigen expression stimulates neutralising antibody and cellular immune responses without nuclear entry or genomic interaction.

Formulation and product differences

• The selected product is a white to off-white dispersion supplied in a multidose vial with a blue flip-off cap.
• It is ready to use after thawing and must not be diluted or shaken; gently swirl before withdrawal.
• It contains SM-102 lipid nanoparticles and PEG2000-DMG.
• Once thawed, it must not be refrozen; storage, thawing and in-use limits must follow the product-specific SmPC.