Mrna-1273.251 at a glance
Medicine class
Non-live mRNA COVID-19 vaccine.
Licensed use
Prevention of COVID-19 in people aged 6 months and older.
Administration
Injected into a muscle, usually in the upper arm, by a trained healthcare professional.
Important excipient
Contains polyethylene glycol/macrogol (PEG).
What is Mrna-1273.251 used for?
Licensed for active immunisation against COVID-19, with eligibility and product choice determined by current official recommendations.
Prevention of COVID-19 in people aged 6 months and older.
How does Mrna-1273.251 work?
Lipid nanoparticles carry temporary genetic instructions for the LP.8.1 spike protein into cells near the injection site, prompting antibody and T-cell responses. The mRNA does not enter the cell nucleus, alter DNA or replicate.
How to take Mrna-1273.251
A trained healthcare professional prepares and injects this vaccine. Food does not affect vaccination.
It is injected into a muscle, preferably in the upper arm.
Tell staff about previous severe allergic reactions, current illness, bleeding disorders and medicines that affect clotting.
The ready-to-use dispersion must not be diluted, shaken or mixed in the same syringe with another product.
Other injectable vaccines given at the same visit should use a different injection site.
Mrna-1273.251 side effects
Common or expected effects
- Injection-site pain, redness or swelling
- Tiredness
- Headache
- Muscle or joint aches
- Chills or fever
- Nausea or vomiting
- Tender or swollen lymph nodes near the injected arm
- In young children: irritability, sleepiness or reduced appetite
Get urgent medical advice
- Severe allergic reaction, including anaphylaxis
- Myocarditis or pericarditis, which may cause persistent chest pain, breathlessness or palpitations
- Rare capillary leak syndrome flare-up in someone with a previous history
Mrna-1273.251 in pregnancy
Spikevax LP.8.1 can be used during pregnancy. Direct pregnancy data for this formulation are not yet available, but substantial experience with earlier Spikevax formulations has not identified increased adverse pregnancy outcomes. Vaccination should follow current official eligibility recommendations.
Mrna-1273.251 while breastfeeding
Spikevax LP.8.1 can be used while breastfeeding. Harm to a breastfed infant is not expected, and experience with earlier Spikevax formulations has not shown adverse effects in breastfed infants.
Mrna-1273.251 interactions
Other vaccines and treatments affecting immunity or bleeding may need practical consideration.
Seasonal inactivated influenza vaccines
May be given at the same visit using separate injection sites.
Recombinant adjuvanted shingles vaccine
May be given at the same visit, although fatigue, muscle aches, chills and fever may occur more often.
Other injectable vaccines
Use a different injection site; product-specific evidence may be limited.
Common questions about Mrna-1273.251
Answers are fully visible for fast scanning and source review.
Can Mrna-1273.251 give me COVID-19?
No. It does not contain replicating SARS-CoV-2 and cannot cause COVID-19 infection.
Does Mrna-1273.251 alter DNA?
No. Its mRNA does not enter the cell nucleus or interact with the genome and is expressed only temporarily.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.