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Vaccine Pregnancy: §4.6 states that no data are yet available regarding the use of Comirnaty JN.1 during pregnancy, but that a large amount of observational data from pregnant women vaccinated with the initially approved Comirnaty vaccine during the second and third trimester have not shown an increase in adverse pregnancy outcomes, and that while first-trimester data are limited, no increased risk for miscarriage has been seen. It concludes verbatim: 'Based on data available with other vaccine variants, Comirnaty JN.1 can be used during pregnancy.' For breast-feeding, §4.6 states that no effects on the breastfed newborn or infant are anticipated since systemic exposure of the breast-feeding woman is negligible, and concludes 'Comirnaty JN.1 can be used during breast-feeding.' Animal studies do not indicate harmful effects with respect to reproductive toxicity.

COVID-19 vaccine

Brand names: Comirnaty, Spikevax, Nuvaxovid

COVID-19 vaccines are immunising agents used to prevent severe disease from SARS-CoV-2 infection, available in several platforms including mRNA and adenoviral-vector formulations.

Adult dose

Dose: Active immunisation to prevent COVID-19 caused by SARS-CoV-2 — Comirnaty JN.1 only (the single product sourced in this bundle): individuals 12 years of age and older receive a single dose of 0.3 mL, which is 30 micrograms, by intramuscular injection, regardless of prior COVID-19 vaccination status. Doses for Spikevax and Nuvaxovid, the two other brands named on this page, are NOT sourced here and are not covered by this figure.
Route: Intramuscular. The preferred site is the deltoid muscle of the upper arm. Do not dilute prior to use. Each single-dose pre-filled syringe contains 1 dose of 0.3 mL; attach a needle appropriate for intramuscular injection and administer the entire volume. The vaccine should not be mixed in the same syringe with any other vaccine or medicinal product; different injectable vaccines should be administered at different injection sites.
Frequency: A single dose. For individuals who have previously been vaccinated with a COVID-19 vaccine, §4.2 directs that Comirnaty JN.1 be administered at least 3 months after the most recent dose of a COVID-19 vaccine. §4.2 adds that additional doses may be administered to individuals who are severely immunocompromised, in accordance with national recommendations. §4.1 states that use of this vaccine should be in accordance with official recommendations, so the interval and eligibility for any given campaign are set by national policy, not by this SPC.
An earlier fetch for this page returned the Comirnaty JN.1 10 micrograms/dose presentation, which is a paediatric-only strength and was correctly rejected; the current bundle carries the 30 micrograms/dose adult and adolescent presentation. || VERBATIM (§4.2): 'Comirnaty JN.1 30 micrograms/dose is administered intramuscularly as a single dose of 0.3 mL for individuals 12 years of age and older regardless of prior COVID-19 vaccination status (see sections 4.4 and 5.1). For individuals who have previously been vaccinated with a COVID-19 vaccine, Comirnaty JN.1 should be administered at least 3 months after the most recent dose of a COVID-19 vaccine.' || NO MAXIMUM DOSE IS PUBLISHED. §4.2 states a single 0.3 mL dose and then permits additional doses in severely immunocompromised individuals 'in accordance with national recommendations'. The SPC therefore sets no numeric ceiling for this indication, and maxDose is deliberately absent rather than guessed. || BRAND SCOPE. This page lists Comirnaty, Spikevax and Nuvaxovid. Only the Comirnaty JN.1 30 micrograms/dose SPC is in this bundle. Spikevax and Nuvaxovid are different vaccines with different injection volumes and different licensed age ranges; nothing above applies to them and no figure has been carried across. || STRAIN COMPOSITION. The sourced product is the JN.1-adapted formulation. Strain composition is updated by regulators between campaigns, so confirm the current formulation and its SPC against official recommendations before use.

Paediatric dose

Route: Intramuscular, preferred site the deltoid muscle of the upper arm.
Frequency: A single dose; at least 3 months after the most recent dose of a COVID-19 vaccine in those previously vaccinated.
THIS VACCINE IS NOT DOSED BY WEIGHT — dosePerKg is null and no weight calculation applies; the dose is a fixed 0.3 mL volume set by age band and presentation. Adolescents take the SAME dose as adults from the product sourced here, and the SPC does not subdivide them into a separate band: §4.1 licenses Comirnaty JN.1 30 micrograms/dose for 'individuals 12 years of age and older' and §4.2 gives 'a single dose of 0.3 mL for individuals 12 years of age and older'. That phrase — 12 years and older — is the label's own wording and is the boundary used here; no narrower adolescent age range is quoted, because the SPC states none. CHILDREN UNDER 12 ARE NOT COVERED BY THIS BUNDLE. §4.2 verbatim: 'There are paediatric formulations available for infants and children aged 6 months to 11 years. For details, please refer to the Summary of Product Characteristics for other formulations. The safety and efficacy of the vaccine in infants aged less than 6 months have not yet been established.' No dose for the 6 months to 11 years band is published here, because the SPC for those paediatric presentations was not fetched — do not scale the 0.3 mL adult volume down, and consult the correct paediatric formulation's own SPC and current official recommendations.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients listed in section 6.1 (§4.3, which is the complete text of that section)
  • No further dose of the vaccine should be given to those who have experienced anaphylaxis after a prior dose of Comirnaty (§4.4)
  • Vaccination should be postponed in individuals suffering from acute severe febrile illness or acute infection; the presence of a minor infection and/or low-grade fever should not delay vaccination (§4.4)

Side effects

  • Myocarditis and pericarditis — §4.4 states there is an increased risk following vaccination with Comirnaty. These conditions can develop within just a few days after vaccination and have primarily occurred within 14 days, more often after the second vaccination and more often in younger males. Most cases recover, but some have required intensive care support and fatal cases have been observed
  • Anaphylaxis and hypersensitivity events have been reported (§4.4)
  • Anxiety-related reactions, including vasovagal reactions (syncope), hyperventilation and stress-related reactions such as dizziness, palpitations, increases in heart rate, alterations in blood pressure, paraesthesia, hypoaesthesia and sweating, may occur in association with the vaccination process itself (§4.4)
  • Children 5 to 11 years, after 2 doses of the 10 microgram presentation — injection site pain (> 80%), fatigue (> 50%), headache (> 30%), injection site redness and swelling (>= 20%), myalgia, chills and diarrhoea (> 10%) (§4.8; a different presentation from the one dosed above)
  • Children 2 to 4 years, after the 3 microgram primary series — pain at injection site and fatigue (> 40%), injection site redness and fever (> 10%) (§4.8; a different presentation from the one dosed above)
  • Infants 6 to 23 months, after the 3 microgram primary series — irritability (> 60%), drowsiness (> 40%), decreased appetite (> 30%), tenderness at the injection site (> 20%), injection site redness and fever (> 10%) (§4.8; a different presentation from the one dosed above)
  • NOTE: §4.8 was truncated at the source-fetch limit inside the adolescent 12 to 15 years analysis, before any adult reaction table was reached. The list above is therefore NOT the adverse-reaction profile for the 12-years-and-over 30 microgram presentation dosed on this page — consult the full §4.8 of the SPC

Monitoring

  • Close observation for at least 15 minutes is recommended following vaccination; appropriate medical treatment and supervision should always be readily available in case of an anaphylactic reaction (§4.4)
  • Instruct vaccinees, and parents or caregivers, to seek immediate medical attention if they develop symptoms indicative of myocarditis or pericarditis — acute and persisting chest pain, shortness of breath, or palpitations — following vaccination (§4.4)
  • Record the name and the batch number of the administered product clearly, to improve traceability of biological medicinal products (§4.4)
  • Give with caution in individuals receiving anticoagulant therapy, or with thrombocytopenia or any coagulation disorder such as haemophilia, because bleeding or bruising may occur after intramuscular administration (§4.4)
  • Ensure precautions are in place to avoid injury from fainting (§4.4)
  • Individuals may not be fully protected until 7 days after their vaccination, and vaccination may not protect all recipients (§4.4)

Clinical monograph

How it works

They present the SARS-CoV-2 spike antigen (or instructions to produce it) to the immune system, eliciting neutralising antibody and T-cell responses that provide protection on subsequent exposure.

Prescribing in practice

  • Anaphylaxis is rare but recognised, so vaccinate where resuscitation facilities are available and observe individuals with a relevant allergy history after administration.
  • The MHRA has identified very rare thrombosis with thrombocytopenia after adenoviral-vector vaccines and rare myocarditis/pericarditis after mRNA vaccines; advise on warning symptoms.
  • Eligibility, product choice and timing follow current national immunisation programme advice.

Monitoring

Observe for immediate hypersensitivity after administration and advise reporting of delayed symptoms such as persistent severe headache or chest pain.

Counselling the patient

  • Mild arm soreness, tiredness, headache or low-grade fever for a day or two is common and expected.
  • Seek urgent care for severe or persistent headache, breathlessness, chest pain or new severe swelling after vaccination.
  • Attend for further doses as advised by the national programme.

Evidence & guidelines

Recommendations follow UKHSA/JCVI immunisation guidance and MHRA safety surveillance.

Reference: UK Green Book; Confirm identity and dosing against the manufacturer SPC (eMC) and NICE. Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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