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Vaccino mRNA COVID-19

Comirnaty, Spikevax

Updated versions of Comirnaty® and Spikevax® vaccine are available to protect against two coronavirus variants; the original 2020 strain and the Omicron variant. These are known as bivalent vaccines.

Use of all coronavirus vaccines will be closely monitored to allow quick identification of new safety information. If you develop any side-effects, you can help this important process by reporting these to the dedicated COVID-19 vaccine monitoring scheme.

Please be aware that updates to safety information may happen frequently as new data become available. Always refer to the manufacturer's printed information given to you at the time of your vaccination.

This vaccine may be offered to you as part of the UK's COVID-19 vaccination programme. People in other countries may receive this vaccine through their local programmes.

A healthcare professional will assess whether this vaccine is suitable for you before you are vaccinated. Ask your vaccinator if you have any questions or concerns.

The most common side-effects are pain at the injection site, tiredness, headache, muscle or joint pain, and chills or fever.

Ask a pharmacist to recommend a suitable painkiller in case you feel unwell. Drink plenty of fluids and rest if possible.

A colpo d'occhio

  • The COVID-19 mRNA vaccine (Comirnaty® or Spikevax®) protects against the SARS-CoV-2 virus.

  • These vaccines work by training your immune system to recognise the virus's spike protein.

  • They cannot cause COVID-19 as they do not contain the actual virus.

  • You will usually need two doses, given by injection into your upper arm.

  • Common side-effects include pain at the injection site, headache, and tiredness.

  • Seek medical attention if you experience chest pain, shortness of breath, or an irregular heartbeat after vaccination.

About COVID-19 mRNA vaccine (Comirnaty®, Spikevax®)

Tipo di medicinale

COVID-19 mRNA vaccine

Utilizzato per

Protection against infection caused by SARS-CoV-2 virus, original and Omicron variants

Chiamato anche

Comirnaty® 'Pfizer BioNTech' vaccine; 'Moderna' Spikevax® vaccine

Disponibile come

Multi-dose injection vials

SARS-CoV-2 is a strain of coronavirus that first emerged in Wuhan, China, in late 2019. It has led to the worldwide COVID-19 pandemic. Social distancing measures, travel restrictions and use of personal protective equipment have been used to help control the spread of the virus. A number of vaccines are now available as part of national vaccination programmes.

The coronavirus has a distinctive 'spike' protein on its outer coat that it uses to infect host cells. The COVID-19 mRNA vaccine contains single strands of messenger RNA that encode the spike protein. They are produced in test tubes and embedded within tiny fat particles (lipid nanoparticles). Once inside the body the mRNA strands are used as templates by your own cells to mass produce the coronavirus spike protein.

These spike proteins trigger your immune system to create antibodies that will attack the SARS-CoV-2 virus if it enters your body. They also prime other parts of your immune system - your T cells - which provide longer-lasting protection against the virus. The vaccine does not contain coronavirus and cannot cause COVID-19 disease.

In clinical trials the Pfizer BioNTech vaccine was around 95% effective at preventing COVID-19 disease from seven days after the second dose. The Moderna Spikevax° vaccine was shown to be 94.1% effective from two weeks after the second dose.

The UK COVID-19 vaccination programme aims to protect the most vulnerable people from infection, such as the elderly and those with underlying health conditions, as well as front-line healthcare workers. The remaining population will be offered the vaccination based on age-related cohorts. You will receive one of a number of different vaccines available. Wherever possible, your second dose should be with the same vaccine as your first dose.

For information on other COVID19 vaccines, see our leaflet for COVID-19 Viral-vector Vaccine (AstraZeneca, Janssen).

Before having COVID-19 mRNA vaccine (Comirnaty®, Spikevax®)

Some vaccines are not suitable for people with certain conditions, and sometimes a vaccine may only be used if extra care is taken. For these reasons, before you are given COVID-19 mRNA vaccine it is important that your vaccinator knows:

  • If you are allergic to any of the ingredients in the vaccine as listed in the manufacturer's information.

  • If you have ever had a severe allergic reaction or breathing problems after any previous vaccination.

  • If you currently have a severe illness with a high temperature (fever).

  • If you are pregnant, trying for a baby or breastfeeding (see below).

  • If you have a weakened immune system. This may be a result of an illness or taking medicines. You should still get vaccinated, but your immune response may not be as high as the general population's.

  • If you have a condition that makes you bleed more than is normal, such as haemophilia, or are taking anticoagulant medicines such as warfarin.

  • If you have recently been given any other vaccine.

COVID-19 vaccination if you are pregnant or breastfeeding

Initial trials of the vaccine did not include pregnant or breastfeeding women. As a result, in the early stages of the UK vaccination programme, it was recommended that women in these categories should discuss their personal risks with a healthcare professional.

However, it is now recommended that women who are pregnant, trying for a baby, or breastfeeding should be vaccinated in line with other people in their age or clinical risk group. This is because:

  • There are now data from over 90,000 women vaccinated against COVID-19 with no safety concerns identified.

  • Pregnant women, particularly in the last trimester of pregnancy, may be at higher risk of complications of COVID-19 infection.

Because most of the women in these groups who have been vaccinated have received Pfizer BioNTech or Moderna vaccines, the UK recommendation is that they should be given one of these vaccines.

How COVID-19 mRNA vaccine (Comirnaty®, Spikevax®) is given

  • Before you are given this vaccine, ask to read the manufacturer's printed information leaflet from inside the pack. The leaflet will give you more information about the vaccine and a full list of side-effects which you may experience from having it.

  • You will be given the vaccine by a trained vaccinator or healthcare professional.

  • The vaccine is given by injection into a muscle, usually in your upper arm. If you have a condition or take medication that makes you bleed more easily than normal, let your vaccinator know.

  • You will need two doses of the Comirnaty® vaccine given between 3 and 12 weeks apart.

  • You will need two doses of the Spikevax® vaccine, given at least 4 weeks apart.

  • The second dose of the vaccine is important to boost your immunity and prolong its duration. It is not yet known if or when further booster doses may be needed.

  • Before receiving your second dose check to make sure it is the same vaccine as your first dose. If you have any questions, ask your vaccinator for advice.

  • If you have a high temperature (fever) or are acutely unwell at the time of a scheduled vaccination, you are advised to delay having the vaccine. You should arrange for an alternative appointment for the vaccination to be given. A minor illness (such as a cough or cold) will not interfere with the vaccine.

Ottenere il massimo dal tuo trattamento

  • Try to ensure you attend both appointments for your vaccine doses. If you are unable to attend an appointment, cancel your unwanted appointment and book an alternative.

  • As a safety measure you will be observed for 15 minutes after your dose for any signs of an allergic reaction. Let someone know if you begin to feel unwell during this time.

  • It will take at least seven days after your second dose of Comirnaty® vaccine before you get maximum protection against COVID-19 infection.

  • Spikevax® vaccine may provide around 94% protection from 14 days after your second dose.

  • After you have been vaccinated continue to follow any local restrictions or guidelines to help prevent the spread of COVID-19 infection.

  • Maintain hygiene measures such as routinely washing or sanitising your hands.

  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are planning to have, or have had, the COVID-19 mRNA vaccine.

Can COVID-19 mRNA vaccine cause problems?

Along with their health benefits, most vaccines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with COVID-19 mRNA Vaccine. You will find a full list in the manufacturer's information leaflet supplied at the time of vaccination. The unwanted effects often only last for a few hours or days, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Very common COVID-19 mRNA vaccine side-effects (these affect more than 1 in 10 people)

Cosa posso fare se sperimento questo?

Pain, redness or swelling at the injection site, headache, muscle or joint pain

Drink plenty of water and ask a pharmacist to recommend a suitable painkiller. Using a cold-pack on the area may help to relieve symptoms

Tiredness (fatigue), chills or fever

Drink plenty of water and rest if possible. Ask your pharmacist to recommend a suitable painkiller

Swelling of the underarm glands on the side you were vaccinated

This should soon pass. If it persists, let your doctor know

Diarrhoea, feeling sick (nausea) or being sick (vomiting)

Drink plenty of water to replace any fluids lost. Stick to simple or bland foods - avoid rich or spicy foods

Common COVID-19 mRNA vaccine side-effects (these affect fewer than 1 in 10 people)

Cosa posso fare se sperimento questo?

(Moderna vaccine only) Rash or hives at the injection site

Ask a pharmacist to recommend a suitable antihistamine. Seek urgent medical attention if a rash develops quickly along with other signs of allergic reaction (see below)

Importante: be aware of signs of serious allergic reaction after you have been vaccinated. Seek medical attention if you experience the following:

  • Wheezing or breathing difficulties.

  • Swelling of the face, lips or tongue.

  • Hives or rash.

  • A fast or racing heartbeat.

  • Feeling faint or light-headed.

  • Feeling or being sick (nausea or vomiting) or stomach pain

Nota dell'autore clinico Michael Stewart 22/7/21: the MHRA has reviewed reports of extremely rare cases of inflammation of the heart muscle (myocarditis) and surrounding tissues (pericarditis) after vaccination with Pfizer BioNTech and Moderna vaccines. Cases were mild and and occurred most frequently in young men following their second vaccination. Individuals recovered quickly following standard treatment and rest. Seek medical attention if you experience any chest pain, shortness of breath, palpitations or an irregular heartbeat after your vaccination.

Some people have reported a sudden feeling of cold with shivering/shaking accompanied by a rise in body temperature, possibly with sweating, headache, muscle aches and feeling sick (nausea) or unwell, starting within a day of having the vaccine and usually lasting for a day or two.

If your fever is high and lasts longer than three days, or you have other persistent symptoms, speak with your doctor or a pharmacist.

Use of the vaccine will be closely monitored to allow quick identification of new safety information. If you develop any side-effects, you can help this important process by reporting these to the dedicated COVID-19 vaccine monitoring scheme.

How to store COVID-19 mRNA vaccine

  • You will not be asked to store this vaccine. The vaccination clinic must store the vaccine according to strict guidelines.

  • Undiluted Comirnaty® vaccine can be stored in a monitored medicines refrigerator for up to 31 days. Once diluted the vaccine must be used within six hours. The time of dilution should be written on the vial.

  • Unopened Spikevax® vaccine can be stored in a monitored medicines refrigerator for up to 30 days. Once pierced, the vial can be stored for up to 12 hours at room temperature.

Informazioni importanti su tutti i medicinali

Informazioni importanti su tutti i medicinali

If you have any questions about this vaccine ask a pharmacist or your vaccinator.

Segnala effetti collaterali di un medicinale o vaccino

Se si verificano effetti collaterali, è possibile segnalarli online tramite il Sito web Yellow Card.

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Domande frequenti

If I am ill on the day of my vaccination appointment, should I still attend?

If you have a high temperature or are acutely unwell when your vaccination is scheduled, it is advised to postpone getting the vaccine. You should reschedule for another appointment. However, a minor illness like a cough or cold will not generally affect the vaccine.

How soon after getting the Comirnaty® or Spikevax® vaccine can I be fully protected?

For the Comirnaty® vaccine, it will take at least seven days after your second dose to achieve maximum protection against COVID-19 infection. For the Spikevax® vaccine, you may have around 94% protection from 14 days after your second dose.

What should I do if I experience a rash or hives after getting the Moderna Spikevax® vaccine?

If you develop a rash or hives at the injection site after receiving the Moderna Spikevax® vaccine, you can ask a pharmacist to recommend a suitable antihistamine. However, if the rash develops quickly alongside other signs of a serious allergic reaction, such as breathing difficulties or swelling of the face, you should seek urgent medical attention.

What should I do if my fever or other side effects persist for several days after vaccination?

Most common side effects, such as fever, tiredness, or muscle pain, typically last only a few hours or days. If your fever is high and lasts longer than three days, or if you have any other persistent symptoms that become troublesome, you should speak with your doctor or a pharmacist.

Can I receive the COVID-19 mRNA vaccine if I have a condition that causes me to bleed easily or if I am taking blood thinners?

Yes, you can still receive the vaccine. However, it is important to inform your vaccinator if you have a condition that makes you bleed more than normal, such as haemophilia, or if you are taking anticoagulant medicines like warfarin. They will be aware of the necessary precautions for administering the injection.

Ulteriori letture e riferimenti

Informazioni sull'autoreVisualizza il profilo completo

Immagine dell'autore

Michael Stewart, MRPharmS

Responsabile Revisione Foglietti Illustrativi – Contrattista, Farmacista

BPharm (Hons), MRPharmS

Michael è un farmacista comunitario che esercita nelle Midlands e nel South Yorkshire con oltre 20 anni di esperienza nel consigliare su farmaci e condizioni mediche. Ha una solida esperienza nella formazione sanitaria, avendo prodotto e tenuto corsi di formazione per team di farmacia e personale di strutture di assistenza residenziale, inclusi infermieri. Ha anche contribuito a consigli consultivi farmaceutici per la gestione di condizioni a bassa gravità nella comunità.

Informazioni sul recensore

Immagine dell'autore

Sid Dajani

Sultan Dajani si è laureato alla London School of Pharmacy nel 1994 ed è diventato il più giovane membro eletto del consiglio della Royal Pharmaceutical Society dalla sua fondazione nel 1842.

Storia dell'articolo

Le informazioni su questa pagina sono scritte e revisionate da clinici qualificati.

  • Prossima revisione prevista: 13 giu 2027
  • 2 Jul 2024 | Ultima versione

    Ultimo aggiornamento di

    Michael Stewart, MRPharmS

    Revisione paritaria di

    Sid Dajani
verifica idoneità al vaccino antinfluenzale

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