Comirnaty (Pfizer-BioNTech)

Spikevax (Moderna)

Vaxzevria (AstraZeneca)

Janssen (Johnson&Johnson)

It is administered intramuscularly.

Comirnaty is the trade name of the first Covid-19 vaccine manufactured by Pfizer and BioNTech, authorised for use by the European Commission in December 2020.

The nucleoside-modified vaccine is based on mRNA technology, i.e. messenger RNA that transmits the way the antigen is produced to the cells of the vaccinated subject.

Features

Comirnaty comes as a multidose vial (0.45 ml) to be diluted. When diluted, it contains 6 doses in all, 0.3 ml each.

Each dose contains 30 micrograms of vaccine in the form of lipid nanoparticles.

Comirnaty is stored at several degrees below 0 °C; its external appearance is therefore that of a white or whitish frozen dispersion (pH: 6.9-7.9).

Once thawed, it may have white to off-white opaque amorphous particles.

Vaccine storage conditions

It must be stored between -90 °C and -60 °C and must not be used after 6 months.

Once thawed, the vial cannot be frozen again.

The vaccine may be stored at a higher temperature once removed from the freezer, between 2 °C and 8 °C for a period of 5 days, and for up to 2 hours at a temperature not exceeding 30 °C.

Once removed from the freezer (<-60 °C), trays of sealed vials containing 195 vials may remain at room temperature (<25 °C) for up to 5 minutes to allow transfer between environments at ultra-low temperature. After being returned to the freezer following exposure to room temperature, the trays of vials must remain in the freezer for at least 2 hours before they can be removed again.

Thawing before dilution

To allow each vial to be diluted, it must be thawed by transferring it to an environment between 2 °C and 8 °C.

A 195-vial package to be used immediately will thaw in about 30 minutes at a temperature not exceeding 30 °C.

After the approval of the Comirnaty vaccine, manufactured by Pfizer-BioNTech, Moderna is the second vaccine that the EMA recommended granting conditional marketing authorisation on 06/06/2021.

The MODERNA COVID-19 VACCINE is indicated for active immunisation to prevent COVID-19, a disease caused by the SARS-CoV-2 virus, in subjects 18 years of age or older. The MODERNA COVID-19 VACCINE contains mRNA inserted into lipid nanoparticles. The mRNA encodes the entire SARS-CoV-2 spike protein, modified by 2 proline substitutions within the seven peptide repeat domain (S-2P), to stabilise it in pre-fusion conformation. Following intramuscular injection, the cells at the injection site and the draining lymph nodes absorb the lipid nanoparticles, which release the mRNA sequence for translation into the viral protein. The delivered mRNA does not enter the nucleus of the human cell and does not interact with the genome; it is non-replicating and its expression is transient, occurring mainly in the dendritic cells and the macrophages of the subcapsular sinuses. The SARS-CoV-2 spike protein, expressed and bound to the membrane, is then recognised by immune cells as a foreign antigen. This induces a response in both T cells and B cells, which generate neutralising antibodies that help protect against COVID-19.

The vaccine must be given intramuscularly. The preferred administration site is the deltoid region of the arm. The vaccination cycle consists of two doses (0.5 ml each) 28 days apart. Vaccinated subjects may not be fully protected for up to 14 days after receiving the second dose.

The MODERNA COVID-19 VACCINE

• is available in multi-dose vials.
• One vial contains 10 doses and each dose is 0.5 ml.
• Unopened vials must be stored frozen in a freezer between -25 °C and -15 °C and in the original package, to protect the vaccine from light.
• it must be thawed before use (2 hours and 30 minutes in a refrigerator between 2 °C and 8 °C, or 1 hour at room temperature between 15 °C and 25 °C).
• Once thawed, the vaccine must not be refrozen. The vaccine, in unopened (non-perforated) vials, may be stored in a refrigerator between 2 °C and 8 °C, protected from light, for a maximum of 30 days and may be stored between 8 °C to 25 °C for up to 12 hours after it has been taken out of the freezer.
• Once thawed, the vaccine is ready to use. The vial must not be diluted.
• The vial must not be shaken. After thawing and before each withdrawal, gently rotate the vial. Ten (10) doses (0.5 ml each) can be withdrawn from each vial.
• The dose in the syringe must be used immediately.
  After the withdrawal of the first dose (perforated vial), the vial is chemically and physically stable for 6 hours between 2 °C to 25 °C.
• For each vial, the date and time of first use should be written on the vial label; the perforated vial must be discarded 6 hours after the first perforation.
  

The Astrazeneca vaccine is classified as a viral vector vaccine.

Vaccine type	Viral vector vaccine
How does it work? What does it contain?	A vaccine consisting of a viral vector derived from a weakened version of chimpanzee adenovirus, modified to encode the Spike protein of SARS-CoV-2. After administration, the Spike protein stimulates the immune response. (The adenovirus is unable to replicate and therefore cannot spread in the body of the vaccinated person).
When can I receive this vaccine?	For adults 18 to 65 years of age included*
How is it administered?	By intramuscular injection. 2 doses, 4-12 weeks (28 to 84 days) apart. To increase its effectiveness, the second dose is usually given in the 12th week
When does protection start?	Vaccine recipients may not be fully protected until 15 days after the second dose. Overall, the estimated efficacy from clinical trials (after two doses of vaccine) is 59.5%. In recipients who received the second dose 12 weeks after the first dose, efficacy 14 days after the second dose was 82.4%.
Most common (> 1 in 10 people) and common side effects (up to 1 in 10 people)	Very common Pain, warmth, itching or bruising at the injection site; general fatigue or malaise; chills or feeling feverish; headache; nausea; joint pain or muscle pain. Common Swelling or erythema in the site of injection; fever (>38°C); vomiting or diarrhoea.

Adverse reactions are limited in most cases to pain in the injection site and fatigue; symptoms such as fever or muscle pain are very rare.

Vaccination should be postponed in individuals with severe acute infections (such as high fever), while mild infections (cold, mild fever) do not affect vaccination. One contraindication is an allergic reaction to a dose of the vaccine.