Having already in the "arsenal" three vaccines against coronavirus, of Pfizer / BioNtech, Moderna and AstraZeneca and awaiting the arrival of the fourth vaccine in April, of Johnson & Johnson, the question that hangs from everyone's lips is "how do all these differ from each other;».
Pfizer / BionTech is maintained on 5 days in simple cooling, of Moderna can be stored for up to a month in the home refrigerator, AstraZeneca should only be used in people up to 64 years, while Johnson & Johnson is the only one given in a single dose. Liberal attempts through a user guide to record the most basic differences between the above vaccines, in terms of technology, the dosage, efficiency, storage and of course the contraindications.
Pfizer/BionTech (BNT162b2): Maintained 5 days in simple cooling
It is the first to be approved by the European Medicines Agency (EMA) and the first to come to Greece.
Technology: The Pfizer / BionTech vaccine is the first representative of mRNA technology and when administered to humans mimics what happens during Covid infection but without the presence of a virus. Pfizer / BionTech mRNA vaccine inserts coronavirus protein gene code into cells and leads human cells to produce spike protein, through which the virus invades our body. Unlike the "conventional" vaccines of the old technology, the mRNA vaccine does not contain any real part of the virus.
Dosage and effectiveness: The Pfizer / BionTech vaccine is given in two doses, which are far apart 21 days.
The first dose triggers the body's immune cells and the second leads them to action, to produce antibody titers (that is, protection). The second dose is very important because it causes memory, activating T lymphocytes and is therefore called a "booster" dose.
If both doses are made, then the vaccine offers 95% virus protection, while it turned out against 94% effective in the elderly over 65 years, considered the most vulnerable population group.
Recent research has shown that 7 days after the 2nd dose, the Pfizer / BionTech vaccine is 92% effective against severe Covid infection, which leads the patient to the ICU.
So far the Pfizer / BionTech vaccine has been shown to be effective against coronavirus mutations and in particular against the highly prevalent British mutation. Although vaccination does not make people non-communicable, Research has shown that administration of the Pfizer / BionTech vaccine reduces both the coronavirus viral load in the nasopharynx, which minimizes the chances of transmission. It is administered to elderly people 18 years and older.
Save: The Pfizer / BionTech vaccine should be stored at -70 ° C, in special freezers and if it comes out of the deep freezer, can be kept in simple cooling (2C to 8oC) for 5 just days. This difficulty makes it more difficult to distribute and forces the State to create a replacement mechanism., so that the excess installments are not lost from the canceled appointments.
Contraindications: According to the official regulations in force, Anyone who is allergic to the ingredients of the vaccine should not get the vaccine, which may cause an allergic reaction. Since the start of vaccinations with the Pfizer / BionTech vaccine, isolated cases of rash have been reported in people who have been given. Anaphylaxis is manifested by a rash, drop in blood pressure, shortness of breath and tachycardia. It can occur after any vaccine and is a very rare reaction, which occurs once per 1 million. vaccinated. In the Pfizer / BionTech mRNA vaccine, severe allergic reactions may be due to a component used as a mRNA transporter, which is called polyethylene glycol and is better known by the acronym PEG. Because the allergic reaction occurs shortly after vaccination, People with a history of allergies have been asked to stay at the vaccination center for half an hour (30 minutes) after dosing to eliminate the risk. If anaphylactic shock is observed, an adrenaline injection is given.
Modern (mRNA-1273) : Maintained 1 month in the home refrigerator
It is the 2nd Covid vaccine licensed in Europe but produced and distributed in smaller doses, compared to the Pfizer / BionTech and Astra Zeneca vaccines, as the company has less productive capacity.
Technology: The Moderna vaccine is the second representative of mRNA technology, which has a significant advantage: If a coronavirus mutation occurs in the future, in which vaccines have low efficacy, then with a slight modification of the platform that produces them, vaccines can be modified-in 6 weeks-to "catch" the mutation. Otherwise, Moderna's vaccine is very similar to the Pfizer / BionTech vaccine.
Dosage and effectiveness: The Moderna vaccine is given (that too) in two doses, by far 28 days or 4 weeks. After the completion of the two doses it provides protection 95% and vaccinated individuals are considered protected 7 days. The Moderna vaccine proves to be effective against coronavirus mutations and is particularly effective against the South African mutation, thanks to the mechanism of "cellular" immunity. It is given to people aged from 18 years and over.
Save: The Moderna vaccine is easier to store than the Pfizer / BionTech vaccine, as it remains constant at -20o C for 6 months (this is the temperature of a common freezer) and can be maintained up to 30 days in a home refrigerator and for 12 hours at room temperature. All these features give it a significant advantage in its maintenance and distribution.
Contraindications: The Moderna vaccine also contains the component polyethylene glycol as an mRNA transporter (PEG), so this also carries the risk of an allergic reaction — like Pfizer, but we remind you that these incidents are very rare.
AstraZeneca: It is administered to people aged up to 64 years
The vaccine developed by AstraZeneca in collaboration with the University of Oxford is the 3rd to be approved by the European AEO, but came 2nd in a row in Greece and is distributed to other vaccination centers, as it is given at certain ages — not the elderly 65 years and over.
Technology: The AstraZeneca vaccine differs from the previous two, as it is of "classic" technology. Contains a monkey adenovirus, which he uses as a vector to "smuggle" a coronavirus gene into human cells and in this way the cells create the mRNA and eventually the protein spike.
Dosage and effectiveness: The AstraZeneca vaccine is also given in two doses, but here there is a significant difference as the 2nd dose is far away 12 weeks (3 months) from the 1st. Its effectiveness after the 2nd dose is above it 90% and is the vaccine that has given the most spectacular results in reducing the risk of transmitting the infection.
However, its most characteristic feature that distinguishes it from the rest is that it has a reduced immune response in the elderly and that is why in our country and in many other EU countries it has been approved to be administered to people from 18 years to 64 years. In other words, the elderly and the elderly have been excluded. It is also not effective against the South African coronavirus mutation.
Save: The AstraZeneca vaccine is the easiest to store of the three vaccines we currently have in Greece. Store at temperatures between 2οC-8o C (simple refrigerator) and because it is much cheaper than Pfizer / BionTech and Moderna vaccines it is a potential long-term option for poorer countries.
Contraindications: In contrast to the two vaccines mentioned above, AstraZeneca vaccine does not contain the PEG ingredient blamed for rare severe allergic reactions. However, it does cause flu-like symptoms, the so-called flu like syndrome, and therefore was not administered in studies in the elderly. The symptoms subside after 3 days.
Johnson & Johnson : Only granted to 1 dose
This is the 4th vaccine that will strengthen the quiver, has applied for approval by the European Medicines Agency and is expected in April in Greece.
Technology: The Johnson vaccine & Johnson is also a classic technology. It belongs to the AstraZeneca virus carrier vaccines- and uses another harmless virus to transmit instructions to human cells.
Dosage and effectiveness: It is the only Covid vaccine given in a single dose and this gives it a significant comparative advantage.. It is effective 90% and is effective against mutations and in particular against South African mutation. It is also given to elderly people 18 years and older.
Save: It is easy to store and in combination with the fact that it is unique it is very likely to be given to pharmacies so that vaccinations can be done there and the vaccination process can be speeded up, as this will multiply the vaccination centers.
Contraindications: It is considered one of the vaccines with the fewest side effects, something that greatly enhances its friendly and reliable profile.
In the future, we are waiting for more vaccines, different technology such as those containing protein subunits developed by Sanofi and Novavax, which have advantages in storage as they can be stored at refrigerated temperatures for months.