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Trucks with the first Covid-19 vaccines left Pfizer’s headquarters in Belgium this morning. You learn in Brussels. The trucks left in the morning for various countries from Puurs in Belgium. In Italy they will arrive on the 26th at Spallanzani in Rome.
Meanwhile, AIFA – the Italian Medicines Agency takes stock of all the characteristics of the vaccine, the methods of administration, its effectiveness, possible reactions and contraindications.
The identikit of the vaccine
1. What is it and what is it used for?
The COVID-19 mRNA BNT162b2 vaccine (Comirnaty) is a vaccine intended to prevent coronavirus disease 2019 (COVID-19) in people 16 years of age and older. It contains a molecule called messenger RNA (mRNA) with instructions for making a protein found in SARSCoV-2, the virus responsible for COVID-19. The vaccine does not contain the virus and cannot cause disease.
2. How is it administered?
The COVID-19 mRNA BNT162b2 vaccine (Comirnaty) is given in two injections, usually into the muscle of the upper arm, at least 21 days apart.
3. How does it work?
SARS-CoV-2 viruses infect people using a surface protein, called Spike, which acts as a key that allows viruses to enter cells, where they can then reproduce. All the vaccines currently under study have been developed to induce a response that blocks the Spike protein and thus prevents cellular infection. The COVID-19 mRNA BNT162b2 vaccine (Comirnaty) is made with messenger ribonucleic acid (mRNA) molecules that contain instructions for the cells of the vaccinated person to synthesize Spike proteins. In the vaccine, the mRNA molecules are inserted into a microscopic lipid vesicle that allows the mRNA to enter the cells. Once injected, the mRNA is absorbed into the cytoplasm of the cells and initiates the synthesis of Spike proteins. The proteins produced stimulate the immune system to produce specific antibodies. In those who have been vaccinated and are exposed to a viral infection, the antibodies thus produced block the Spike proteins and prevent their entry into cells. Furthermore, vaccination also activates the T cells that prepare the immune system to respond to increased exposure to SARS-CoV-2 The vaccine therefore does not introduce the actual virus into the vaccinator’s cells, but only the genetic information that the cell needs to make copies of the spike protein. If the vaccinated person comes into contact with SARSCoV-2 again at a later stage, their immune system will recognize the virus and be ready to fight it. The mRNA of the vaccine does not remain in the body, but it breaks down shortly after vaccination.
4. What does it contain?
The COVID-19 mRNA BNT162b2 (Comirnaty) contains a messenger RNA that cannot propagate itself in host cells, but induces the synthesis of antigens from the SARS-CoV-2 virus (which it encodes by itself). The S antigens of the virus stimulate the antibody response of the vaccinated person with the production of neutralizing antibodies. Messenger RNA is encapsulated in liposomes made up of ALC-0315 and ALC-0159 to facilitate entry into cells. The vaccine also contains other components: • 1,2-Distearoyl-sn-glycero-3-phosphocholine • cholesterol • dibasic sodium phosphate dihydrate • monobasic potassium phosphate • potassium chloride • sodium chloride • sucrose • water for injections
Vaccination efficacy and safety
5. Was the trial shortened to get the product soon?
Studies on COVID-19 vaccines, including the COVID-19 mRNA vaccine BNT162b2 (Comirnaty), began in the spring of 2020, so they lasted a few months compared to the usual times, but had the participation of a large number of people – ten times higher than the standards of similar vaccine development studies. Therefore, it was possible to conduct a large study, sufficient to demonstrate efficacy and safety. None of the usual phases of verification of the efficacy and safety of the vaccine have been skipped: the short times that led to rapid registration have been made possible by the research carried out over many years on RNA vaccines, to the large human resources and made available in a very short time and for the evaluation of the regulatory bodies of the results obtained as they were produced and not, as usual, only when all the studies are completed. These simple steps have saved years of approval times.
6. How were the clinical studies conducted?
A very large clinical study has shown that the COVID-19 mRNA BNT162b2 vaccine (Comirnaty) is effective in preventing COVID-19 in people 16 years of age and older. The safety and efficacy profile of this vaccine was evaluated in a study conducted in six countries: the United States, Germany, Brazil, Argentina, South Africa, and Turkey, with the participation of more than 44,000 people. Half of the participants received the vaccine, the other half received a placebo, a product identical in all respects to the vaccine, but not active. Efficacy was estimated in more than 36,000 people 16 years of age and older (including those older than 75 years) who had no signs of previous infection. The study showed that the number of symptomatic COVID-19 cases was reduced by 95% in subjects who received the vaccine (8 of 18,198 cases had COVID-19 symptoms) compared to those who received placebo (162 cases). of 18,325 had symptoms of COVID-19).
7. How effective is it?
The results of these studies showed that two doses of the COVID-19 mRNA BNT162b2 vaccine (Comirnaty) administered 21 days apart can prevent 95% of adults over the age of 16 from developing COVID-19 with substantially age-homogeneous results, gender and ethnicity. The 95% reduction refers to the difference between the 162 cases that occurred in the group of more than 18,000 who received the placebo and the only 8 cases that occurred in the more than 18,000 who received the vaccine.
8. Is protection effective immediately after injection?
No, efficacy was demonstrated one week after the second dose.
9. How long does the protection induced by the vaccine last?
The duration of protection is not yet defined with certainty because the observation period was necessarily a few months, but knowledge about other types of coronavirus indicates that protection should be at least 9-12 months.
10. Can the vaccine cause COVID-19 disease or other genetic alterations?
This vaccine does not use active viruses, but only a genetic component that brings information to the vaccinator’s body to produce specific antibodies. There are no whole or live viruses involved, so the vaccine cannot cause disease. Vaccine mRNA, like all mRNA produced by cells, naturally breaks down after a few days in the person who receives it.
11. Can vaccinated people transmit the infection to other people?
The clinical studies carried out so far have made it possible to evaluate the efficacy of the COVID-19 mRNA BNT162b2 vaccine (Comirnaty) in clinically manifest forms of COVID-19, and more time is needed to obtain meaningful data to demonstrate whether vaccinated individuals can become asymptomatically infected. and infect other people. While it is plausible that vaccination protects against infection, vaccinated people and those in contact with them should continue to take protective measures against COVID-19.
12. Who administers the first dose of the COVID-19 mRNA BNT162b2 vaccine (Comirnaty)? Can you give the second dose with another Covid-19 vaccine, if available?
There is still no data on the interchangeability between different vaccines, so those who get vaccinated at the first dose with the COVID-19 mRNA vaccine BNT162b2 (Comirnaty), will continue to use the same vaccine for the second dose.
13. What adverse reactions have been observed?
The most commonly observed adverse reactions (more than 1 in 10 people) in the COVID-19 mRNA BNT162b2 vaccine study (Comirnaty) were generally mild or moderate in severity and resolved within a few days of vaccination. These included pain and swelling at the injection site, fatigue, headache, muscle and joint pain, chills, and fever. Fewer than 1 in 10 people experienced redness and nausea at the injection site. Itching at the injection site, pain in the extremities, swollen lymph nodes, difficulty falling asleep and nausea were rare and affected less than 1 in 100 people. one side of the face (acute peripheral facial paralysis) has occurred rarely, in less than 1 in 1000 people.
14. What serious adverse reactions were observed during the trial?
The only serious adverse reaction more frequent in those vaccinated than in the placebo group was enlargement of the lymph nodes. However, it is a benign disease that heals on its own. In general, systemic reactions were more frequent and pronounced after the second dose. In countries where mass administration of the vaccine has already begun, reports of adverse reactions have also begun, ranging from the least serious to the most significant, including allergic reactions. All countries that start the administration of the vaccine extended to the entire population will collect and evaluate all the reports received by the pharmacological surveillance system of adverse reactions to the vaccine, in order to be able to define with increasing precision the type of risk profile associated with it. to vaccination.
15. Who develops a reaction to management to whom can they communicate it?
The notification of any reaction to the administration of the vaccine can be made to your GP or to the ASL to which you belong, as well as all other adverse reactions. to any drug, according to the national pharmacovigilance system that has been active for some time throughout the country. Also, anyone can report an adverse reaction to the vaccine in the first person using the forms posted on the AIFA website: https://www.aifa.gov.it/content/segnalazioni-reazioni-avverse.
16. How is the absence of contraindications detected?
Before vaccination, health personnel ask the person to vaccinate a series of precise and simple questions, using a standardized form. If the healthcare provider finds meaningful answers to questions, consider whether the vaccination can be given or postponed. In addition, the operator checks the presence of contraindications or particular precautions, as also reported in the vaccine data sheet.
17. A new variant of the SARS-CoV-2 virus has been reported: will the vaccine also be effective against this new variant?
RNA viruses such as SARS-CoV-2 are subject to frequent mutations, most of which do not significantly alter the structure and components of the virus. In 2020 many variants of SARS-CoV-2 were reported, but so far these variants have not altered the natural behavior of the virus. The variant reported in England is the result of a series of protein mutations on the surface of the virus and the effects these may have on the progress of the epidemic are being evaluated, while a negative effect on vaccination seems unlikely.
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