Covid-19 Vaccine: How Pfizer’s Unusual Approach Works



The announcement that the Pfizer / BioNTech vaccine seems to be offering 90% efficacy in preventing new coronavirus infection went around the world on Monday and was hailed by governments as a milestone in the fight against the current pandemic. BNT162b2, is the first to show such encouraging results – although Phase 3 clinical trials have not yet been completed. Thanks to large investments from the US and other countries, Pfizer began mass production of the vaccine before it was even confirmed safe and effective. The European Union has thus secured 200 million doses, which is enough to vaccinate 100 million Europeans. But beyond the emerging first, BNT162b2 is special for another reason: it will probably be the first RNA vaccine approved. for human use. So let’s see how this relatively new technology works. Genetic instructionsAll Vaccines are designed to train the immune system to produce antibodies that attack specific molecular portions of a virus or microbe. Target molecules are called antigens. Unlike conventional vaccines, which contain parts of the pathogen itself, the Pfizer / BioNtech vaccine does not contain any antigens. It contains only mRNA molecules (messenger RNA) in which instructions for the synthesis of proteins that function as antigens. Vaccination essentially forces human cells to produce SARS-CoV-2 coronavirus proteins, which are then recognized by the immune system to make antibodies. The mRNA is introduced into the human body packaged in protective vesicles called “lipid” vesicles. It then enters the cells and translates in the same way that any other gene translates to produce the corresponding protein. BioNTech, based in Mainz, Germany, was founded in 2008 with the ambition to develop anti-cancer immunotherapies based on mRNA technology. Such treatments have not yet been approved, but the Covid-19 pneumonia pandemic has opened up new perspectives for the small German company. A great advantage of RNA vaccines is that they do not require pathogen culture and antigen isolation, which significantly speeds up the process. Theoretically, an RNA vaccine designed for a disease can be easily modified to prevent a different, unrelated infection: all that is needed is the synthesis of a new mRNA molecule with instructions for the synthesis of a new antigen. This advantage allowed BioNTech to develop a total of 20 candidate vaccines for Covid-19, four of which are being tested in clinical trials. To date, RNA technology has only been used for veterinary vaccines. The major drawback The BioNTech approach has allowed the development of candidate vaccines in record time, but it also has a significant drawback. RNA molecules are sensitive and the vaccine must be kept frozen at -80 degrees Celsius from factory to use. Freezers that reach such low temperatures are rare in developing countries and even in some developed ones. In Germany, the government plans to set up vaccination centers with deep-frozen equipment for the first round of vaccinations. However, BioNtech CEO Ugur Sahin has stated that his company is considering whether the vaccine can be stored for up to five days at 4 p.m. degrees Celsius, which would greatly simplify mass vaccination. Follow it on Google News and be the first to know all the news See all the latest News from Greece and the World, at



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