Pfizer covid vaccine<br />How it works<br />mRNA vaccines teach our cells how to make a protein that will trigger an immune response without using the live virus that causes COVID-19. Once triggered, our body then makes antibodies. These antibodies help us fight the infection if the real virus does enter our body in the future.<br />‘RNA’ stands for ribonucleic acid, which is a molecule that provides cells with instructions for making proteins. Messenger RNA (mRNA) vaccines contain the genetic instructions for making the SARS-CoV-2 spike protein, which is found on the surface of the virus that causes COVID-19.<br />When a person is given the vaccine, their cells will read the genetic instructions like a recipe and produce the spike protein. After the protein piece is made, the cell breaks down the instructions and gets rid of them.<br />The cell then displays the protein piece on its surface. Our immune system recognizes that the protein doesn’t belong there and begins building an immune response and making antibodies.<br />How it’s given<br />The vaccine is given by an injection (0.3 mL) into the muscle of the arm. For the vaccine to work best, you need to get 2 doses: a single dose and then a second dose 21 days later.<br />Immunity develops over time. It takes about 2 weeks to develop significant protection against COVID-19. For the greatest protection, you will need the second dose.<br />Based on studies in about 44,000 participants, the Pfizer-BioNTech COVID-19 vaccine was 95% effective in preventing COVID-19 beginning 1 week after the second dose.<br />Possible side effects<br />In general, the side effects observed during the clinical trials are similar to what you might have with other vaccines.<br />The side effects that followed vaccine administration in clinical trials were mild or moderate. They included things like pain at the site of injection, body chills, feeling tired and feeling feverish.<br />These are common side effects of vaccines and do not pose a risk to health.<br />As with all vaccines, there’s a chance that there will be a serious side effect, but these are rare. A serious side effect might be something like an allergic reaction. Speak with your health professional about any serious allergies or other health conditions you may have before you receive this vaccine.<br />Health Canada has conducted a rigorous scientific review of the available medical evidence to assess the safety of the Pfizer-BioNTech COVID-19 vaccine. No major safety concerns have been identified in the data that we reviewed.<br />