Corona Vaccine Update
Corona Vaccine Update: The UK has become the first western country to license a vaccine against Covid-19, opening the way for mass vaccination with the Pfizer/BioNTech vaccine to begin next week for those most at risk.
The vaccine has been authorized for urgent situation use by the Medicines and Healthcare products Regulatory Authority (MHRA), before decisions by the US and Europe. The (MHRA) was put power to approve the vaccine by the government under special regulations before 1 January 2021 and when it will become fully responsible for medicines authorization in the UK after Brexit.
The first doses of the vaccine would arrive in the coming few days, said the company. The United Kingdom has bought 40m doses of the vaccine, which has been shown to have 95% useful in its final trials. All covered 19 vaccines being developed aim to produce immunity to the sar kof2 virus by stimulating an immune response to an antigen usually the characteristic spike protein found on the surface of the virus some traditional vaccines achieve this 00:21 by modifying the virus to weaken or disable it.
So that when introduced to the body an immune response can be generated to the antigen without the virus causing disease when the immune system comes into contact with the weakened virus its defenses such as antibodies and the cells attack the virus or infected cells in the process specialized memory cells take note of the specific antigen and prime the immune system to produce cells and antibodies that will quickly target these proteins so the next time that person is exposed to the same virus the immune system is ready to fight it off instead of using the whole virus another way to trigger immunity involves using just fragments of it like the spike proteins these submit vaccines have the advantage of being relatively easy and cheap to produce and are incapable of causing disease.
Because these fragments are not able to infect host cells however they are less likely to be recognized by immune cells aimed at attacking infected cells which means they may trigger a weaker immune response because of this submit vaccines often include chemical agents called adjutants which are designed to stimulate a stronger immune response and booster shots may also be required not all vaccines are designed to introduce antigens to the body some work by using cells in a patient's body to produce the antigens themselves.
Examples include viral vector vaccines and myna vaccines in both cases the goal is to get a short fragment of genetic code taken from the target pathogen in this case the sars cove virus that causes covid19 into the patient's cells by hijacking the cellular mechanisms these kinds of vaccines mimic the way viruses normally reproduce during natural infection but rather than creating copies of the virus the cells only produce large amounts of antigen that then usually trigger a strong immune response viral vector vaccines achieve this by inserting the genetic code for the antigen into a harmless virus which effectively acts like a delivery system to get the code into the cells without causing disease vector-based vaccines can be complex to develop but they can trigger strong immune responses without the need for adjutants and in theory one type of vector can be used to deliver code for a range of different antigens which can speed up vaccine development nucleic acid vaccines like mrna and dna vaccines also involve inserting genetic code into cells to produce antigens.
But instead of using viruses to deliver the code these vaccines take a more direct approach that involves inserting the code directly into cells either by attaching it to a molecule or by forcing it into cells using a gene gun these vaccines can be quick and cheap to develop but they are a relatively new technology with hundreds of covid-19 vaccines now in development it's likely that a mixture of different approaches will be needed in order to stop the global spread of this corona virus and end the pandemic.
