Lauryn Mitchell discusses the vaccine candidates that have recently emerged
COVID-19 has put the world on pause, causing international lockdowns, millions of deaths and the virus is not backing down. But hope does dawn, and there have been many successful trials for potential vaccines happening all over the world.
There have been many successful trials… happening all over the world
The vaccine which has caught all of our attention is the Pfizer vaccine, which has an over 90% success rate in early phase III trials. This works by injecting mRNA (which is a vital part of protein production in all cells) into the subject whose own cells will then go on to make the COVID-19 spike proteins. The patient’s immune system will then flag these proteins as foreign particles and create antibodies targeted to COVID-19. If the virus then infects the vaccinated individual, the antibodies will kill it before damage is caused.
This is really good news in the development of a vaccine, but what are some of the other vaccines that are currently being trialled, and how hopeful are they?
An important contender is the Oxford vaccine (or AZD1222). This vaccine- which is being co-developed with the pharmaceutical company AstraZeneca- is based upon a different virus (causing the common cold in chimpanzees) which has been modified to cause no symptoms in patients. The virus cells have been altered to carry the spike proteins of COVID-19, causing the patient’s cells to create antibodies against COVID-19 and kill it if the patient is infected. So far, trials have shown that this vaccine has prevented 70% of patients from developing symptoms of COVID-19. Although this vaccine is less successful than the Pfizer vaccine, it is cheaper and easier to store, therefore more available worldwide.
The US company Novavax have also been doing trials on their potential vaccine which is currently undergoing the third phase of testing and is being trialled on human subjects. This vaccine consists of recombinant nanoparticles containing the engineered spike proteins of COVID-19. This again causes the subject’s ells to produce antibodies against COVID-19. The Novavax vaccine has so far been successful in trials using rhesus monkeys, who after injection of the vaccine produced antibodies against COVID-19. The vaccine is still undergoing human trials, but has shown promising results so far.
The last vaccine to be secured by the UK government is the Valneva vaccine whole virus, Vero cell “VLA2001” vaccine. This vaccine contains a whole virus cell which has been inactivated- meaning that it will not cause symptoms of COVID-19 in patients. The vaccine is expected to enter clinical studies by the end of this year. This method has been used to create other successful vaccines for decades.
[The VLA2001 vaccine] is expected to enter clinical studies by the end of this year
So, with the many ongoing rigorous trails happening right now, scientists believe it is almost definite that we will have a vaccine against COVID-19 in 2021. For now, we must all abide by the governments guidelines to keep the number of cases to a minimum and to keep us and everyone around us safe.