Oxford COVID-19 Vaccine Up To 90% Effective
A third candidate in the Covid-19 Vaccine Race has shown some promising results lately in the laboratory tests.
The latest candidate in the Covid-19 vaccine is AstraZeneca developed at the University of Oxford, London. The contemporary vaccine is believed to be around 70% effective in preventing Covid-19. And if it is given at a specific dose, it is believed to prevent the transmission of virus at 90% effectiveness. As stated in a press release on Monday 23rd Nov.
The latest coronavirus vaccine emerged soon after the announcements were made for Pfizer and Moderna-the previous 2 Covid-19 vaccines. Both of them were considered around 95% effective. Although AstraZeneca slightly lacks in effectiveness, yet it is cheaper than its predecessors and easier to transport as well.
This vaccine is invented by the University of Oxford and AstraZeneca. It was subjected to the infectees in 2 doses with a span of 28 days. The initial results were based on 131 test in the late-stage trials who developed Covid-19 symptoms after subjected to the Oxford Vaccine or a Placebo.
According to the statement passed by AstraZeneca – no serious safety issues were reported in the participants and non of them were hospitalized for the infection they received from the Covid-19 Vaccine. The trials were also halted for a little period when 2 of the participants developed neurological symptoms. However, the trials resumed shortly after the investigators didn’t find any link between the Vaccine and the symptoms – says Vox.
It is revealed that the dosing made a significant difference in the efficacy of the vaccine. Those who recieved 2 full dosses, the vaccine was around 62% effective. While those who received half initial dose and a complete 2nd dose were 90% effective. The press release did not include critical data about whom among the participants received the vaccine and who received placebo. The data is yet to be peer-reviewed and released by Oxford and AstraZeneca. This data could be crucial in revealing more facts based on the trends found among the participants.
An important point was raised by Mr. Mene Pangalos – the head of AstraZeneca non-oncology research and development when he told Reuters that the half dose wasn’t deliberate. Initially in the spring, the researchers found that the participants were developing milder side effects than expected. It comes out as if “they had underpredicted the dose of the vaccine by half,” Pangalos said. Soon after that, the company decided to stay with a half dose.
It’s still unclear why an accidental lower initial dose led to better results.
Dr. Andrew Pollard – the director of the Oxford Vaccine Group pointed in a media talk on Monday, according to the Belfast Telegraph – “We think that by giving a smaller first dose, that we’re priming the immune system differently — we’re setting it up better to respond,”. He further added, “And what we don’t know at this moment is whether that difference is in the quality or the quantity of the immune response.”
The general perception among practitioners is, the higher the dose the better the immune response, says Pollard. But the case is slightly different with Oxford University’s Covid-19 Vaccine, it is believed that the first dose primes the immune response and the second one boosts it. “The different ways in which you prime are known to influence the response to the booster,” he added.
The efficacy and safety data from phase 3 trials will be submitted by AstraZeneca to the regulatory authorities worldwide. Oxford University will also submit a complete analysis to an independent peer-reviewed journal. The phase 3 trials are underway in different countries across the world including the UK, Brazil, South Africa, and the US.
This vaccine works differently from Pfizer and Moderna vaccines. In those 2 vaccines, the technology that has been used makes use of a genetic messenger that prompts the Immune System to build Covid-19 spike protein. This spike prompts the immune system to create a pool of cells to attack the virus if the subject is naturally exposed.
However, the Oxford University vaccine uses a more traditional approach. It is made from a common cold virus, known as adenovirus which infects Chimpanzees. Don’t be scared, the virus has been genetically altered so that it should not replicate in humans. It includes genes in its code for Covid-19 spike protein. It helps in training the immune system to recognize the spike protein and consequently attack the virus if the subject is naturally exposed.
How is Oxford University’s Covid-19 Vaccine better than previous ones?
Although the Oxford Vaccine is less slightly less effective in the lab results than its predecessor, it, however, assumes some advantages as well. For instance, this vaccine is cheaper (per dose) as compared to its competitors. Also, it can be stored in normale refrigerator’s temperature i.e. 35.6 to 46.4 Degrees Fahrenheit. As compared to that, the Pfizer’s vaccine has to be stored in ultra-cold conditions that would likely place hurdles in its way of storage and distribution. Live Science has already reported these issues.
“Because the vaccine can be stored at fridge temperatures, it can be distributed around the world using the normal immunization distribution system,” Pollard said. “And so our goal … to make sure that we have a vaccine that was accessible everywhere, I think we’ve actually managed to do that.”
– HiTrueCare Report on the latest Covid-19 Vaccine by Oxford University and AstraZeneca – Nov 24, 2020.