On July 20, Oxford University published the result of the first human trials of their Covid-19 vaccine, raising the hope for the availability of the vaccine for public inoculation before the coming Christmas.
The vaccine is being developed jointly by the Oxford University Jenner Institute and the Oxford University Vaccine Group, led by Professor Sarah Gilbert, and supported by the UK government promising to provide every possible resource the team would require to successfully develop the vaccine.
In his own words, the health secretary of the British government said to “back them to the hilt” and has provided millions in pound sterling in cash support. The vaccine’s phase one clinical trial started on April 23 on volunteer healthy adults aged between 18-55 years, with a funding of nearly £22 million to ensure the most comprehensive data tests on the trial population.
According to Professor Pollard, the chief investigator of the project, a million vaccines would be produced for inoculation by the end of summer and beginning of autumn, by September this year, and a potential large-scale production capacity is already planned at risk to be in place, indicating that the large-scale vaccine would be manufactured at risk of being ineffective and destroyed if trials fail to demonstrate the vaccine’s efficacy.
According to Professor Adrian Hill, the director of the Jenner Institute, University of Oxford, revealed that the vaccine, if proven successful, would herald the manufacture of hundreds of millions of doses so that global immunization could be ensured by the end of the year 2020 to successfully end the pandemic.
It is claimed that the British team led by Oxford Group are the furthest ahead of the first 23 in the grid racing to develop a vaccine against this deadly virus that has already claimed more six hundred thousand human lives, and the number continues to grow every day.
The Oxford Group has been firmly confident, from the very start, about the success of the development of their vaccine and their confidence has been built on their past experience of success. The group uses its earlier developed vaccine manufacturing platform (Vax Hub), the result of the collaborative effort of the UK Engineering and Physical Sciences Research Council, University College London, and the University of Oxford.
They had used the same vaccine technology on other similar viral diseases, including the related coronavirus MERS (Middle-East Respiratory Syndrome) and, as recently as 2014, the team had exceptional success in rapid vaccine invention-response to the Ebola outbreak in West Africa.
The basic structure of the SARS-CoV-2 virus comprises a spherical envelope with the virus, a single-stranded RNA inside. The envelope bears club-shaped projections, the spike glycoprotein. The virus arrives at the human cell of the throat and the airways through the mouth, nose, and the eyes, and like a space shuttle docks itself on the receptor sites of the cells in our throat and airways below.
Normally, the human cells would not allow entry of the virus inside, but once docked on the human cell, the spike glycoprotein works to weaken the cell wall and facilitates the entry of the virus inside our cells. Soon, the virus enters our cells, multiplies exponentially, and converts the entirety of the airways and lungs into a massive production factory.
However, though the virus infects an individual, it does not cause symptoms initially; later, it may declare its presence subtly with very mild non-specific symptoms of cough and fever. Even though there is no symptom or mild and vague symptoms, the virus is being shed continuously through coughing, sneezing, and spitting, infecting other human victims.
The Oxford vaccine “ChAdOx1 nCoV-19” is a recombinant vaccine, the inner core or template is a modified adenovirus causing common cold in chimpanzees. It is modified in such a way that even if it enters a human cell it is incapable of replicating, and thus not capable of infecting humans. The second component of the vaccine is a genetically modified spike glycoprotein capable of initiating and launching a human immune response and generating antibody production, but not capable of any major harm to our body.
The vaccine received approval for trial towards the end of March and Phase 1 clinical trial started on April 23 in healthy young volunteers aged between 18-55. Before the clinical trial began, the vaccine was given to more than 320 people and had been shown to be safe and well tolerated, although they may cause temporary side effects, such as a temperature, headache or sore arm.
The vaccine is already in production. Given the devastation unleashed by the virus, the immediate start of large-scale manufacturing following rigorous safety standards guarantees the availability of high quality, safe vaccines when approved for use.
The Oxford Vaccine preclinical trial was also held at the US National Institute of Health’s Rocky Mountain Laboratory in Montana on rhesus monkeys. Rhesus macaques have the closest and most similar immune system to humans. The result demonstrated that a single dose of the vaccine was effective in protecting monkeys from developing Covid-19 when exposed to large quantities of the virus.
The full result of the Phase I trial has just been published in the Lancet Medical Journal. 1,077 healthy volunteers were recruited from 5 hospitals across the UK from April 23 until May 21. The recruited volunteers either received the Covid-19 vaccine or a safe meningitis vaccine; one of the groups injected with Covid-19 vaccine also had a booster after 28 days.
The compelling results have demonstrated the vaccine to be safe, causing no serious adverse reactions. The side-effects: Pain at the injection site, flu-like symptoms of feeling feverish or a high fever, muscle aches, chills, malaise, or fatigue and headaches, responded in most cases to simple paracetamol.
Response to any vaccine can follow two pathways, a T-cell response and an antibody response. When the vaccine was administered, volunteers immediately started to grow T-cells that peaked at day 14, and neutralizing antibodies were seen in 91% of volunteers 28 days after vaccination.
The group who received a booster dose on day 28 had a much greater immune response. Over 10,000 people have been vaccinated with the Oxford vaccine to demonstrate if the vaccine prevents Covid-19 and if despite vaccination anyone develops Covid-19, whether the vaccination would prevent severe illness.
However, we are constantly reminded of the uncertainty fraught with the novel coronavirus. As humanity basks in the hope of developing a safe and effective vaccine against the novel coronavirus, known as SARS-COV-2, Professor Loman of the University of Birmingham and of the Covid-19 Genomics Consortium declared a new mutation of the Covid-19 that has become the dominant strand of the novel coronavirus globally and presently accounts for about three-quarters of the cases of all infections.
This strand forms clusters of infection more quickly and aids outbreaks spread more rapidly, mainly increasing transmissibility. Luckily, the mutation is only confined to transmissibility and does not in any other way affect Covid-19 severity and fatality. This mutation is confined to the spike protein of the virus, the Trojan horse, that attaches to human cells, ensuring access of the virus inside the cells -- thus the mutation has increased the ability of the virus to gain increasing access.
The SARS-CoV-2 virus was extremely efficient at infecting people. However, the viral transmission of the Wuhan variety before this mutation was relatively slow. Though this mutation is not going to have any impact on our quest for a vaccine, the nature of the exceptional mutating capability of the virus constantly reminds us of our limitations and vulnerability.
Then again, two drugs, Interferon-beta (INF-beta) and Dexamethasone, have been proven to be effective in Covid-19. Dexamethasone reduced fatality by up to a third in severely ill patients requiring oxygen or ventilation. In the case of INF-beta, demonstration of the odds of developing severe disease requiring ventilation or resulting in death during the treatment period, were significantly reduced by 79% for patients receiving it.
These two drugs, and the possibility of the availability of a safe and effective vaccine soon must boost our optimism in these dark days.
Dr Raqibul Mohammad Anwar is Specialist Surgeon and Global Health Policy and Planning Expert, and Retired Colonel, Royal Army Medical Corps, UK Armed Forces.
