Coronavirus: 'Quick vaccine for COVID-19 impossible,' say medical experts
Global health experts break down the various steps and stages of the research that goes into any vaccine, while advocating caution
Medical experts say the vaccine for COVID-19 is far from reality, as the shortest duration taken for any vaccine to be developed was for mumps, which took nearly four years of research. On an average, vaccines take five to 10 years to develop and in many cases, even more years. They feel the development of a vaccine to tackle a new virus, such as the novel Coronavirus in a short time, is humanly impossible.
Dr Subhash Hira, Professor of Global Health at the University of Washington and former Technical Advisor to Ministry of Health, New Delhi was invited to attend the virtual 'Global COVID-19 Research & Innovation Forum July 1-2, held in Geneva, while Dr Tedros Adhanom, Director General, WHO was in attendance. This meeting did a critical review of research findings so far and their impact on the response to COVID-19, and progress of several vaccine studies underway in the world.
Dr Wiqar Shaikh, Dr Ketan Vagholkar and Dr Subhash Hira
Asked about chances of a COVID-19 vaccine ready for use by mid-August 2020, Professor Hira said, "Such short timelines are difficult to meet in the field of biology, but they certainly show a positive connotation of national determination towards self-reliance in the fields of science and health."
Dr Hira added that so far, there were some precedences in science, whereby once vaccine efficacy is established, the world does not wait for findings about immunity and neutralising antibodies. A classical case he cited was of the Hepatitis B vaccine that was introduced for human use in 1986 after 20 years of research wherein immunity markers remained unresolved. It took another 20 years after the use of the Hepatitis B vaccine that its neutralising antibodies and immunity questions became evident to the scientific world.
'Only solution is herd immunity'
Dr Wiqar Shaikh, senior asthma and allergy specialist, added, "It is unrealistic to expect a fullly effective vaccine for at least two years or may be never at all. In the absence of a vaccine for COVID-19, the only solution for this pandemic is the development of herd immunity. In the history of medicine, no vaccine has been developed in less than five years and it generally may require 10 years or more of research. The record for the fastest developed vaccine, is the mumps vaccine, which was developed in a record four years, between 1963 and 1967."
Interestingly, enough reports reveal that the Oxford vaccine for COVID-19 has failed the preclinical test in animals. When swabs of monkeys were tested for presence of SARS-Cov2, there was no significant difference between vaccinated and unvaccinated monkeys. If therefore, the vaccine works the same way in humans, vaccinated individuals will continue to be active spreaders of COVID-19.
Until July 2020, 218 vaccine candidates globally were in various stages of development. Of these, only 24 are undergoing clinical trial, Dr Shaikh added.
'Hasty development is dangerous'
"The current pandemic, and the need to stop it should not lead to hasty development of a vaccine without adequate positive scientific studies. Commercial and economic greed cannot override, established scientific principles. Cutting corners and attempting to drastically shorten the stages of vaccine development could be dangerous to human life. A classic example is the dengue vaccine (Dengvaxia). In November 2017, a vaccine against dengue was announced in the Philippines. After the vaccine was administered to children during human trials, over 600 of them died, because of complications from it. While the vaccine had taken 20 years to be developed and cost $1.5 billion, the Dengvaxia disaster could be repeated by a half-baked, hastily developed vaccine for SARS-Cov2," Dr Shaikh said.
He said it was shocking that despite the failed animal experiment, the Oxford vaccine was allowed to proceed to the stage of human trials. "How is it possible that almost all vaccine makers claim they will be developing one within this year? The lead researcher, Sarah Gilbert of the Oxford vaccine, has admitted in the media, that its trials are expected to continue till August 2021. The WHO has clearly mentioned that one cannot expect a COVID-19 vaccine before 2021," Dr Shaikh added.
He further stated, "Despite several years of research we have not yet developed, a safe and effective vaccine for other viruses like dengue, SARS-Cov1, MERS (Middle East Respiratory Syndrome), Swine Flu (H1N1), Ebola Virus, HIV (AIDS), which itself explain that it is humanly impossible to have a vaccine for SARS-Cov2 within six months of the pandemic outbreak."
An effective vaccine for SARS-Cov2 should stimulate the immune system to first produce antibodies, and more importantly, to produce memory T cells (they have immunological memory), exactly like a person, who is exposed to the disease. After getting vaccinated, an individual should develop complete immunity to SARS-Cov2, without ever contracting the disease.
Dr Ketan Vagholkar, professor of surgery at D Y Patil Medical College said, "The initial result of development of a vaccine for SARS-CoV-2 is undoubtedly the silver lining of the cloud. However, it is unnecessarily developing euphoria amongst the various countries affected by COVID-19. Elaborate trials need to be further conducted, in order to assess efficacy, side effects and duration of protection offered to the recipient."
Dr Vagholkar added, "This will take at least a year, even more, for the final results to be declared, until then, basic principles of self-protection and early reporting to hospitals in case of symptomatic patients, continues to be the mainstay of treatment. All affected nations are looking eagerly forward to this vaccine. Therefore, speculating any dates, before a year, would be unwise and would surely disappoint the general population."
Stages of vaccine development
According to Dr Wiqar Shaikh, There are six stages of vaccine development – exploratory stage, pre-clinical stage, stage of clinical development, regulatory review and approval, manufacturing of vaccine and quality control. Medical science is mainly involved in the first three stages. Stage 1 requires basic laboratory research for the proposed candidate vaccine, which often lasts for two to four years. In this stage scientists identify natural or synthetic antigens, which might help prevent or treat a disease.
The second stage of pre-clinical stage involves animal testing to assess the safety of the vaccine and its ability to induce a robust immune response. But the majority of candidate vaccines do not progress beyond this stage, because they fail to produce the desired immune response. Pre-clinical stage often last for one to two years.
The third stage of clinical development has three phases- phase 1 involves small groups of people around 20 to 30 individuals, phase two involve large groups of individuals in several hundreds and phase three involves thousands of individuals. Development of vaccines requires successful phase 1 to phase 2 progress and successful phase 2 to phase 3 progress.
"The goals of these phases are to determine the type and extent of the immune response provoked by the vaccine, its safety in human beings, dose, schedule of administration and method of delivery. Only when all these stages and phases of vaccine development are successful that we could progress to licensing and manufacturing of the vaccine along with quality control," explained Dr Shaikh.
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