‘It takes 5 to 10 years to clone, sequence a virus’
Srinagar, May 11: Kashmir’s noted scientist, Dr Mohammad Sultan Khuroo, on Monday said that applying “quick fix and short cuts” to develop COVID-19 vaccine can lead to errors with disastrous consequences.
“There is an atmosphere of tremendous hype around the COVID-19 vaccine and developers are using every opportunity to make claims, which remain unverified. Applying quick fix and ‘short cuts can lead to errors with disastrous consequences,” Dr Khuroo to news agency KINS.
He said that the need of the hour is to develop an effective and safe vaccine that shall be manufactured and available to all countries and populations affected by the pandemic at an affordable price.
The Researcher further said that there has been an unprecedented fast track path taken in R&D by the World community for developing an effective and safe vaccine. “Platform technology has been exploited to develop candidate vaccines in a matter of days to weeks and as of now, 108 such vaccines are available. Six of these vaccines have entered clinical trials. As clinical trials are ‘rate-limiting’ and ‘time-consuming’, many innovative methods are in practice for a fast track. These include parallel phase I-II trials and obtaining efficacy data from phase IIb trials. Human ‘challenge experiments’ to confirm efficacy in humans is under serious consideration. The availability of the COVID-19 vaccine has become a race against time in the middle of death and devastation” he maintained.
He said that the COVID-19 has turned in to a global human tragedy and economic devastation. “Governments have implemented lockdown measures, blocked international travel, and enforced other public containment measures to mitigate the virus morbidity and mortality. As of today, no drug has the power to fight the infection and bring normalcy to the utter chaos,”
He said that the ordinarily, it has taken from 5 to 10 years to clone and sequence a virus from the time the disease is discovered. “It has taken us from 5 to 10 years in the history of vaccine development against other infectious agents to reach a stage as we are now with the COVID-19 vaccine .There has been a tremendous race against time, to develop candidate vaccine in a matter of few weeks and as of now, some candidate vaccines have entered phase I-II clinical trials. However, clinical trials as are undergoing now will be the greatest limiting factor, as these need time to acquire human data. Normally phase I, II, and III trials to be done on humans are completed between 2 to 5 years and sometimes more. This is necessary for qualifying a vaccine to be safe, immunogenic, and efficacious” Dr Khuroo maintained.
He said that as of today, candidate vaccines are undergoing phase I or parallel I-II studies and shall take several months for acquiring these data to start phase III trials. “Phase III trial once initiated can take as long as 2 years. To compress the period vaccine developers are involved in adopting parallel and adaptive development phases (I-II) to acquire safety and immunogenicity data as soon as possible to initiate phase III trials. By any imagination, these data shall not be available by early 2021 for any vaccine for regulatory authorities to allow vaccine marketing. COVID-19 Vaccines could be available for human use earlier if innovative methods of clinical trials and regulatory processes are employed. One such is the use of ‘Challenge studies’ to testify vaccine efficacy. Here, following proof of safety and immunogenicity in phase I-II trials, controlled ‘challenge studies’ which can be completed in a matter of weeks, are done to confirm vaccine efficacy” the doctor said.
He said that challenge studies have been done in the past in other infectious diseases namely influenza, typhoid fever, cholera, and malaria. “Whether ‘challenge studies’ are ethical in COVID-19, considering the risk to the volunteer is a matter of debate before the vaccine developers (70). Also, regularity authorities can use innovative procedures to allow guarded emergency use of a vaccine. This would need careful consideration of interventional animal safety data and data of safety, immunogenicity, and efficacy acquired from phase I-II trials. With all this, vaccine developers have to be ready to scale manufacturing capacity to massive demands once the product is allowed for marketing”.
What regulators have to worry about is the atmosphere of hype about the COVID-19 vaccine? “Public claims about breakthrough research based on poorly conducted studies or data collected through fraud is a real possibility. All data which form the basis of any findings need to be scrutinized and should be confirmed by other investigators. Relaxed on regulatory principles based on political pressure and goodwill needs to be resisted” he said.
He added that a clear example was seen when the FDA in the US and ICMR in India allowed the use of hydroxychloroquine without convincing data about the efficacy of the drug. “Vaccine developers in the R&D process are in a race to generate data from human trials. One must use a stringent guard to protect the interests and safety of those volunteers who are a part of such experiments. Lastly, vaccine development is a risky process, and one critical issue in the COVID-19 vaccine would-be the occurrence of ‘Antibody-Dependent Enhancement (ADE)’ which may be disastrous for those receiving the vaccine. Regulators have to take all precautions to discourage candidate vaccines which may show such a phenomenon”. (KINS)