This paper explores the trends, issues and challenges confronting the successful vaccine development for the novel Coronavirus disease. Right from the starting of COVID-19 pandemic, no drugs or vaccine has been developed nor approved for treating those with coronavirus infection. This year the scientific community and the vaccine industry have been asked to respond urgently to this pandemic. Presently numerous vaccine development platforms are under the process for DNA and RNA based vaccines showing great potential followed by recombinant- subunit vaccines. Through explorative research, it was established that the companies involved in COVID-19 vaccine development are facing big challenges in the scientific, economic and logistic perspectives. Among these challenges understanding the immune system interaction with the vaccine being developed, as well as with the pathogen itself. The race is going on and progresses are being made. Proper understanding of trends and dynamics revolving around COVID-19 vaccine is crucial in expanding possibilities for positive results from ongoing research. In this context the focus is on the recent development in COVID-19 vaccines.
COVID-19 vaccine development is an undergoing operation with the aim to develop drugs for prevention and treatment that would mitigate the intensity of Corona virus disease. To develop safe and efficacious vaccine several Pharmaceutical, biotechnological companies, research institutes and various health organisations have come together to assess different treatment strategies for COVID-19 disease in various stages of pre-clinical and clinical research.
The conventional drug development process takes many years of research however this process is not feasible in the current scenario of the pandemic therefore clinical studies for already existing drugs are being explored for vaccine development such as convalescent plasma, interferon based therapies, small drug molecules ,monoclonal antibodies, ACE-2 receptor blockers, NSAIDs , antiviral drugs and some antibiotics.
WHO has introduced a solidarity trial for an effective treatment of COVID-19 and this trial assess the effect of drugs on 3 parameters that is: mortality, need for assisted ventilation and duration of hospital stay. During clinical research the solidarity trials aims to evaluate whether any of the drug is escalating survival rates or lowering the need for ventilation or hospital stay.
BRIEFING OF DIFFERENT PHASES OF CLINICAL TRIALS:
- PHASE-1-The initial phase of testing, includes a small number of healthy volunteers(20-100), the aim here is to determine the effects of drug in humans and to know how it is absorbed, metabolised, and excreted. Side effects that occur because of the drug are also determined in this phase.
- PHASE-2 – This phase studies about the efficacy of a drug and involves up to several hundred patients. This phase aims to obtain data on whether the drug is showing any effect in people who have a certain disease at selected doses.
- For controlled trials, patients receiving the drug are compared with similar patients receiving a different treatment usually placebo, or a different drug.
- PHASE-3 – This phase study begins if confirmation of effectiveness is shown in phase-2. In this phase more details are gathered about well-being and efficacy, by studying divergent populations and contrasting dosages and employing the drug in combination with other dosage form.
- The number of individuals involved in this phase normally ranges from several hundreds to about 3000 people.
- PHASE-4 – Often called as Post Marketing Surveillance and it is conducted after a drug has been accepted for consumer sales.
CLINICAL TRIALS CONDUCTED BY DIFFERENT PHARMACEUTICAL COMPANIES:
- Pfizer and BioNTech
- Type: mRNA vaccine
- Stage: phase 2/3
- Name: BNT162 program
Mechanism of Action- The main function of RNA vaccines is quite normal just like other vaccines that is the production of antibodies which will further bind to potential pathogens. RNA sequence codes for antigens and proteins and upon delivery of the vaccine into the body this sequence gets translated by host cells to produce encoded antigens and stimulate the body’s immune system to produce antibodies.
Adverse Effects- The mRNA strand may show some unintended immune reactions. Therefor identification of individuals who are at increased risk of the immune reaction before mRNA vaccination is very important so that precautions can be taken. It obtained an emergency-use authorization from the Food and Drug Administration in the U.S based on clinical trials, one was regulated by NIAD (National institute of Allergy and Infectious disease) and one by Gilead
Patients taking this drug had median recovery time of 11 days as compared to patients taking placebo showed recovery time of 16 days Mechanism of Action- Remdesivir has the ability to metabolise into an active form known as GS- 441524 which is an adenosine nucleotide analog. This active form of remdesivir interferes with the action of viral RNA – dependent RNA polymerase due to which viral RNA production decreases.
The process of modelling vaccines research and development is split into three stages, (i) modelling clinical trials until their approval, (ii) modelling the time it takes to scale up manufacturing, and (iii) modelling capacity to predict how long it will take to produce significant volumes of new vaccines.
There are many candidates against COVID-19, and many manufacturing facilities across the world that are capable of producing vaccines. Research is being continued at a very high speed. To provide a practical and realistic framework for data collection, vaccines are categorized into different “platforms.” These platforms range from more traditional and established methods—such as an inactivated viral vaccine, where virus particles with no ability to produce disease are used to stimulate an immune response—to newer technologies including DNA and RNA vaccines which produce an immune response without viral particles.
R&D and clinical trials
To estimate how long it will take to manufacture enough vaccines, we must first know which vaccines need to be manufactured. We also should know about the funding for vaccine candidates, and after the completion of clinical trials the success and failure of vaccines that are being manufactured can be determined. The results of an individual run will not tell us a lot about the vaccine portfolio, by aggregating the results we should get a sense of both timelines and numbers of vaccines that could be approved.
Manufacturing and implementation
This part of the model aims to estimate the time required after a vaccine has been approved before commercial manufacture can begin. A drug substance that has been manufactured for early stage clinical trials is most often at “R&D scale,” produced in facilities with lab or small-scale equipment to supply doses in the thousands. Scaling up manufacturing to commercial scale adds complexity. Therefore, any attempt at commercial manufacture in the order of millions or billions of doses needs to consider the steps to scale up the process and adapt it for manufacture at a given location; under normal circumstances, this could take a few years.
The transition from R&D to manufacturing is typically carried out by a large multifunctional team and includes process development activities, design and construction activities, and quality assurance/regulatory activities.
Strict regulations to ensure that manufacturing processes and plants meet current good manufacturing practice (CGMP) guidelines also add time to the transition from R&D to commercial manufacturing. The plant and equipment must be qualified, and processes shown to be safe and effective and licensed by regulators from all the jurisdictions where the vaccine will be used. Data for the product, process, and plant must be submitted to regulators in every jurisdiction where the vaccine will be used, and regulators vary in their requirements and, often, their areas of focus. Regulators can ask for clarifications or improvements, sometimes requiring additional data to be generated or even modifications to plant or process. In addition to manufacturing capacity, such a large scale-up also requires sufficient quantities of auxiliary supplies, such as vials (or other primary containers), adjuvants, and in some cases, single-use bioreactors.
The overall sequence is well-understood, but there are many factors—such as type of vaccine and dosage form, manufacturing location, and supply markets—that affect how long each step takes. Through industry expert input, we are developing an initial model to represent each key stage of a vaccine’s journey from success in clinical trials to commercial manufacturing. The model incorporates possibilities that capacity already exists at sites, that existing capacity requires modification, or a new factory is required. This includes all steps of “qualification”—validation and testing processes that ensure equipment has been installed correctly and will perform as expected under real factory conditions.
The primary output from the overall model is an understanding of when global vaccine demand—defined here by the WHO targets—may be met. It is intended to collect global manufacturing capability for primary (manufacture of the active ingredient, for instance virus or mRNA) and secondary (manufacture of the dose form, for instance a vial of a liquid solution of the active ingredient) manufacturing, which would be used to build a picture of currently available capacity and potential future capacity for the suite of vaccine platforms and technologies.
Outputs from the R&D model are used a starting point, indicating when individual vaccine candidates may pass clinical trials—using a defined point in time as a reference point. Each successful vaccine will then pass through the manufacturing implementation model to determine a timeline for start of primary and secondary manufacture. Vaccines can then be allocated to available network capacity for the appropriate platform, computing the monthly dose production and cumulative dose count not only as a total, but also for each vaccine individually. This level of detail may be important given the possibility that different vaccines can be used for different populations (age ranges, for example) based on the level of immune response elicited. In comparing these production figures with the WHO targets, the time from the reference point to production milestones can be estimated.
The journey for COVID-19 vaccine development began several months ago. The progress for the development of vaccine is taking new turns overtime. The role of stakeholders or collaborators is prime for ensuring success in the long run. However, there is a need for a deeper understanding of practical and real time issues that are required in the development of vaccine. Particularly, there is a need to know the complex challenges related to vaccine hesitancy. To prevent the challenges continuous efforts on the part of all stakeholders – healthcare professionals, government, civil society and the general public cannot be overemphasized. Especially in the area of making explanations on what is not known and what needs to be known regarding vaccines along with the risks and benefits as well as their understanding to communities and individuals is highly essential. As the coronavirus disease continues to devastate the world featuring stigma, suspicion, fear and the worst of it all death the development of COVID-19 is still on field to play.