Precision Medicine for Vaccine Development
By Elyse Harris
An alternative to the “one-size-fits-all” approach to vaccine development is the use of a “precision medicine” strategy. Precision medicine is based on the observation that patients respond differently to medicines and can have different genetic drivers for a given disease. Precision medicine uses a personalized and outcomes-based approach to address these differences by tailoring treatments to the individual patient and to their specific disease. Thus, vaccines and treatments developed with this approach could protect specific individuals as well as distinct populations, such as the elderly, who face the most severe consequences from diseases like COVID-19. As we have seen with COVID-19, certain subpopulations differ in their susceptibility and their response to specific treatments. This illustrates the potential benefits and significance of a precision-based medicine approach for vaccine development and highlights the inefficiency of the one-size-fits-all approach. Using this method, thousands of lives could potentially be saved even after a vaccine for COVID-19 is developed using conventional processes.
By categorizing people into different groups based on their clinical and molecular information, such as genetic susceptibilities, age, and gender, differentiated treatments can target each group; thus, providing treatments to patients who are most likely to benefit from them. Additionally, dosages can be adjusted more accurately, potentially reducing adverse side effects and toxicity while increasing efficacy and patient quality of life. Using precision medicine will reduce costs of drug development by ruling out therapies that likely will fail in a subpopulation, thereby avoiding unnecessary clinical testing. In order to do this effectively, precision medicine researchers collect and study individual specific information of thousands of patients to understand the subgroups of diseases. [Figure 1]
Figure 1: Precision medicine to target different groups in society
Biomarkers are measurable characteristics that indicate biological and pathogenic processes as well as pharmacological responses to a therapeutic intervention. They can be used to genetically distinguish patients and to categorize them into subgroups based on their potential response to a given treatment. By identifying a patient’s biomarkers, clinicians and scientists can measure the effects of drugs on people during clinical trials. Having one or more informative biomarkers can help in determining the success rate and safety of a drug candidate earlier in the development process.
While the use of biomarkers in research has only recently been adopted, SARS-CoV-2 biomarkers have been identified that help with the categorization of subpopulations and the development of more effective vaccines and treatments. COVID-19 biomarkers are those that correlate with the severity of the disease and include inflammatory biomarkers such as IL-6, C-reactive protein, and procalcitonin, which were significantly higher in patients experiencing severe reactions to the SARS-CoV-2 compared to mild cases. Among the first cells to respond to COVID-19 are T-lymphocytes, and decrease of CD4+ and CD8+ T-cells have been observed in severe cases. These are only a few examples of the COVID-19 biomarkers that have been found. There are many others types such as B-cell depletion, coagulation, and metabolism biomarkers.
Figure 2: Clinical Interventions with higher degrees of predictability
With precision medicine and the use of biomarkers, pharmaceuticals, vaccines and other clinical interventions can be developed rapidly with a higher degree of predictability. As different strains of SARS-CoV-2 inevitably appear and spread, it is vital that precision medicine is implemented in developing treatments.
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