During the Covid-19 pandemic, despite several challenges encompassing pathogenesis and several variants, the vaccines have been found effective so far. The development P a g e 10 | 56 process of all the vaccines against COVID-19 up till now by utilizing modern techniques has been reviewed in a recent paper. Moreover, the challenges, clinical trials, and lessons learned from their discovery have also been highlighted in the study . Biological sex, age, composition of microbiome, and geographical location are the host genetic and environmental factors or variables that significantly influence both innate and adaptive immune responses to vaccines. The next-generation vaccines development for SARS-CoV 2 and their efficacy might be impaired if these factors are not taken into consideration. The majority of the studies have focused on adaptive responses, but innate immune response mobilization is also equally crucial for effective cellular as well as humoral immunity. Therefore, a holistic and unbiased approach is needed for identification of environmental factors that contribute to the discovery of the immune responses against the SARS Cov-2 vaccine and also for the optimization of immunogen and also for the development of vector. Moreover, defining the innate immunological mechanisms that underlie the development of long-lived plasma cells and T-cells might lead to the development of a universal Coronavirus vaccine which is a key focus nowadays .