Morphology vs Efficacy: An Analysis into the Effects of Pathogen Morphology on Vaccine Efficacy

Abstract

Although pathogens have been on Earth for millions of years, vaccines have only been used for the last 150. Through rigorous testing and trials, we have been able to manufacture safe and effective vaccines for some of the most infectious diseases existing in the world today. However, not all vaccines work perfect and, in an effort to uncover why, I analyze the effects of various pathogen morphological characteristics on vaccine efficacy and duration of immunity. In order to assess these effects, I compiled data on 25 different infectious diseases from the CDC’s book, “Epidemiology and Prevention of Vaccine-Preventable Diseases”. Once I obtained the efficacy data, I converted it into a probit. By graphing many of the characteristics against vaccine efficacy (as a probit) and immunity, I was able to visualize the relationships between the two. Using the RStudio program, I ran and plotted various linear regressions as a way to aid in the visualization process. The results of the analysis provided better understanding for a few things. First, there is a negative relationship between pathogen surface area and vaccine efficacy. Separating the pathogen data into sphere and rod-shaped pathogens resulted in the same relationship being observed for sphere-shaped but not rod-shaped pathogens. Second, after a certain threshold, surface area appeared to have the same negative effect on duration of immunity. Thirdly, genome size had no effect on vaccine efficacy. As a way to explain these relationships, I theorize that they are the result of larger protein count/size, limited antibody production rate, antibiotic diffusion through a bacteria cell, quick reproduction time and/or genetic mutation. Obviously, further testing will be needed to evaluate the validity of these theories, and if I am lucky, I will be the one to carry that out.