 This study examined the effectiveness of three different types of COVID-19 vaccinations over a six-month period. It found that the AD26.cov2.s vaccine had the highest levels of neutralizing antibodies at six months, while the BNT-162B2 and mRNA-1273 vaccines had lower levels of neutralizing antibodies. Additionally, certain demographics such as age, gender, weight, and smoking status were found to affect the level of neutralizing antibodies produced by each vaccine. This article was authored by Eric A. Prather, Ethan G. Dutcher, James Robinson, and others.