A Centers for Disease Control and Prevention (CDC) study of hospitalized veterans showed their antibody response dropped four months after receiving either of the two mRNA COVID-19 vaccines. Published Thursday, the CDC-backed study found that both the Pfizer and Moderna vaccines were effective at preventing hospitalization for veterans four months after they got their second dose, although their COVID-19 antibody levels dropped. Among those who received the Moderna vaccine, scientists recorded “slightly higher” COVID-19 antibody levels than those who received the Pfizer shot. The researchers noted that four months after the Moderna and Pfizer vaccines were administered to the veterans, their effectiveness at preventing hospitalizations was 86 percent and 75 percent, respectively. After their findings, the CDC again recommended that people receive a booster shot months after getting the vaccine. “These findings from a cohort of older, hospitalized veterans with high prevalences of underlying conditions suggest the importance of booster doses to …