Dear Editor, we would like to share ideas on the publication “Post-vaccination antibodies against SARS-CoV-2 in a cohort of workers of a general hospital”¹. In the cohort and with fresh SARS-CoV-2 infections, Sabater Vidal et al. noticed a general decrease in IgG-S and IgG-NP antibodies following the second dosage of the Pfizer-BioNTech vaccine ⁽¹. Additionally, Sabater Vidal et al. advocated booster shots, continuing preventative measures, and further research to determine the vaccine's protection threshold¹. We concur that the COVID-19 can boost resistance in research subjects. Recognizing the impact of earlier asymptomatic COVID-19 is crucial, though. Asymptomatic COVID-19 is not unusual, and anyone can have had it in the past². It is important to take into account any potential confounding effects from earlier asymptomatic COVID-19 when interpreting the vaccination's effects.