Dear Editor, we would like to share ideas on the publication “Reactogenicity Study of mRNA Vaccines Against COVID-19¹.” Inglés Torruella et al. compare the reactogenicity of two types of mRNA vaccines against COVID-19, Commirnaty® (Pfizer) and Spikevax® (Moderna), in a healthcare population¹. According to Inglés Torruella et al., the greater reactogenicity and its consequences for the first and second doses of the Spikevax® vaccine compared to Comirnaty®, and for the second dose compared to the first dose of both vaccines, provides useful knowledge for planning COVID-19 vaccination campaigns in healthcare settings¹.

A variety of factors need to be looked at in order to fully understand the results. It is impossible to draw a relationship between asymptomatic COVID-19 and the lack of symptoms without the required laboratory investigations. Without extensive laboratory testing, asymptomatic COVID-19 and the lack of clinical symptoms could be incorrectly diagnosed. A silent COVID-19 must be ruled out if neither the most recent clinical signals nor the most recent clinical markers are present². Additionally, genetic variations appear to affect how certain individuals' immune systems react to COVID-19³. Before the findings can be verified, more clinical study will be needed.