Response to Sriwijitalai and Wiwanitkit re: “The Association of Programmed Death 1 Gene Polymorphisms of PD1.3 G/A and PD1.5 C/T with Risk of COVID-19 in an Iranian Population: A Case-Control Study”

To the Editor:

COVID-19 is a multifactorial disease, and from the genetic aspect single nucleotide polymorphisms (SNPs) are just one of the risk factors for the disease. In response to the correspondence by Sriwijitalai and Wiwanitkit (2022), our study concluded that PD1.5 SNP might increase the risk of COVID-19 in Iranian ethnicity. Definitely different factors may influence the susceptibility to COVID-19. However, regarding vaccination and circulating variants, it is important to note that none of our patients received COVID-19 vaccines before or during the study. Given the nonrobust genomic data surveillance in Iran, it is difficult to trace the dynamics of SARS-CoV-2 variants and be proactive with their related preventive measures (Rayati Damavandi et al, 2022).

In conclusion, despite limitations in our study, we tried our best to present clear outcomes that future researchers could benefit from and shed light on further COVID-19 risk factors.