Vitamina D e vaccinazione anti-covid-19

Since March 2020, the coronavirus disease 2019 (COVID-19) pandemic cau- sed by the novel coronavirus SARS-CoV-2 (severe acute respiratory syndro- me coronavirus 2) has been posing a serious threat to global public health. Significant efforts have been made by the scientific community to develop different types of vaccines against SARS-CoV-2, such as inactivated whole- virion vaccines, viral vector-based vaccines, mRNA vaccines, DNA vaccines and protein subunit vaccines. To date, nationwide and global vaccination cam- paigns represent critical tools to reach the so-called “herd imunity” aimed at controlling and eventually ending the COVID-19 pandemic. Due to the continuous emergence and spread of novel SARS-CoV-2 viral variants, com- plementary strategies aimed at improving the immunity of the general po- pulation and frail individuals may contribute to increase the effectiveness of COVID-19 vaccines. Therefore, the scientific community is also focused on fac- tors able to determine an effective immune response against the virus after vaccination against COVID-19. Currently, vitamin D deficiency also represents a global pandemic afflicting more than one billion individuals across all age groups. Several observational studies have demonstrated that serum levels of vitamin D are significantly and inversely correlated with the incidence and se- verity of COVID-19. In addition, intervention studies have shown that vitamin D supplementation may have a role in mitigating the clinical progression of COVID-19 in light of the anti-infective, anti-inflammatory and immunomo- dulatory properties exerted by this vitamin. Nevertheless, it remains unclear whether vitamin D supplementation (particularly in subjects with vitamin D deficiency) plays a relevant role in enhancing the effectiveness of different COVID-19 vaccines. Thus, future prospective studies are needed to address this unanswered question. In this Report article, we discuss the relationship between hypovitaminosis D and COVID-19 pathophysiology, as well as the potential mechanisms behind the role of vitamin D as as an immunologic adjuvant for COVID-19 vaccines.

Keywords: COVID-19 vaccines; SARS-CoV-2 vaccines; vitamin D; vaccine adjuvant; immunity.