Vaccines | Free Full-Text | Anti-SARS-CoV-2 Vaccination and PIMS-TS—Friends or Foe? Case Reports and Literature Review

The link between COVID-19 vaccination and the development of PIMS-TS remains uncertain due to the syndrome’s complex pathogenesis. Some reports suggest a potential association between vaccination and PIMS-TS onset, but deeper analysis often reveals these cases to be coincidental or influenced by pre-existing factors rather than directly caused by the vaccine (Table 8). For example, Jain et al. [22] and Collignon et al. [23] reported cases with a short interval between vaccination and PIMS-TS symptoms, suggesting other factors at play. Similarly, cases reported by Consollini et al. [24], Salzman et al. [25], and DeJong et al. [26] involved prior SARS-CoV-2 exposure, complicating the causal link to vaccination. In another case, Lee et al. described a child who developed PIMS-TS MIS-C after being exposed to COVID-19 despite the vaccination [27]. Santilli et al. reported PIMS-TS in two children with high somatic burdens shortly after COVID-19 vaccination, suggesting a potential link to an inadequate vaccine response [28]. Oudali et al. found 12 PIMS-TS cases among over 8000 patients, with 10 showing cardiac issues akin to post-vaccination myocarditis despite no prior SARS-CoV-2 contact [29]. Yalçinkaya et al. observed PIMS-TS in two individuals 27 days post-Moderna vaccine, with no anti-N antibodies detected [30]. Wangu et al. described a PIMS-TS case 10 weeks after the second vaccine dose, also without prior virus exposure [31]. Yousaf et al.’s analysis of over 21,000 vaccinated children revealed 8 PIMS-TS cases post-Pfizer vaccine with no SARS-CoV-2 contact history and 15 MIS-C cases post-vaccine with prior virus exposure, indicating a median onset of 34–35 days for PIMS-TS symptoms [32]. Varghese reported a potential PIMS-TS case in an 18-year-old 3 weeks after his third Pfizer dose, with no previous infection signs [33]. These cases suggest a possible, albeit rare, association between COVID-19 vaccination and PIMS-TS development, warranting further investigation. In many of the described cases, the presence of antibodies against the N protein of the virus was observed, which indicates previous contact with a person infected with the SARS-CoV-2 virus. In addition, a clinical study of the mRNA vaccine in a group of children 6-11 years of age showed no cases of PIMS-TS after vaccination [9]. Of course, this does not completely exclude the possibility that the vaccine becomes a trigger point in a predisposed person. However, such data argue against the possibility that vaccination by itself, via contact with the vaccine antigen alone, could cause PIMS-TS. In addition, in currently available literature, some cases have described children who have been diagnosed with type I diabetes, sickle cell anemia, or autoimmune diseases that may cause too weak antibody response. On the other hand, some authors managed to list extremely rare cases of developing PIMS-TS in temporal with vaccination and without prior contact with the virus. The course similar to myocarditis described as a complication after this vaccine indicates the need for meticulous and reliable reporting of changes in health status and extreme caution in assessing changes in the health status of children and considering PIMS-TS as a diagnosis despite (or because of) vaccination. In our case, it should be assumed that the boy developed PIMS-TS due to a combination of different factors rather than as a result of vaccination alone.