ABSTRACT
Background: The mortality rate due to COVID-19 in kidney transplant recipients (KTRs) is 16.8 to 32%. Vaccination against COVID-19 is expected to contribute to the prevention of infection, severe disease, and mortality; however, it has been reported that the humoral response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in KTRs is poor. Vaccination strategies against COVID-19 vary from country to country, and in Japan, the third dose is given 6 months after the second dose. Few studies have evaluated long-term humoral responses after the second dose of SARS-CoV-2 mRNA vaccine. In addition, the superiority of BNT162b2 vaccine and mRNA-1,273 vaccine in KTRs regarding humoral response is controversial. Methods: Ninety-four KTRs were administered a second dose of the BNT162b2 or mRNA-1,273 vaccines, and anti-spike (anti-S) and anti-nucleocapsid (anti-N) SARS-CoV-2 antibody levels were measured 5 months (149.2 ± 45.5 days) later. The cutoff value of anti-S antibodies was defined ≥50 AU/ml and 1.4 Index for anti-N antibodies. The primary outcome was the rate of seropositivity, and factors associated with an appropriate humoral response were assessed by univariate and multivariate analysis. Results: Of 94 KTRs, only 45 (47.9%) patients were positive for anti-S antibodies. The median anti-S SARS-CoV-2 IgG antibody titers was 35.3 (Interquartile range 3.8 to 159.7). Anti-N SARS-CoV-2 IgG antibodies in all patients were < 1.4 Index. Response to SARS-CoV-2 mRNA vaccines were 43.2 and 65% for BNT162b2 and mRNA-1,273, respectively (p = 0.152). In comparison with high-dose, low-dose of mycophenolic acid was a robust factor associated with an adequate humoral response. Conclusion: The long-term humoral response after a second dose of SARS-CoV-2 mRNA vaccine in Japanese KTRs was poor. In comparison with high-dose, low-dose mycophenolic acid was related to an appropriate humoral response. Five months is too long to wait for a 3rd dose after 2nd dose of SARS-CoV-2 vaccine in KTRs. In this cohort, there was no statistical difference in humoral response to the BNT162b2 and mRNA-1,273 vaccines. Additional large observational studies and meta-analyses are needed to clarify the factors related to an appropriate humoral immune response to COVID-19 vaccination.
ABSTRACT
We report the case of an 85-year-old woman who was transported to our hospital by ambulance with progressively worsening dyspnea and hypoxia. She had no history of contact with any patient with coronavirus disease 2019 (COVID-19). The peripheral arterial oxygen saturation level on a 10 L/min non-rebreather-type mask was as low as 80%. Chest auscultation revealed coarse crackles. After emergency intubation, it was surmised that the probability of heart failure was low because of the lack of pink, frothy sputum. Bacterial pneumonia was also considered to be unlikely, as the sputum was not purulent. Moreover, laboratory data revealed a normal white blood cell count (6,100/μL) and no elevation of the serum procalcitonin level (0.63 ng/mL), which were also consistent with the condition not likely to be a bacterial infection. Pulmonary thromboembolism was ruled out by the presence of coarse crackles on chest auscultation and normal blood pressure. Thereafter, the possibility of COVID-19 was considered and the patient was immediately isolated. Two days later, the polymerase chain reaction test for COVID-19 returned positive. There was no evidence of transmission of the virus to the healthcare personnel who had treated this patient, including the 6 with medium-risk exposure, during the 3-week period after the exposure. In the COVID-19 pandemic era, rapid differential diagnosis of hypoxia is essential to prevent further transmission of SARS-CoV-2 infection. Our case highlights the importance of the sputum appearance/characteristics and laboratory data for rapidly ruling out diseases other than COVID-19.