Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 2 de 2
Add filters

Document Type
Year range
Journal of the American Society of Nephrology ; 32:96, 2021.
Article in English | EMBASE | ID: covidwho-1489631


Background: Patients under hemodialysis are at higher risk of developing severe complications upon SARS-CoV-2 infection and were prioritized in the Portuguese vaccination campaign. Methods: We performed a longitudinal analysis of antibody responses upon vaccination with BNT162b2 mRNA (Pfizer/BioNTech, Comirnaty) in a cohort of 156 hemodialyzed patients. Direct ELISA was used to quantify IgG, IgM and IgA anti-fulllength Spike antibody levels against calibrated sera from naturally infected patients at three points: day of the first vaccine dose (t0);3 weeks later (day of the second dose, t1), and 3 weeks after the second inoculation (t2) for 143/156 patients. Anti-n was also measured in t0 and patients anti-n positive were excluded. Results: We observed that 90.9% of the patients developed anti-spike IgG antibodies after the second vaccine dose (t2). Seroconversion was remarkably low at t1 after the first vaccine dose with only 29.4% of patients developing anti-spike IgG antibodies. In addition to positivity, the second vaccine dose markedly increased IgG antibody levels. IgA levels were also higher at t2 with 83.9% of the patients achieving positivity while IgM positivity only reached 29.4%. Age showed a significant negative effect on the humoral response at t2 for anti-Spike IgG and for IgM, particularly over 60 years. Further analysis revealed that nine patients under immunosuppression therapies showed significantly lower humoral response along the vaccine schedule (p=0.005 at t1;p=0.008 at t2). Interestingly, the inability to develop anti-HBs antibodies upon hepatitis B vaccination frequently found in hemodialyzed patients was not correlated with lack of responsiveness to SARS-CoV-2 vaccination. Conclusions: The large majority hemodialyzed patients showed a significant humoral response to BNT162b2 mRNA vaccination, but a sizable proportion of patients showed low antibody levels when compared to responses in the general population (medRxiv 2021.03.19.21253680).

Annals of Oncology ; 32:S1147, 2021.
Article in English | EMBASE | ID: covidwho-1432892


Background: Cancer patients (pts) have higher risk of severe COVID-19 infection. However, observations are based on non-comparative retrospective studies. Evidence regarding vaccination in cancer pts is limited, but there is enough evidence to support COVID-19 vaccination, even under active treatment. Data on humoral and cellular immune response to antiviral vaccination in cancer pts are scarce. In pts receiving immunosuppressive therapies (IST) like chemotherapy and targeted therapies, seroconversion/protection rates are expected to be lower than general population, but not in pts receiving immune checkpoint inhibitors (ICI). Serum antibodies against an infectious agent may be an immunity indicator. Methods: Prospective observational longitudinal study with the intent of evaluating the humoral response of cancer pts to COVID-19 vaccination. The study includes pts diagnosed in any stage, without or under active treatment, or survivors followed in Hospital Prof. Dr. Fernando Fonseca, in partnership with Instituto Gulbenkian de Ciência. Pts are divided into 4 arms, independently of the vaccine: A – IST;B – ICI;C –Hormone therapy (HT);D – Cancer survivors. Recruitment started in March 2021, expecting at least 50 pts per arm. IgG, IgA and IgM anti-SARS-CoV-2 antibodies ELISA determination in 9 timepoints: before 1st dose and at the 3rd, 6th, 12th, 15th, 24th, 36th, 48th and 60th weeks post 1st dose. Side effects’ questionnaire will be implemented after 1st and 2nd doses. Results: Recruitment is ongoing and a total of 202 pts were enrolled, of which 178 pts have 3-weeks post 1st dose evaluated: 101 in arm A: 11 in B: 31 in C;and 35 in D.The mean age is 61.6 years, with 53.4% females. Regarding vaccines, 55 pts were submitted to ChAdOx1-S/nCoC-19, 5 to Ad26.COV2.S, 89 to BNT162b2 and 12 to mRNA-1273 vaccines. At 3 weeks, 33/97 pts (34%) in arm A, 2/11 pts (18%) in B, 14/28 pts (50%) in C and 15/35 pts (43%) in D already generated anti-spike IgG. Most common side effects were local inflammatory reaction (47%), generalized muscle pain (17%), fatigue (11%), and chills (10%). Conclusions: Efficacy and safety profiles of vaccines against COVID-19 infection in cancer pts is still unknown.This study hopes to assess differences in immunization between pts’ treatment profiles and duration profiles and safety profiles. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.