Abstract 1602P
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.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.