Assessing Immunogenicity of Covid-19 Vaccines in Survivors of Hematological and Solid Cancers
New vaccines developed against SARS-CoV-2 are being distributed to provide individual protection and eventually, herd immunity. As many cancer survivors have weakened immune systems due to their cancer and their treatments, it is not known how effective these vaccines will be in cancer survivors and whether dosing regimens approved for the general population will be appropriate. To address these issues, we propose to enroll a total of ~1000 survivors of either blood or solid cancers into a study of Covid-19 vaccine immunogenicity. Participants will be categorized as to their types of cancer, types of treatment and extent of immune reconstitution. Blood samples will be collected prior to the first vaccine dose, between the first and second dose at a time dependent upon the dosing regimen prescribed or 30 days after the first dose if a single dose regimen is prescribed. Antibody levels before, between and after immunizations will be measured against SARS-CoV-2 spike protein and SARSCoV-2 spike protein receptor binding domain (RBD) by ELISA. Surrogate ELISA SARS-CoV2 neutralization assays and pseudovirus neutralization assays will be done with samples shown to have anti-SARS-CoV-2 antibodies. Levels of antibodies measured by ELISA and SARS-CoV-2 neutralization titre will be compared between groups of cancer survivors and with an age/sex matched control group of 50 healthy persons. Subsets of cancer survivors with high (n = 50) versus low (n = 50) levels of anti-SARS-CoV-2 antibodies will be tested for T cell reactivity against SARS-CoV-2 by ELISPOT assays with synthetic peptides. Results obtained should provide information on which cancer survivors will benefit from standard vaccination protocols and which will require modified protocols to obtain benefit
