Interim results of the safety and immune-efficacy of 1 versus 2 doses of COVID-19 vaccine BNT162b2 for cancer patients in the context of the UK vaccine priority guidelines

Abstract

Background: The efficacy and safety profile of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been definitively established in immunocompromised patient populations. Patients with a known cancer diagnosis were hitherto excluded from trials of the vaccines currently in clinical use. Methods: This study presents data on the safety and immune efficacy of the BNT162b.2 (Pfizer-BioNTech) vaccine in 54 healthy controls and 151 mostly elderly patients with solid and haematological malignancies, respectively, and compares results for patients who were boosted with BNT162b.2 at 3 weeks versus those who were not. Immune efficacy was measured as antibody seroconversion, T cell responses, and neutralisation of SARS-CoV-2 Wuhan strain and of a variant of concern (VOC) (B1.1.7). We also collected safety data for the BNT162b2 vaccine up to 5 weeks following first dose. Findings: The vaccine was largely well tolerated. However, in contrast to its very high performance in healthy controls (>90% efficacious), immune efficacy of a single inoculum in solid cancer patients was strikingly low (below 40%) and very low in haematological cancer patients (below 15%). Of note, efficacy in solid cancer patients was greatly and rapidly increased by boosting at 21-days (95% within 2 weeks of boost). Too few haematological cancer patients were boosted for clear conclusions to be drawn. Conclusions: Delayed boosting potentially leaves most solid and haematological cancer patients wholly or partially unprotected, with implications for their own health; their environment and the evolution of VOC strains. Prompt boosting of solid cancer patients quickly overcomes the poor efficacy of the primary inoculum in solid cancer patients.

Quantitative SARS-CoV-2 anti-spike responses to Pfizer-BioNTech and Oxford-AstraZeneca vaccines by previous infection status

“…Antibody testing post-vaccination may also play other roles. It may be useful to identify individuals in high risk groups who do not seroconvert 19 , who may remain at higher risk of infection, and may benefit from tailored advice around social contact, and, depending on underlying comorbidity, from further vaccination doses e.g. if immune reconstitution is expected.…”

Correlation Between BNT162b2 mRNA Covid-19 Vaccine-associated Hypermetabolic Lymphadenopathy and Humoral Immunity in Patients With Hematologic Malignancy

“…Polack et al investigated the safety and e cacy of the BNT162b2 mRNA Covid-19 vaccine in healthy adults or those with chronic stable medical conditions, excluding patients treated with immunosuppressive therapies or diagnosed with immunocompromising conditions [1]. It was later observed that in immunocompromised patients, the elicited immune response to mRNA Covid-19 vaccine is reduced [2][3]. Boyarsky et al showed the poor humoral response elicited in a study of 346 solid organ transplant recipients [2].…”

“…Boyarsky et al showed the poor humoral response elicited in a study of 346 solid organ transplant recipients [2]. Monin-Aldama et al showed that the post-BNT162b2 immune e cacy was strikingly low in solid cancer patients and even lower in patients with hematologic malignancy [3].…”

“…Data on the immune response elicited by anti-SARS-CoV-2 vaccines is being accumulated in various patient cohorts [1][2][3][4]. Polack et al investigated the safety and e cacy of the BNT162b2 mRNA Covid-19 vaccine in healthy adults or those with chronic stable medical conditions, excluding patients treated with immunosuppressive therapies or diagnosed with immunocompromising conditions [1].…”

Informing COVID-19 vaccination priorities based on the prevalence of risk factors among adults in Canada

“…1, 2021; the CDC began permitting a delay of up to 6 weeks for second doses of mRNA vaccines on Jan. 21, 2021. One caveat to this approach is that data around the durability of first-dose protection are lacking for some subgroups, such as older adults, people who are immunocompromised or patients with cancer, 27 given concerns that prolonged viral replication in immunocompromised hosts may promote the emergence of more SARS-CoV-2 variants. 28 Our analysis not only informs Canadians wondering how many others are in the same risk stratum as they, but also serves to emphasize the importance of continuing to follow public health advice such as universal masking, physical distancing and frequent hand washing as vaccination programs proceed, given that most adults in Canada have at least 1 risk factor for severe COVID-19.…”