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1.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21258351

RESUMEN

As SARS-CoV-2 variants continue to emerge globally, a major challenge for COVID-19 vaccination is the generation of a durable antibody response with cross-neutralizing activity against both current and newly emerging viral variants. Cross-neutralizing activity against major variants of concern (B.1.1.7, P.1 and B.1.351) has been observed following vaccination, albeit at a reduced potency, but whether vaccines based on the Spike glycoprotein of these viral variants will produce a superior cross-neutralizing antibody response has not been fully investigated. Here, we used sera from individuals infected in wave 1 in the UK to study the long-term cross-neutralization up to 10 months post onset of symptoms (POS), as well as sera from individuals infected with the B.1.1.7 variant to compare cross-neutralizing activity profiles. We show that neutralizing antibodies with cross-neutralizing activity can be detected from wave 1 up to 10 months POS. Although neutralization of B.1.1.7 and B.1.351 is lower, the difference in neutralization potency decreases at later timepoints suggesting continued antibody maturation and improved tolerance to Spike mutations. Interestingly, we found that B.1.1.7 infection also generates a cross-neutralizing antibody response, which, although still less potent against B.1.351, can neutralize parental wave 1 virus to a similar degree as B.1.1.7. These findings have implications for the optimization of vaccines that protect against newly emerging viral variants.

2.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21253131

RESUMEN

BackgroundThe 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. MethodsThis study presents data on the safety and immune efficacy of the BNT162b2 (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 BNT162b2 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) (B.1.1.7). We also collected safety data for the BNT162b2 vaccine up to 5 weeks following first dose. FindingsThe 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. ConclusionsDelayed 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. RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSSome cancer patients have been shown to exhibit sustained immune dysregulation, inefficient seroconversion and prolonged viral shedding as a consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Consequently, their exclusion and, in particular, the exclusion of patients receiving systemic anti-cancer therapies, from the registry trials of the 5 approved COVID-19 vaccines raises questions about the efficacy and safety of SARS-CoV-2 vaccination in this patient population. In addition, whilst the change in the UKs dosing interval to 12-weeks aimed to maximise population coverage, it is unclear whether this strategy is appropriate for cancer patients and those on systemic anti-cancer therapies. Added value of this studyWe report that the RNA-based SARS-CoV-2 BNT162b2 vaccine administered in cancer patients was well tolerated, and we provide first insights into both antibody and T cell responses to the vaccine in an immunocompromised patient population. Implications of all the available evidenceIn cancer patients, one dose of 30ug of BNT162b2 yields poor vaccine efficacy, as measured by seroconversion rates, viral neutralisation capacity and T cell responses, at 3- and 5-weeks following the first inoculum. Patients with solid cancers exhibited a significantly greater response following a booster at 21-days. These data support prioritisation of cancer patients for an early (21-day) second dose of the BNT162b2 vaccine. Given the globally poor responses to vaccination in patients with haematological cancers, post-vaccination serological testing, creation of herd immunity around these patients using a strategy of ring vaccination, and careful follow-up should be prioritised.

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