They therefore investigated the clinical efficacy of the vaccines in a cohort of 1503 patients who received one or two doses of a COVID-19 vaccine between January 4 and April 6, 2021, at their institution.

“Although we cannot mechanistically prove the protective role of SARS-CoV-2 vaccines against COVID-19 sequelae, the underlying causative link is biologically plausible and represents a potentially practice-informing finding despite possible sources of heterogeneity, including selection and ascertainment bias,” write Cortellini et al.

A Canadian population-based study has confirmed that people with cancer have an increased risk of breakthrough COVID-19 infection after vaccination, while UK research points to the feasibility of SARS-CoV-2 antibody testing to identify those with the lowest level of vaccine-derived protection.

The study included data from 39 phase 2 or 3 randomized controlled trials (RCTs) comparing ICI use (anti-PD-1/PD-L1 and/or anti-CTLA-4 therapy) with non-ICI drugs (chemotherapy, targeted therapy, vaccines, or combination therapies) and placebo in 23,705 patients (68.0% men, 33.1% White) with various cancers.

Research from three countries adds support for the use of a booster dose of vaccines against SARS-CoV-2 in people with cancer, especially those undergoing active anticancer treatment.

People with cancer remain susceptible to severe outcomes after developing breakthrough SARS-CoV-2 infection despite being fully vaccinated, research suggests.

“Whether such responses can be boosted by COVID-19 vaccines remains under investigation in the vaccine cohort of our study, which includes the currently predominant Delta VOC.”

People with cancer could benefit from a booster dose of the Pfizer–BioNTech SARS-CoV-2 vaccine, suggest data from Israel.

A prospective cohort study suggests that patients with cancer on active treatment have a higher risk for poor seroconversion after two doses of the Pfizer–BioNTech COVID-19 vaccine than those undergoing active surveillance.

And they conclude: “Although further studies are needed to determine if these data are also applicable to the other COVID-19 vaccines, our findings might provide some reassurance for their use in patients being treated with immune checkpoint inhibitors.” medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group 8 April 2021: The coronavirus pandemic is affecting all healthcare professionals across the globe.

A small phase 1 trial suggests that a third booster dose of the Pfizer–BioNTech vaccine in patients receiving anticancer therapy could improve their immunologic response to SARS-CoV-2.

Speaking at the ESMO Congress 2021, Sjoukje Oosting (University Medical Center Groningen, the Netherlands) explained that the VOICE investigators examined the efficacy of SARS-CoV-2 vaccines in people receiving anticancer treatment as “chemotherapy and immunotherapy may impact the ability to mount an effective immune response to vaccination and could increase the risk of adverse events.”

The study, by Mizuki Nishino and colleagues from the Brigham and Women’s Hospital and Dana-Farber Cancer Institute in Boston, Massachusetts, USA, included 232 individuals who received two doses of mRNA-based COVID-19 vaccines between December 2020 and April 2021.

Noting that mRNA vaccines “have already been explored in cancer,” Liu believes the vaccine-associated risks for these patients are low.

They explain in a comment published in The Lancet Oncology that “[b]ecause radiotherapy might affect the immune system by both suppressing and enhancing the immune response, the safety of the COVID-19 vaccines might be different in this specific setting.”

Multiple vaccines have been approved by regulatory agencies around the world.

The seropositivity rate in response to the Pfizer–BioNTech (BNT162b2) vaccine against SARS-CoV-2 remains high around 4 months after the second dose in cancer patients undergoing active therapy, report Israeli researchers.

Women with cancer appear to be more reticent about receiving COVID-19 vaccination than men, indicates a single-center study.

A single-center study of women undergoing breast imaging after COVID-19 vaccination has revealed a higher than usual rate of axillary adenopathy.

All patients with no history of COVID-19 received two vaccines doses.