medwireNews: People with cancer who have received COVID-19 vaccination are significantly less likely to experience persistent symptoms after recovery than unvaccinated individuals, irrespective of viral strain, suggest OnCovid data.
The researchers explain that the registry collates information on patients with a laboratory-confirmed diagnosis of SARS-CoV-2 infection and a history of solid or hematologic malignancy (either active or in remission), with the current analysis focusing on the 1909 individuals who were diagnosed between February 2020 and June 2022 and underwent at least one post-COVID-19 clinical assessment.
In all, 16.6% of patients reported at least one COVID-19 sequela at the first assessment, with the most common being respiratory sequelae and prolonged fatigue, in 9.0% and 7.0%, respectively.
When assessed by time periods, the prevalence of COVID-19 sequelae was highest, at 19.1%, in the prevaccination phase, between February 27 and November 30, 2020 (n=1000). This was comparable to the 16.8% rate observed during the alpha–delta phase (December 1, 2020–December 14, 2021; n=653), but it was significantly higher than the 6.2% rate in the omicron phase (December 15, 2021–January 31, 2022; n=256).
After excluding participants with unknown vaccination status, the prevalence of sequelae did not differ significantly among unvaccinated individuals diagnosed during the alpha–delta and omicron phases compared with the prevaccination phase, at 18.3% and 9.4% versus 19.1%, respectively.
And the investigators found that COVID-19 sequelae occurred in a significantly lower proportion of patients who had received two doses (n=183) or a booster dose (n=136) of a COVID-19 vaccine than unvaccinated or partially vaccinated patients (n=1489), at 9.8% and 7.4% versus 18.5%, respectively.
This was also the case specifically for respiratory sequelae, which occurred in 6.0% of individuals who received two doses, 4.4% of those who received a booster, and 9.9% of those who were unvaccinated or partially vaccinated, and prolonged fatigue, with corresponding rates of 5.4%, 2.2%, and 7.7%.
By contrast, there was no significant difference in the prevalence of weight loss, neurologic sequelae, or other sequelae by vaccination status, report Alessio Cortellini, from Imperial College London in the UK, and colleagues in The Lancet Oncology.
They also present the findings of an inverse probability of treatment weighting-fitted logistic regression analysis, which showed that vaccinated patients had a significantly lower risk for overall COVID-19 sequelae, at an odds ratio (OR) of 0.41, as well as for respiratory sequelae and fatigue, with respective ORs of 0.52 and 0.49.
The analysis also demonstrated a significant reduction in the risk for overall COVID-19 sequelae among individuals who received two vaccine doses versus unvaccinated participants (OR=0.41), and although there was a numerical reduction in the risk for those who received a booster, this did not reach statistical significance (nonsignificant OR=0.47).
“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.
They add that the results further highlight “the importance of universal vaccination in reducing long-term consequences from COVID-19, maintaining optimal delivery of systemic therapy, and preserving optimal oncological care throughout the evolving phases of the pandemic.”
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Lancet Oncol 2023; doi:10.1016/S1470-2045(23)00056-6