medwireNews: French researchers report a low seroconversion rate after one dose of the COVID-19 mRNA vaccine among people with cancer.
“[O]ur findings argue for not extending the 21-day period between the two SARS-CoV-2 vaccine injections in [cancer patients], and for performing serological monitoring to assess antibody response in this particular population,” they write in a letter to the Annals of Oncology.
Among 110 patients with cancer who received one dose of the Pfizer–BioNTech (BNT162b2) vaccine between February 17 and March 18, 2021, at a French hospital, the seroconversion rate against the viral spike (S) protein was 58% at 4 weeks after vaccination.
The rate was 55% among the 95 patients without prior COVID-19 infection, as indicated by the absence of anti-nucleocapsid antibodies, and was 80% among the 15 patients who had had COVID-19.
By contrast, the anti-S seroconversion rate was 100% for the 25 healthcare workers who served as the control population.
Romain Palich (Pitié-Salpêtrière Hospital, Paris) and co-workers highlight that even in cancer patients with seroconversion, median anti-S titers were significantly lower than those observed in controls, at 315 versus 680 UA/mL.
They also identified a significant association between no seroconversion and age over 65 years and receipt of chemotherapy, with odds ratios of 3.58 and 4.34, respectively, after adjusting for confounding factors.
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group
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