medwireNews: 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.
“Although the correlation between antibody levels after vaccination and clinical protection is yet to be proven, the accumulating evidence supports antibody response as a potential correlate of disease protection,” they write in a research letter to JAMA Oncology.
“Long-term cellular memory could call into question the need for a third BNT162b2 booster dose.”
The study included 95 patients with solid tumors – most commonly gastrointestinal (26%), lung (25%), and breast (18%) cancer – and 66 cancer-free individuals who received two doses of the Pfizer–BioNTech vaccine at an Israeli cancer center.
At a median of 123–124 days after receipt of the second dose, 87% of the cancer patients were seropositive for anti-spike (S) immunoglobulin (Ig)G antibodies, as were 100% of the controls, but the median antibody titer was significantly lower among people with cancer than controls, at 417 versus 1220 AU/mL.
Salomon Stemmer (Beilinson Hospital, Petah Tikva) and colleagues highlight, however, that the median anti-S IgG titers declined over time in both groups.
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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