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COVID-19

COVID-19 Vaccines Offer Limited Protection to Double-Vaccinated Blood Cancer Patients

Strategic Insights

— 2 min read

Blood cancer patients who have been double-vaccinated against COVID-19 are still left vulnerable to the virus, with more than half unable to mount an antibody response to SARS-CoV-2, researchers have found. The study, which was published in a letter to Cancer Cell, examined the immune protection offered by delayed Pfizer vaccine boosts in 159 participants, including 128 cancer patients. While some solid cancer patients showed strong responses to a second vaccine dose, blood cancer patients continued to remain extremely vulnerable, highlighting the importance of continued public health measures to limit SARS-CoV-2 transmission.

Key Takeaways:

  • Over 50% of double-vaccinated blood cancer patients showed little protection against COVID-19, with only 36% achieving antibody and T cell responses.
  • Solid cancer patients, such as those with breast, urological, or skin cancers, showed poor responses to single-dose vaccination, but strong responses to a second dose.
  • Delaying the second vaccine dose in cancer patients did not improve immune response, unlike in healthy controls.
  • Blood cancer patients were still vulnerable to COVID-19 despite being double-vaccinated, with 64% showing no antibody and T cell responses.
  • The study authors urge vulnerable groups to be protected through continued mask-wearing, social distancing, and vaccination of school-age children.
  • The trial was led by a cross-institutional collaboration between King's College London and the Francis Crick Institute, with support from Cancer Research UK.
  • The study highlights the continued need for continued public health measures to limit SARS-CoV-2 transmission, especially in areas with high delta-variant transmission.
  • The lead authors, Dr. Sheeba Irshad and Professor Adrian Hayday, emphasize the importance of masks and other protective measures for blood cancer patients.
  • The study adds to a growing body of evidence confirming the vulnerability of patients with blood cancers during the COVID pandemic despite being vaccinated.

Statistics:

  • 159 participants were assessed in the SOAP-02 trial, including 31 controls, 72 solid cancer patients, and 56 blood cancer patients.
  • 128 cancer patients received the delayed Pfizer vaccine boost, with 64% showing no antibody and T cell responses.
  • 38% of solid cancer patients showed seroconversion rates after single-dose vaccination.
  • 78% of solid cancer patients and 88% of healthy controls achieved antibody and T cell responses.
  • The study highlights the unfavourable situation of blood cancer patients, with only 36% achieving antibody and T cell responses.

Sources:

  • "Delayed Booster Vaccination in COVID-19 Immunized Blood Cancer Patients" (Cancer Cell, 2021)
  • King's College London
  • The Francis Crick Institute
  • Cancer Research UK
  • NewsRx LLC (2021)

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