Immune Response following BNT162b2 mRNA COVID-19 Vaccination in Pediatric Cancer Patients

Area of Science:

• Pediatric Oncology
• Immunology
• Vaccinology

Background:

• COVID-19 vaccination is recommended for pediatric cancer patients.
• Data on the immune response to COVID-19 vaccines in this vulnerable population is limited.

Purpose of the Study:

• To evaluate the antibody and T-cell response to the BNT162b2 mRNA COVID-19 vaccine in children with cancer.
• To assess the impact of treatment timing (chemo/immunotherapy <6 weeks vs. >6 weeks) on vaccine response.
• To determine the efficacy of a 3-dose vaccination series.

Main Methods:

• Assessed antibody response using anti-SARS-CoV-2 spike 1 antibody concentrations (>300 BAU/mL defined as good response).
• Measured T-cell response via spike S1 specific interferon-gamma release (>200 mIU/mL defined as good response).
• Categorized patients based on timing of cancer treatment relative to vaccination.

Main Results:

• A 2-dose series showed lower response rates in patients treated <6 weeks (39.3% antibody, 73.7% T-cell) compared to those treated >6 weeks (94.4% antibody, 100% T-cell).
• A 3rd dose in patients treated <6 weeks increased antibody response to 70% but did not significantly alter T-cell response.
• Patients undergoing active cancer treatment benefited from a 3-dose vaccination schedule.

Conclusions:

• A 3-dose BNT162b2 mRNA vaccination regimen is effective in boosting antibody levels in children with cancer.
• Vaccination timing relative to cancer treatment influences immune response.
• 3-dose vaccination strategies are valuable for immunocompromised pediatric cancer patients.