Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2022

Immune response to COVID-19 vaccination in adults and children with cancer: results from the prospective SerOzNET study. (#102)

Amy Body 1 2 , Elizabeth Ahern 1 2 , Hesham Abdulla 1 , Luxi Lal 1 , Stuart Turville 3 , Zin Naing 4 , Stephen Opat 5 , Michael Leahy 6 , Nada Hamad 7 , Katie Lineburg 8 , Corey Smith 8 , Robert McCuaig 8 , Sudha Rao 8 , Raina McIntyre 3 , Noemi Fuentes-Bolanos 9 , Bhavna Padhye 10 , Lucy Busija 2 , Peter Downie 11 , Vivienne Milch 12 , Eva Segelov 1 2
  1. Medical Oncology, Monash Health, Clayton, VIC, Australia
  2. Monash University, Clayton, VIC, Australia
  3. The Kirby Institute, University of New South Wales, Sydney, NSW, Australia
  4. NSW Health Pathology, Sydney, NSW, Australia
  5. Haematology, Monash Health, Clayton, VIC, Australia
  6. Haematology, Royal Perth Hospital, Perth, WA, Australia
  7. Haematology, St Vincent's Hospital, Sydney, NSW, Australia
  8. QIMR Berghofer, Brisbane, QLD, Australia
  9. Oncology, Sydney Children's Hospital, Sydney, NSW, Australia
  10. Paediatric Oncology, Westmead Hospital, Sydney, NSW, Australia
  11. Paediatric Oncology, Monash Health, Clayton, VIC, Australia
  12. Cancer Australia, Sydney, NSW, Australia

Background:

Adults and children with cancer are susceptible to severe SARS-CoV-2 disease. Vaccination is protective; data beyond initial response and regarding effect of booster doses are lacking in cancer patients.

Methods:

The SerOzNET study assesses SARS-CoV-2 vaccine response in haematological and solid cancer patients aged 5 and older. Patients are recruited pre dose 1 and receive standard BNT162b2 (Pfizer) or ChadOx1-S (AstraZeneca) vaccine. Blood is taken at baseline and after each dose. Neutralising antibody (NAb) titre, absolute antibody titre (Abbott), T cell response (IFN-γ) and epigenetics are analysed. Clinical data are collected. Patients are followed for up to 3 months beyond dose 5.

Results:

105 children (64% haem, 36% solid cancers) and 399 adults (35% haem, 65% solid cancers) were enrolled.

In adults, NAb response rate increased after dose 3 (Post 2: 40% haem, 87% solid; Post 3: 70% haem, 97% solid). Post dose 2, predictors of non-response were ChadOx1-S vaccine (OR 3 p=0.02), haem cancer (OR 14 p<0.001), ECOG ≥1 (OR 2.6 p=0.01) and steroids (OR 5 p=0.01). Post dose 3, only haem cancer predicted non-response (OR 16). IFN-γ response is available for a subset, detectable in 41/90 (46%) post-dose 1, 78/96 (81%) post-dose 2 and 35/42 (83%) post-dose 3; without significant difference between haem and solid cancer.

In children, NAb response post dose 2 is available for 50 patients. Response rate between haem (19/31, 61%) and solid patients (13/19, 68%) was similar. IFN-γ response post dose 2 was also similar: (14/22, 63%) vs solid patients (12/14, 85%) (p=0.25). Analysis is ongoing.

Conclusions:

Response to 2 doses of SARS-CoV-2 vaccine is suboptimal in patients with cancer. The third priming dose is integral, with significantly higher response rates observed. 36% of children did not develop neutralising antibodies post dose 2; subsequent doses are likely to be important for young patients.