Adverse drug reactions to the three doses of the SARS-COV-2 mRNA-1273 vaccine in a cohort of cancer patients of a tertiary hospital

Introduction: SARS-CoV-2 vaccines efficacy and safety have been tested in
phase 3 studies in which cancer patients were not included or
underrepresented. Information is scarce regarding safety in this
population.  Methods: The objective of this study is to evaluate
the safety profile of the mRNA-1273 vaccine across cancer 
patients and its relationship to patients’ demographics. This cross
sectional study included patients 18-years or older with solid
malignancies receiving active treatment in our hospital who had received
the three dose schedule of the mRNA9 1273 vaccine and whose side effects
after each dose were recorded. Patient electronic medical records were
reviewed retrospectively to collect tha available information in 2021.
Patients with documented previous infection by SARS-Cov-2 were excluded
from the study. Results: 93 patients met inclusion criteria. Local adverse
drug reactions (ADRs) were reported more frequently after the first and
second dose than after the third (41.9%, 43% and 31.1% of the patients
respectively), while systemic ADRs were reported less frequently after the
first and second dose than after the third (16.1%, 34.4% and 52.6% of the
patients respectively). We found  a statistically significant
association between sex and systemic ADRs after the third dose. 
Cochran-Armitage test showed a statistically significant linear trend, p =
0.012, with higher ECOG score associated with a lower proportion of
patients suffering from systemic side effects. A logistic regression
showed that females had 5.79 times higher odds to exhibit systemic ADRs
after the third dose (p=0.01)  compared to males. Increasing age
was associated with a decreased likelihood of exhibiting ADRs (p=0.016).
Conclusion: mRNA-1273 vaccine shows a tolerable safety profile. The
likelihood of ADRs appears to be associated with gender and age. Its
association with ECOG scores is less evident. Further studies are needed
to elucidate this data in cancer patients.