HERO-Together Boost: A post-Emergency Use Authorization observational cohort study to evaluate the safety of the Pfizer-BioNTech COVID-19 vaccine

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Safety study (incl. comparative)
• Data collection methods:
  Primary data collection

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medicinal product name, other:
  Pfizer-BioNTech COVID-19 vaccine
• Anatomical Therapeutic Chemical (ATC) code:
  (J07BN) Covid-19 vaccines

  Covid-19 vaccines
• Medical condition to be studied:
  COVID-19 immunisation

Population studied

• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Special population of interest:
  Immunocompromised

  Pregnant women
• Estimated number of subjects:
  10000

Study design details

• Study design:
  Prospective, observational, voluntary safety study
• Main study objective:
  To estimate the real-world incidence of safety events of interest among recipients of the Pfizer-BioNTech COVID-19 vaccine following EUA
• Setting:
  The source population will be adults living in the US, whereby after enrollment study participants are followed for up to 18 months. Given the broad source population, the study will apply multiple recruitment strategies to ensure enrollment of a diverse sample to support generalizability of results. The primary study recruitment strategy (pharmacy email invitations) may leverage oversampling of traditionally underrepresented populations to ; ensure adequate representation in the final analytic population.
• Outcomes:
  Incidence of safety events of interest among recipients of the Pfizer-BioNTech COVID-19 vaccine following EUA, Incidence rates of safety events of interest among subcohorts of interest, including individuals who are pregnant, individuals who are immunocompromised, and stratified by age
• Data analysis plan:
  Vaccination and baseline characteristics will be summarized using descriptive statistics, including measures of central tendency and dispersion (means, medians, standard deviations) for continuous variables and percentages for categorical variables. The primary analysis for each objective will be restricted to participants who enrolled within 10 days of vaccination to mitigate the risk of selective enrollment and disproportionate representation of higher risk participants. The number and incidence rate for each safety event of interest will be calculated overall, and within subgroups of interest, including pregnant women, immunocompromised individuals, and within age groups. Rates will also be stratified by other baseline characteristics, such as race/ethnicity, work setting, prior COVID-19, and geographic region, data permitting.
• Summary results:
  The study population was primarily White (82.2%), female (58.7%), not Hispanic or Latino (87.6%) with a mean age of 5 4.3 years ranging from 18 to 88 years and had a low prevalence of comorbidity at Baseline. The incidence proportions of both non-adjudicated (< 1.0%) and confirmed hospitalizations (< 1.0%) due to AESIs was low. Non-hospitalized AESIs were also relatively uncommon, reported by approximately 5.2% of study participants, with non-severe allergic reactions being the most frequent event (1.5% of study participants). All other non-hospitalized AESIs occurred in < 1.0% of participants. Analysis of incidence rates of AESI among subgroups of interest estimate higher rates of confirmed hospitalization among recipients of the Pfizer-BioNTech COVID-19 vaccine who were in the subgroups of immunosuppressed or 70+ years of age, than in strata of immunocompetent or younger ages, respectively.; ; There was poor concordance (kappa=0.26) and a low positive specific agreement (0.33) between claims-based methods and medical record review adjudication for safety event ; confirmation.