Pregnant individuals in Ontario have only been designated a priority population for COVID-19 vaccination since late April 2021. Researchers are now able to provide long-sought insights into vaccine uptake in this population. In a study supported by the VSRG and the CITF, Dr. Deshayne Fell and her team at the Better Outcomes Registry & Network (BORN) in Ontario are evaluating province-wide data on COVID-19 vaccination in pregnant individuals. In their first report, the study team unveiled preliminary findings for the period of December 14, 2020 – when Ontario’s COVID-19 vaccination program started – to May 31, 2021.

The study makes use of BORN Ontario’s Registry, which routinely collects maternal and newborn data from all hospitals and midwifery practice groups in Ontario and is linked with the Ontario Ministry of Health’s COVaxON database, which includes COVID-19 immunization events. The research team will continue to evaluate and regularly report on COVID-19 vaccination in pregnant individuals in Ontario.

Key Points:

  • Approximately 129,027 individuals were pregnant during the period of December 14, 2020 – the start of Ontario’s COVID-19 vaccination program – and May 31, 2021, in Ontario. Of these, 30,892 (23.9%) received at least one dose of a COVID-19 vaccine during their pregnancy.
    • 99.3% of those vaccinated for COVID-19 during their pregnancy received their first COVID-19 vaccine dose; 0.7% received only dose 2 because dose 1 was administered prior to pregnancy.
    • Of the vaccines received during pregnancy, most were administered after April 23, 2021, when pregnant individuals were deemed a priority population in Ontario’s COVID-19 immunization program.
    • On average, pregnant individuals received their first COVID-19 vaccination during pregnancy at 25.5 weeks of gestation.
    • Nearly 85% of vaccinated pregnant individuals were still pregnant as of May 31, 2021, which was the end of the current reporting interval.
  • Estimated COVID-19 vaccination in the pregnant population increased during each month of the reporting period and stood at 38.1% of individuals who were pregnant in the month of May 2021.
  • More than half of pregnant individuals who received a COVID-19 vaccine during pregnancy were aged 30 years old or older.
  • These preliminary results do not suggest any pattern of increased risk for adverse outcomes among vaccinated pregnant individuals; however, future epidemiological studies are required to rigorously assess outcomes once a larger number of births are available.

Link to report on the BORN Ontario website is here.