SOGC Statement on the COVID-19 vaccines and rare adverse outcomes of thrombosis associated with low platelets
On behalf of the Infectious Diseases Committee of the SOGC
Date: April 20, 2021
Many healthcare jurisdictions
in Canada are facing a third wave of COVID-19 pandemic activity, with some
centres rapidly exceeding peak daily case counts, hospital and ICU admissions
compared to previous waves of the virus.1, 2 The current Canadian epidemiological trends are,
at least in part, driven by low rates of vaccine coverage and circulation of
new variants of concern (VOC) of COVID-19 that have been demonstrated to be
more transmissible and severe compared to the wild-type virus which
predominated previously.3, 4
Pregnancy is a known risk
factor for COVID-associated morbidity with data clearly and consistently
illustrating that pregnant individuals are at increased risk for
hospitalization, ICU admission, mechanical ventilation and death compared to
non-pregnant individuals. As a result of these factors, many Canadian centres
are facing increased numbers of pregnant individuals infected with COVID-19
being admitted to the hospital and ICU.5 For many pregnant individuals in Canada, the
risk of being unvaccinated and susceptible to COVID-19 is substantial.
SOGC supports the use of all
available COVID-19 vaccines approved in Canada in any trimester of pregnancy
and during breastfeeding in accordance with regional eligibility
The four COVID-19 vaccines
approved for use in Canada have been demonstrated to be safe and highly
effective for preventing serious disease from COVID-19.6, 7 Passive surveillance has been ongoing on a
global scale and has not detected adverse pregnancy outcomes related to any
COVID-19 vaccinations and emerging evidence shows passive antibody transfer to
infants. Given that pregnancy is a demonstrable risk factor for severe COVID-19
disease, and that emerging reports from major Canadian centres have identified an increased burden of disease affecting pregnant
individuals, the SOGC recommends that all pregnant people
should be eligible to receive
a COVID-19 vaccine.
While international reports
have emerged documenting extremely rare events of arterial and venous
thrombosis associated with low platelets following the adenovirus vector
COVID-19 vaccines (AstraZeneca, COVISHIELD, Janssen COVID-19 vaccines), these events
occur in as few as 1 in every 125,000 to 1 in 1 million people.8, 9, 10, 11 Most
cases have occurred in women <55
years of age, however, this may reflect a workforce gender bias due to the decision to prioritize front-line health
care workers, most of whom identify as female. There is no known association between this
syndrome and pregnancy and no physiologic basis to increase this risk in
Rare adverse outcomes
observed following vaccination with viral vector COVID-19 vaccines should be
discussed in context of the disease they are designed to prevent. Specifically,
approximately 1 in 10 pregnant individuals will require hospital admission and
1 in 100 pregnant individuals will require intensive care following infection
with COVID-19. For some individuals with additional risk factors such as
advanced maternal age, obesity and pre-existing medical conditions, the risk of
morbidity will be substantially higher. Preventing COVID-19 disease among
pregnant individuals must be considered a priority and vaccination is a central
tool to protect individuals from severe COVID-19 infection.
1. Public Health Ontario. Ontario
covid-19 data tool. Available at https://www.publichealthontario.ca/en/data-and-analysis/infectious-disease/covid-19-data-surveillance/covid-19-data-tool?tab=summary.
of Canada. Coronavirus disease (covid-19): Outbreak update. 2020. Available at https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection.html.
NG, Jarvis CI, van Zandvoort K, et al. Increased mortality in community-tested
cases of sars-cov-2 lineage b.1.1.7. Nature. 2021. Available at https://doi.org/10.1038/s41586-021-03426-1.
NL, Gangavarapu K, Zeller M, et al. Emergence and rapid transmission of
sars-cov-2 b.1.1.7 in the united states. Cell. 2021. Available at https://www.sciencedirect.com/science/article/pii/S0092867421003834.
statement regarding pregnant woman with covid-19 in icus in ontario. 2021.
Available at https://sogc.org/common/Uploaded%20files/Latest%20News/EN_Statement-COVID-19_PregnantWomen.pdf.
Advisory Committee on Immunization. Recommendations on the use of covid-19
vaccines. 2021. Available at https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/recommendations-use-covid-19-vaccines.html.
of Canada. Vaccines for covid-19. Available at https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19/vaccines.html.
vaccine astrazeneca: Benefits still outweigh the risks despite possible link to
rare blood clots with low blood platelets. European Medicines Agency. 2021.
Available at https://www.ema.europa.eu/en/news/covid-19-vaccine-astrazeneca-benefits-still-outweigh-risks-despite-possible-link-rare-blood-clots.
vaccine astrazeneca – safety assessment result: The vaccine is safe and
effective in the fight against covid-19. Paul-Ehrlich-Institut. 2021. Available
10. Naci rapid response: Recommended use of astrazeneca
covid-19 vaccine in younger adults. Health Canada. 2021. Available at https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/rapid-response-recommended-use-astrazeneca-covid-19-vaccine-younger-adults.html.
11. Centers for Disease Control and Prevention. Recommendation
to pause use of johnson & johnson’s janssen covid-19 vaccine. Available at https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/JJUpdate.html.
Read the statement HERE