乌鸦传媒

Cardiovascular events were not more likely for recipients of the Pfizer-BioNTech COVID-19 mRNA bivalent booster compared with the original monovalent booster, according to French researchers.

Their population-based study found no evidence of an increased risk of cardiovascular events at 21 days among the recipients of the bivalent vaccine versus recipients of the monovalent vaccine, including:

• Ischemic stroke: HR 0.86 (95% CI 0.58-1.27)
• Hemorrhagic stroke: HR 0.86 (95% CI 0.46-1.61)
• Myocardial infarction: HR 0.92 (95% CI 0.62-1.36)
• Pulmonary embolism: HR 0.83 (95% CI 0.49-1.40)
• All four events combined: HR 0.87 (95% CI 0.69-1.09)

"Our results provide reassurance regarding the continued use of this bivalent vaccine," wrote Marie-Joelle Jabagi, PharmD, PhD, of the EPI-PHARE Scientific Interest Group in Saint-Denis, France, and colleagues in a correspondence published in the .

The reassuring findings follow a January announcement from the FDA and CDC that the Vaccine Safety Datalink had detected a signal of possible increased risk for ischemic stroke in the 21 days following administration of the Pfizer-BioNTech bivalent booster among recipients ages 65 and older.

However, subsequent analyses of the Vaccine Adverse Event Reporting System, the Centers for Medicare & Medicaid Services database, and a preliminary study of the Veterans Affairs database showed no signal for an increased risk with either Pfizer or Moderna's bivalent vaccines, both of which were first authorized late last summer.

Pfizer-BioNTech's global safety database also found no signal for ischemic stroke with their updated booster, nor have surveillance systems from other countries.

For the current study, Jabagi and colleagues used comprehensive data from the French National Health Data System linked to the national COVID-19 vaccination database. All individuals ages 50 and older who had received a booster dose between Oct. 6 and Nov. 9, 2022 -- a time window which captured the only period in which both vaccines were being given in France -- were included in the study.

Of a total of 470,962 vaccine recipients, 20.6% received the monovalent vaccine and 79.4% received the bivalent vaccine. Mean age was 72.6, 53.8% were women, and 75.6% had received three doses of vaccine prior to the study period. Twenty-seven percent had a previous COVID-19 infection.

Common baseline cardiovascular risk factors included hypertension (55.3%), diabetes (15.9%), and dyslipidemia (34.4%). Cardiovascular diseases included coronary heart disease (9.7%), heart failure (3.0%), valvular heart disease (3.0%), occlusive peripheral arterial disease (2.8%), and heart arrhythmia (11.1%). Monovalent and bivalent groups were well-balanced for these characteristics.

The researchers matched each recipient of the monovalent vaccine with up to five randomly sampled recipients of the bivalent vaccine on the same day. They were followed for 21 days.

Those who received other types of COVID-19 vaccines, such as the Moderna vaccine, and those who were less than 90 days out from their last COVID shot were excluded.

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