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Several pharmaceutical companies, including Pfizer, AstraZeneca, Moderna, and Johnson & Johnson, developed COVID-19 vaccines in record time. While this rapid progress was celebrated, it also sparked questions and concerns about safety and potential side effects.
After millions of doses administered and nearly five years of follow-up, medical specialists have identified some confirmed adverse effects. These include high blood pressure, myocarditis or pericarditis, allergic reactions, and heavy menstrual bleeding.
Despite these findings, there remains debate over whether the vaccines directly cause serious illnesses. Many scientists and healthcare professionals continue to evaluate data, emphasizing that most side effects are rare relative to the number of people vaccinated.
A recent large-scale study aimed to clarify these risks. Conducted by the Global Vaccine Data Network, it analyzed data from over 99 million people across eight countries: Argentina, Australia, Canada, France, Denmark, Finland, New Zealand, and Scotland. Results were published in the journal Vaccine.