8th January 2025 – (Toronto) A 19-year-old woman from Canada encountered an unexpected and dramatic side effect after receiving the COVID-19 vaccine—her breast size quadrupled within months. Researchers from the University of Toronto reported that the woman experienced rapid breast growth beginning just a week after her first dose of the Pfizer vaccine in September 2022.
The woman was diagnosed with gigantomastia, a rare condition that leads to excessive and rapid breast growth. The exact causes of gigantomastia, also known as breast hypertrophy, remain largely unknown. Following her first vaccination, she began to feel tingling sensations in her breasts, and these symptoms intensified after her second dose.
Over the next six months, her breast size surged from a B cup to a triple G cup. According to researchers, such cases are exceedingly rare, with fewer than 20 similar instances documented worldwide. Further studies are needed to explore potential triggers and understand the connection between gigantomastia and external factors.
After ruling out other possible causes, the woman underwent breast reduction surgery approximately 11 months after her initial vaccination. By that time, her breast growth had stabilised for over five months. The successful surgery removed a total of 3.57 kilograms (7.85 pounds) of tissue, reducing her size from a triple G to a double D cup. Five months post-surgery, doctors reported no recurrence of growth, although the woman is considering further procedures to achieve her original breast size.
During the pandemic, numerous women reported experiencing breast enlargement after receiving the Pfizer vaccine, a phenomenon that has been informally referred to as the “Pfizer Boob Job.” Many women mistook swollen lymph nodes, a common vaccine side effect, for signs of cancer and sought mammograms.
Experts have emphasised that adverse reactions to COVID-19 vaccines are exceedingly rare and that the benefits of vaccination outweigh potential complications. Serious side effects occur in about one in 200,000 individuals, according to official data from the United States.
