Blood clotting disorders, associated mainly with certain adenovirus-based vaccines
Allergic reactions, including rare cases of anaphylaxis
Temporary changes in menstrual cycles, such as heavier bleeding in some individuals
Short-term increases in blood pressure in a small subset of patients
Health authorities emphasize that these events remain uncommon, and the vast majority of vaccinated individuals do not experience serious complications.
What the Vaccines Do Not Do
Despite online claims and misinformation, there is no credible evidence that COVID-19 vaccines cause cancer or alter human DNA. Regulatory agencies have repeatedly stated that the vaccines’ components do not remain in the body long-term and do not interfere with genetic material.
Pfizer and other manufacturers have acknowledged known risks through updated labeling and transparency reports, as required by law, but these acknowledgments do not imply widespread danger or undisclosed long-term harm.
Ongoing Monitoring and Transparency
Vaccine safety continues to be monitored globally through pharmacovigilance systems. As with any medical product used at scale, rare side effects can emerge over time, which is why continuous review remains essential.
Medical experts broadly agree that, for most people—especially those at risk of severe COVID-19—the benefits of vaccination have outweighed the risks, while recognizing the importance of informed consent and individualized medical decisions.
Conclusion
COVID-19 vaccines were developed quickly, but they were not deployed blindly. Nearly five years of data show that serious adverse effects exist but are rare, while claims of severe long-term damage remain unsupported by scientific evidence. Ongoing research and transparency remain key to maintaining public trust.