The FDA is reportedly considering adding a ‘black box’ warning to COVID-19 vaccines, signaling its most severe caution regarding potential side effects. This development, as suggested by insiders, underscores the agency’s commitment to transparency concerning vaccine safety.

According to sources who spoke to CNN under the condition of anonymity, due to their lack of authorization to discuss the matter publicly, the FDA is in the preliminary stages of implementing this warning. A black box warning is prominently displayed on medication labels to alert healthcare providers and patients about significant risks, such as severe adverse effects or specific usage restrictions.

While the precise details of the warning remain undisclosed, and it’s still uncertain whether it will pertain solely to mRNA COVID-19 vaccines or encompass all types, the initiative reflects the FDA’s cautious approach to public health safety.

Leading the charge in this potential regulatory update is Dr. Vinay Prasad, a hematologist-oncologist who serves as the director for the FDA’s Center for Biologics Evaluation and Research (CBER). This center plays a crucial role in assessing the safety and efficacy of biological products, including vaccines.

One individual said the effort was being led by Dr Vinay Prasad, a hematologist-oncologist and the FDA’s director for the Center for Biologics Evaluation and Research (CBER), the center that evaluates products such as vaccines for their effectiveness and safety.

Dr Prasad raised concerns over Covid vaccines late last month, saying in an email to staff that ‘at least’ 10 children had died after receiving the shots, although he did not reveal further details. The FDA has now launched a thorough investigation into the reports.  

Officials stressed that discussions were still in the early stages and that no changes to the warnings had been finalized.

A spokesman for the Department of Health and Human Services said: ‘Unless the FDA announces it, any claim about what it will do is pure speculation. The FDA takes very seriously any death that is attributed to a regulated medical product.’

Officials are considering placing a black box warning on Covid vaccines, reports suggest (stock image)

There are three Covid vaccines available in the US, the Moderna and Pfizer vaccines, which use mRNA, and the Novavax vaccine, which uses the virus’s spike protein, and none currently carry a black box warning on their label.

In July, the FDA updated the warning label for the Pfizer and Moderna Covid vaccines to warn that the risk of myocarditis and pericarditis, inflammation of the membranes surrounding the heart, was highest among males aged 12 to 24 years.

The agency typically notifies the public that it is looking into a safety question around a drug or vaccine before adding a black box warning to a label. It may also convene an advisory committee, a panel of independent experts, to analyze safety data and advise whether the black box warning is warranted.

The warnings are intended to bring the attention of consumers and physicians to a serious side effect. They may be used if there is evidence of a severe, life-threatening or permanently disabling risk from a medication.

Black box warnings are on the labels for other drugs including opioids, which warn about the risks of abuse, addiction, overdose and death. The smallpox and mpox vaccine, ACAM2000, also has a warning about complications such as heart inflammation and encephalitis.

A former federal health official, who also declined to be named, expressed concern that the new label could lead to distrust in vaccines that have been shown to be safe. 

Rory Nairn (pictured here), a 26-year-old from New Zealand, died from myocarditis 12 days after receiving his first dose of the Pfizer Covid vaccine in 2021

Rhian Griffiths, from the UK, was otherwise fit and healthy when she suffered a cardiac arrest in 2023 at age 32. After her death, she was diagnosed with myocarditis. Her family suggested her ‘unknowingly catching Covid had this effect on her heart

They told CNN: ‘What’s happening now is death by a thousand cuts.

‘What we’re watching is misinformation and lies in aggregate that will discourage the population from vaccination. It will lead us to, ultimately, to having loss of life unnecessarily, and it’s very disturbing.’

The potential decision comes after a Stanford University study published yesterday revealed how Covid mRNA shots can cause myocarditis, an extremely rare complication of the vaccine that causes inflammation of the heart muscle.

The study author, Dr Joseph Wu, a cardiologist at the university, denied that his work showed Covid mRNA vaccines should no longer be offered to young men.

He told Daily Mail: ‘The incidence of myocarditis after mRNA vaccination remains very low, even among young males. Importantly, Covid infection itself poses a substantially higher risk of myocarditis than vaccination.’

He added: ‘Based on current clinical evidence, existing public health recommendations continue to support vaccination, ideally guided by individualized discussions between patients and their healthcare providers.’ 

Data shows about one in 125,000 children and adults under 65 who were vaccinated against the virus between 2023 and 2024 developed the condition within seven days of their inoculation. 

Among men and boys under 25 years old, however, the rate rose to one in 37,000, or 3.4 per 125,000.

Among people who are infected with Covid, a 2023 analysis suggests up to one in 950 suffer from myocarditis, equivalent to one in 950.

A CDC presentation from June also showed that most adolescents and young adults who developed myocarditis after vaccination recovered. The condition is not known to have led to any deaths or heart transplants in the US.

About 270 million people in the US, or 81 percent of the population, have received at least one dose of the mRNA Covid vaccine to date.

The US government says it has received 10,000 claims that someone suffered an injury or death after taking a Covid vaccine.

Shown above is the panel debating the CDC’s vaccine recommendations in Atlanta, Georgia, in September this year

The Commonwealth fund, a foundation supporting better access in the US healthcare system, estimates that the shots saved 3million lives and prevented 18million hospitalizations in the US alone in the first two years of the rollout.

But the vaccines have been subject to increasing scrutiny in the US and other nations after officials continued to recommend them to everyone aged six months and over annually, despite the fact that children and young adults faced a low risk of hospitalization and death from the virus.

Earlier this month Dr Robert Redfield, who headed the CDC during Trump’s first term, said he did not support the continued use of mRNA Covid vaccines.

In September, the CDC’s vaccine panel, the Advisory Committee on Immunization Practices (ACIP), voted to remove the recommendation that everyone aged six months and older should get the Covid vaccine, and instead told Americans to get the vaccine based on ‘individual decision-making’.

Health and Human Services Secretary Robert F Kennedy Junior, who selected the ACIP panel, has previously criticized the Covid vaccine rollout.