A prominent committee that advises the US Centers for Disease Control and Prevention (CDC) on vaccine guidelines voted on Friday not to suggest that individuals need a prescription to receive a Covid-19 vaccine. However, the panel did vote to advise that people consult with a healthcare professional before getting the vaccine, emphasizing that coronavirus vaccinations should be a matter of “individual-based decision making.”

The committee’s recommendations followed a lengthy debate filled with intense emotion, which sometimes led to confusion and even hostility regarding the committee’s procedures and the safety of vaccines. Healthcare professionals and experts observing the meeting were left unsure about the implications of the committee’s decisions and how they might affect public access to Covid vaccines.

Regarding the issue of Covid vaccine prescriptions, the Advisory Committee on Immunization Practices (ACIP) was deeply divided, with a 6-6 vote. The tie was broken by the chair, Martin Kulldorff, who voted against the prescription requirement.

Additionally, the committee endorsed a recommendation for the CDC to “promote more consistent and comprehensive informed consent processes,” potentially highlighting six “risks and uncertainties” associated with Covid vaccines. However, it was unclear how this recommendation would be implemented. The concept of “individual-based decision making,” also referred to as “shared clinical decision making,” lacked clarity, particularly concerning how it would be applied differently based on age groups—specifically for those under 65 compared to those over 65.

The recommendations made by this committee influence which vaccines are supplied by the US government without charge, can guide state and local legislation on vaccine mandates, and affect which vaccines health insurance companies are likely to cover.

Now, the committee’s moves are sure to further complicate the already fragmented landscape of vaccine availability.

Significant shifts in the vaccine framework have occurred since Robert F Kennedy, known for questioning vaccine safety, assumed control of the US Department of Health and Human Services.

In August, the Food and Drug Administration approved updated versions of the Covid-19 vaccine only for people who are 65 or older or for people who have a medical condition that renders them high risk. That move unleashed widespread bewilderment over whether young, healthy people can still get vaccinated against Covid.

Some pharmacy chains, like CVS and Walgreens, said they would require prescriptions for the vaccine or cease offering them entirely in some states. Other states, including New York, moved to protect access to the vaccine for people who don’t have prescriptions.

Kennedy fired the previous iteration of the advisory committee and instead appointed several advisers who have little to no documented expertise with vaccines, or have criticized them heavily. That lack of experience came into focus repeatedly during the committee’s two-day meeting.

On Thursday, during the first day of the meeting, the committee voted to recommend that children receive multiple shots to protect against mumps, measles, rubella and varicella – or chicken pox – rather than a single vaccine. But afterward, when asked to vote on whether they would recommend that Vaccines for Children, a US government program that provides free vaccines to low-income children, continue covering the combined MMRV vaccine, many of the members seemed unsure of what Vaccines for Children was.

However, they initially voted to maintain Vaccines for Children’s coverage of the combined MMRV vaccine. Then, on Friday morning, the committee voted to reverse that vote and instead eliminate coverage for the combined vaccine.

The Friday meeting was punctuated by highly tense outbursts. A microphone caught one member calling another “an idiot”, although it wasn’t clear who was speaking. During one barbed exchange, one member demanded of another: “Show me that study!”

At one point, a member took the floor to announce that the discussions at the meeting had demonstrated that “we are not, as a committee, anti-vaxxers”.

A planned vote on the hepatitis B vaccine was also tabled after members pointed out inconsistencies in the wording of the vote and suggested that they would prefer to recommend delaying the hepatitis B vaccine until even later in a child’s life. Although voting had begun, the members ultimately decided to postpone the vote until at least their next meeting.

Experts who spoke to the committee at the meeting highlighted the members’ tendency to raise hypothetical situations, opinions and anecdotal experiences, rather than focusing on data that demonstrates the safety of Covid vaccines.

“Relying on case reports, anecdotes and selected basic science data – is that enough to justify a change in policy or a recommendation that limits an effective vaccine?” said Grant Paulsen, who spoke on behalf of the Pediatric Infectious Diseases Society.

“I would encourage the committee to make decisions based on the data rather than theoretical concerns that are raised. Those are certainly valid concerns – I’m not here to dismiss them. Continued monitoring, continuing research is vital, but really should not be a barrier to families looking to access this tool to protect their children.”