While clinical trial data is not clear on how this change to the tested dosing schedule will affect long-term immunity, the JCVI advice presents a utilitarian solution to the current wave of virus transmission spreading across the UK. “The four UK Chief Medical Officers agree with the JCVI that at this stage of the pandemic prioritising the first doses of vaccine for as many people as possible on the priority list will protect the greatest number of at risk people overall in the shortest possible time and will have the greatest impact on reducing mortality, severe disease and hospitalisations and in protecting the NHS and equivalent health services,” declares a UK government statement.
In response to the UK government decision, the US Food & Drug Administration released a statement claiming it does not recommend changes to currently approved COVID-19 vaccine dosing schedules, and called any changes to dosing schedules, “Premature and not rooted solidly in the available evidence.”
The FDA’s statement claims there is no data from clinical trials to suggest anything definitive about the depth or duration of protection one would receive from a single vaccine dose.
“We know that some of these discussions about changing the dosing schedule or dose are based on a belief that changing the dose or dosing schedule can help get more vaccine to the public faster,” the FDA statement notes.
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in an interview with CNN the US will not be following the UK in delaying a second dose for COVID-19 vaccines.
“Depending on the duration of protection conferred – and, of note, considering only a six-month time horizon – a single-dose vaccine with 55 percent effectiveness may confer greater population benefit than a 95 percent-effective vaccine requiring two doses,” the new research notes.
So what’s the harm in delaying the second vaccine dose? Paul Bieniasz, a virologist from Rockefeller University, expressed perhaps the biggest concern regarding the UK decision to change its vaccination schedule.
Bieniasz described delaying the time between a first and second vaccine dose as the perfect way to “Generate vaccine-resistant SARS-CoV-2 variants.”