The Moderna vaccine is the second most recommended for emergency use permit in the United States.Credit: Paul Hennessy / NurPhoto / Getty
A week after U.S. regulators approved the country’s first coronavirus vaccine, a panel of outside advisers has voted for a second: another RNA vaccine, manufactured by Moderna of Cambridge, Massachusetts.
The vote on December 17, which was unanimous by one voter, is seen as a final hurdle for the Moderna vaccine, and is expected to be granted emergency use by the U.S. Food and Drug Administration (FDA). . One week earlier, a similar vaccine group authorized Pfizer in New York City and BioNTech of Mainz, Germany, authorized it about a week after UK regulatory authorities did the same.
The speed of these authorities reflects the speed of the pandemic, and is a testament to the scientific advances that have rapidly developed vaccination, said psychologist James Hildreth, president of the College. Meharry in Nashville, Tennessee, at a panel meeting Thursday. “Going from a series of viruses in January to two vaccinations in December is a remarkable achievement. ”
The authorization will initially be for Moderna, a ten – year – old biotechnology company that has pledged to reverse treatment by using RNA as a therapeutic agent, but has not yet pushed a drug or vaccine through to the clinic. It joins a growing list of organizations with coronavirus vaccines in use around the world, including teams in China and Russia.
In the United States, the vaccines offer a glimmer of hope amid the prospect of a harsh winter. The country records thousands of deaths from COVID-19 every day, and this is expected to rise over the winter holiday season. Coronavirus infections are so rampant that Moderna was able to reach the top of the test field five months earlier than expected, said Jacqueline Miller, senior vice president and head of infectious diseases at the company.
RNA vaccine
The Moderna vaccine, developed in collaboration with the U.S. National Institute of Allergy and Infectious Diseases, works in the same way as the one made by Pfizer and BioNTech. Both are composed of closed RNA molecules in lipid nanoparticles. The RNA in all vaccines encodes a slightly altered form of the SARS-CoV-2 protein called spike, which allows the virus to infect human cells.
Once taken by cells, the RNA is used to secrete the protein, which then stimulates an immune response. The RNA does not enter the nucleus where the cell’s genome resides, and is depleted by the cell within a day of injection.
Like the Pfizer vaccine, the Moderna vaccine appears to be very effective – around 94% – in preventing the infectious diseases of SARS-CoV-2. Its safety profile is also similar to Pfizer’s, with fatigue, headaches and pain at the injection site being among the most commonly reported side effects.
Since the introduction of the Pfizer vaccine in the United Kingdom and the United States, there have been occasional reports of recipients experiencing a severe allergic reaction called anaphylaxis after taking it. be injected. There have been no signs of such reactions so far in the Moderna trial, which eliminated people who had previously received anaphylactic reactions to vaccines, but not those with other allergies, such as food allergies. .
The two vaccines differ in the combination of the lipid nanoparticle that surrounds the RNA, and the Moderna shape allows the vaccine to be stored at a higher temperature than Pfizer, which must be maintained at −70 ° C, much colder than a conventional freezer. The Moderna vaccine can be stored in a −20 ° C freezer for 6 months, and in a refrigerator (at around 4 ° C) for 30 days. This promises to speed up the use of the vaccine, especially in rural areas and in countries with limited healthcare infrastructure.
Continuous tests
FDA advisors spent much of a Dec. 17 committee meeting discussing when and how vaccines should be offered to participants in the placebo branch of the Moderna trial after an emergency use permit was issued. Once a coronavirus vaccine is available, participants can choose to leave the trial to ensure they receive an injection. Maintaining the integrity of clinical trials after a vaccine license – to collect data on long-term safety and duration of protection – is a major challenge for developers.
Last week, Pfizer suggested that when participants become eligible for a vaccine as part of a national rollout, researchers will tell them whether they have received the vaccine or a placebo. Moderna has instead recommended disconnecting the entire test at once after obtaining an emergency use permit, telling all participants what treatment they received, and offering vaccinations. those in the placebo arm using set-aside doses for the clinical trial.
Some FDA advisers warned that this approach would sacrifice valuable weeks of data collection, and allow some participants to get the vaccine ahead of others in equally priority groups in communities. . Others argued that while the approach is not particularly appropriate, it may be necessary given the complexity of vaccine distribution in the United States, where individual and local governments will be involved. setting their own priorities. “It’s so attractive here, it’s inconvenient,” said biostatistician Jeannette Lee of the University of Arkansas for Medical Sciences in Little Rock.
Offering trial participants the vaccine could help the company keep them registered in the study, so that it can continue to collect safety and immunity data, said Lindsey Baden, an infectious disease expert at Brigham and the Women ‘s Hospital in Boston, Massachusetts, who was asked by Moderna to discuss the matter with the committee. Some health care workers who took part in the trial were already leaving to receive the Pfizer vaccine, he said. “If we lose our volunteers the opportunity to learn anything else will be greatly weakened,” he said. “We have to be practical.”