First single-shot, "fridge stable" COVID-19 vaccine approved in US
The U.S. Food and Drug Administration (FDA) has approved a third COVID-19 vaccine for emergency use in the United States. Unlike the first two vaccines approved for use, this one is proven effective after only a single dose, and it can be safely distributed in standard refrigerator temperatures.
The emergency use authorization (EUA) from the FDA follows on from two prior approvals for Pfizer's and Moderna’s mRNA-based COVID-19 vaccines. This new vaccine, developed by pharmaceutical company Johnson & Johnson, is called a viral vector vaccine and it works a little differently to the mRNA candidates.
This approach utilizes a harmless adenovirus, engineered with genetic instructions that direct infected cells to produce the SARS-CoV-2 spike protein. Once a body begins producing these foreign proteins the immune system learns how to fight back and immunity is generated. The adenovirus used as a delivery device in the vaccine has been genetically modified so it is unable to replicate or cause any disease.
The Vaccines and Related Biological Products Advisory Committee, an independent panel convened by the FDA to evaluate the vaccine, unanimously voted to recommend an EUA for all adults over the age of 18.
Pooled data from several trials around the world, encompassing over 40,000 subjects, suggest the J&J vaccine is strongly effective at preventing moderate to severe disease four weeks after a single dose. Unlike the previously approved vaccines, this candidate was trialled in countries such as South Africa as new SARS-CoV-2 variants were emerging.
Protection from moderate to severe disease slightly varied across different regions, from 77 percent in the US trials to 57 percent in the South Africa trials. But most importantly, the single-shot vaccine conferred 100 percent protection from hospitalization and death in all trials, regardless of region.
“After a thorough analysis of the data, the FDA’s scientists and physicians have determined that the vaccine meets the FDA’s expectations for safety and effectiveness appropriate for the authorization of a vaccine for emergency use,” says Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research. “With today’s authorization, we are adding another vaccine in our medical toolbox to fight this virus.”
The J&J vaccine stands apart from the previously approved Pfizer and Moderna vaccines, which both require two doses administered several weeks apart to confer complete protection. All testing so far with the J&J vaccine suggest it offers protection 28 days after one-shot, making it significantly easier to vaccinate large volumes of people from a logistical standpoint.
The other major benefit to the J&J vaccine is it can remain stable and effective for up to three months at standard refrigerator temperatures (36-46°F/2 to 8°C). This makes the vaccine significantly easier to deliver to remote regions.
“We believe the Johnson & Johnson single-shot COVID-19 vaccine is a critical tool for fighting this global pandemic, particularly as it shows protection across countries with different variants,” says Paul Stoffels, Johnson & Johnson’s chief scientific officer. “A vaccine that protects against COVID-19, especially against the most dire outcomes of hospitalization and death, will help ease the burden on people and the strain on health systems worldwide.”
The company claims 20 million doses will be available in the US by the end of March, and 100 million doses by the end of June. An emergency use application has also been submitted to the European Medicines Agency.