Of more than 100 vaccines in development globally, at least eight have started testing in humans, including candidates from Moderna Inc. and Pfizer Inc. At the same time, pharmaceutical giants like Johnson & Johnson, AstraZeneca PLC and Sanofi SA are building capacity to make hundreds of millions of doses of their own or their partners’ vaccines. The efforts are part of a larger rush, including at the White House, to line up funding for accelerated testing and expanded manufacturing capacity, all to make doses available in the U.S. starting as soon as this fall.
A safe and effective vaccine is the best way to prevent Covid-19, the respiratory disease caused by the new coronavirus, and to curb its transmission, public-health officials say. Drugmakers say they are developing potential coronavirus vaccines at remarkably fast speeds. Yet there isn’t a guarantee that any of the most advanced vaccine candidates will prove to work safely on such a short timetable. Some, like vaccines from Pfizer and Moderna, are based on relatively new technologies that haven’t been approved previously.
Once a vaccine is proved in clinical testing to work safely, drugmakers expect the U.S. Food and Drug Administration would move quickly to permit its use, even if the agency doesn’t have all the evidence it typically collects before granting an approval.
Several drugmakers that have been building up their capabilities to make coronavirus vaccines, have pledged to deliver millions of doses this year. Yet a fuller supply to vaccinate the general population might not become available until well into 2021, according to company projections and estimates by vaccine experts.
Public-health officials and vaccine experts hope more than one vaccine will cross the finish line, to boost the total number of doses available.
“Ideally we’d want seven or eight billion doses the day after licensure, so we can vaccinate the whole world,” said Walter Orenstein, associate director of Emory University’s vaccine center in Atlanta. “The likelihood is we won’t have enough to vaccinate even the entire U.S. population” when a vaccine first becomes available, he said. The prospect of limited initial supplies has triggered maneuvering over which countries get first dibs. Companies receiving U.S. federal grants, including J&J, Moderna and Sanofi, are expected to reserve some doses for Americans, according to industry officials.
Groups likely to be at the head of the line for access are front-line health-care workers and first responders, plus essential workers like grocery, pharmacy, food-supply and mass-transit employees.
Johnson & Johnson expects to have some batches of its vaccine ready by early 2021, which should be sufficient to vaccinate health-care workers globally. The company expects to eventually make more than a billion doses.
Moderna is expanding its vaccine production capacity, including via a partnership with Swiss contract manufacturer Lonza Ltd., to make tens of millions of doses a month by the end of this year, and eventually as many as one billion doses a year.
Drugmakers probably won’t seek to tweak or improve vaccines that enter distribution because that would require another regulatory approval.
Testing of early vaccines could show the way for subsequent shots, however, by giving researchers a better idea of the level of immune response needed to provide protection against the virus.
One open question is whether the elderly will benefit from a coronavirus vaccine since immune systems decline with age, which can reduce vaccines’ effectiveness in older adults.
Some of the uncertainty lies in the design of some early coronavirus vaccine trials, which enrolled healthy volunteers from 18 to 55 or 60 years old to get a quick read on safety in people more likely to endure any side effects.
“Older adults tend to have less robust immune responses to vaccines, so we can’t necessarily extrapolate what happens in younger adults to what might happen in older adults,” said Dr. Lisa Jackson, a senior investigator at one of the study sites for the Moderna vaccine, the Kaiser Permanente Washington Research Institute.
As of May 15th more than 100 vaccines are in development globally and at least eight have started testing in humans.
The National Institute of Allergy and Infectious Diseases recently expanded enrollment to include adults older than 55 to provide a truer picture in a continuing trial of the vaccine it co-designed with Moderna.
