After deploying four COVID-19 shots in just over two years, the nation is absorbing a troubling realization: It is a pace that is impossible to maintain.
In the last week, experts began to map a path to a future that is less perfect – but more practical.
That means building a vaccine that targets more than one virus strain. It would reduce serious illness and death, but not prevent any infection. If the design changes, all vaccines will be updated. Manufacturers are likely to offer the same vaccine formulation to everyone, rather than a mix of different products to different people on different schedules.
And the goal is to have it ready for next fall, when the risk of disease is likely to increase. It is a very tight deadline.
Faced with the triple threat of fading immunity, a developing virus and holiday gatherings, “we must be prepared, from a national security perspective, and ensure that we can protect our people with a vaccine in hand,” said Dr. Peter Marks an expert advisory FDA committee on Wednesday.
What will it look like?
“If we settle on a shot a year that combines COVID and the flu, I think it will be sustainable,” said UC San Francisco Infectious Disease Specialist Dr. Peter Chin-Hong.
“No one will want to get a vaccine every six months,” he said. “So we have to change the strategy.”
The creation and distribution of COVID-19 vaccines will go down in history as one of medicine’s greatest achievements. Only a year after the cases were first documented, a shot was available. Fifteen months later, an impressive total of four doses were available to many people: a two-dose primary series and two boosters.
But with each announced dose, interest decreases. While 77% of the eligible U.S. population has received one shot, this proportion drops to 65% who have received two shots and only 50% who have received three shots. The fourth dose has just started to be rolled out.
Vaccine protection is also fading. After each shot, our immunity follows the same disappointing downward trajectory. Vaccines, which are 91% effective in preventing hospitalization during the first two months, drop to 78% after four months – and over time they continue to decline.
This means that people who got their one shot back in early 2021 are becoming more and more vulnerable.
Funding will also disappear. Today’s federal funding free-for-all strategy will not go on indefinitely, experts predict. The costs will be transferred to private insurance companies. It puts pressure on efficiency and effectiveness.
Yet the virus has come to stay. And that will continue to change. The virus has mutated two to 10 times faster than the flu, depending on the strain, reported virologist Trevor Bedford of the Fred Hutchinson Cancer Research Center in Seattle. He said it will continue to mutate a little or a lot – either is possible.
To begin with, experts hoped that a three-dose regimen would provide long-term protection. That strategy works for measles, mumps, rubella, hepatitis B, HPV and other viruses.
But COVID is different because it is changing more, Chin-Hong said. This creates particular challenges for vaccination planning.
That means things have to go fast. The FDA hopes to take a position on the composition of a future vaccine in May or June. While some clinical trials of potential products are already underway, vaccine manufacturers need several months to produce enough doses of a reconfigured vaccine, according to Robert Johnson, director of the Infectious Diseases Department of the Department of Health and Human Services.
The panel agreed on these points:
The promise of a new “bivalent” or “multivalent” vaccine.
There is a declining return by repeatedly giving the same “monovalent” vaccine, which is targeted at the original strain, especially as new variants emerge. It also seems unlikely that an omicron-specific booster is the best idea. The virus changes so often that it can quickly become obsolete.
A better approach might be to design something that targets two or more virus strains, called a “bivalent” or “multivalent” vaccine. Such vaccines are already in use at Moderna and Novovax.
“A multivalent vaccine will be important to hopefully extend the duration of protection,” said Dr. Mark Sawyer, Professor of Clinical Pediatrics at UC San Diego.
• Therapy must play a growing role.
Instead of constantly adding vaccines, we should seek the help of antiviral drugs, monoclonal antibodies and other future therapies to treat infections to keep people away from hospitals.
With 80% protection against hospitalization in older and sicker adults, “I think we may have to accept that level of protection and then use other alternative ways to protect individuals with therapeutic and other measures,” said Amanda Cohn from the US Centers for Disease Control. and Prevention.
• Assume a more holistic approach to manufacturing.
Vaccine manufacturers should target the same strains using similar doses, panelists said. It will prove impossible to keep track of several vaccines with different compositions.
The CDC must take the lead in deciding when the vaccines are no longer effective against serious illness, said Dr. Paul Offit, Professor of Pediatrics at The Children’s Hospital of Philadelphia. “At some level, companies are dictating the conversation here,” he said.
If a new vaccine is needed to respond to a frightening variant, it will not just be a booster. The entire two-dose “primary series” would be replaced.
• There is a need for better data and new designs.
Because we are busy, we depend on what the data tells us about the immune response in blood. But we also need to become better at interpreting what these laboratory tests mean for protection in the real world, said Dr. Hayley Ganz, Professor of Pediatrics at Stanford University Medical Center. Antibody numbers are important, she said. But so are other parts of the immune system, as well as clinical outcomes.
Finally, we need to know what future products await us in the research pipeline, even though they have not yet been approved by the FDA.
“Current mRNA vaccines are amazing. They can be reversed quickly,” said infectious disease expert Dr. Ofer Levy of Boston Children’s Hospital. moving forward, we do not want to bake in a system that excludes other types of vaccines. ”