US unlikely to have millions of doses of COVID-19 vaccine by fall
Scott Gottlieb, MD, former commissioner of the FDA, expressed doubt that necessary large-scale manufacturing of a COVID-19 vaccine would be available by the fall but was optimistic that inoculations could be available by 2021. Gottlieb discussed the COVID-19 pandemic and the country’s response to the virus at the virtual American Society of Cataract and Refractive Surgery meeting.
“Assuming that mass inoculations will begin at some point in a good case scenario of late 2021, not in 2020, then we’ll probably be vaccinating at the same point we vaccinate for flu season. I think flu vaccination rates are going to go up. Manufacturers have substantially increased supply of flu vaccine for this season by about 25%,” Gottlieb said during a discussion sponsored by Novartis Pharmaceuticals.
If an effective vaccine is available in 2021, many people will be simultaneously vaccinated for both the flu and the coronavirus.
Multiple companies with the ability to mass produce and scale doses are developing potential COVID-19 vaccinations. Johnson & Johnson and AstraZeneca are taking an adenoviral vector approach to a vaccine. A University of Oxford group published initial data from several monkeys treated with the vaccine, which appeared to not fully protect the animals from becoming infected but did stop them from developing full-blown pneumonia, Gottlieb said.
“It seemed to be protective from preventing pneumonia but not protective at preventing infection. That might be where a lot of these vaccines sell out, and that wouldn’t be that dissimilar from other vaccines that we have where they protect you from getting sick but they don’t fully protect you from getting an infection,” he said.
Pfizer and Moderna are both taking an mRNA approach, in which an mRNA construct is used to express a protein on the surface of the virus. This leads to the body developing antibodies, he said.
Sanofi is using its more traditional approach of developing a flu vaccine to develop a COVID-19 vaccine. Less is known about Merck’s approach to its vaccine, but it is believed it could be a similar approach to what the company used for its Ebola vaccine, he said.
“The fact that we’re using novel approaches as well as traditional approaches gives us multiple shots on goal in case some of these novel approaches don’t work or in case some of the traditional approaches don’t prove to be immunogenic enough,” Gottlieb said.
What will likely be available first is low-cost mass screening for the disease through pooled testing and the currently available polymerase chain reaction (PCR) testing.
“You might want to test in the workplace, have everyone spit in a tube, pool the samples in pools of 20 or 50 or 100, depending on what the background incidence is of the infection, and then test the entire pool. If you get a hit on a pool, you go back and individually test with PCR. If you can do that on a high throughput system on a low cost, it could facilitate mass screening on a more routine basis,” he said.
Additionally, new point-of-care tests coming onto the market, when combined with the PCR platform, will bring “literally millions of tests into the market each week,” he said.
- Gottlieb S. ASCRS Sunday Session: Discussion with Scott Gottlieb, MD, sponsored by Novartis Pharmaceuticals. Presented at: American Society of Cataract and Refractive Surgery meeting; May 16-17, 2020 (virtual meeting).