August 11, 2020
Your COVID-19 vaccine questions, answered
BY Cynthia DeMarco
Last updated Dec. 2, 2020
As coronavirus (COVID-19) cases continue to rise, more people are wondering when we’ll have a vaccine — both to protect themselves and their families from infection and to create herd immunity so that life can return to a more familiar rhythm.
But is there a vaccine available yet for the coronavirus? If not, how long will it take until there is a COVID-19 vaccine? And how quickly can cancer patients and their families expect to get it?
We spoke with infectious diseases specialist and head of Internal Medicine David Tweardy, M.D., for details.
Is there an FDA-approved vaccine available right now for the coronavirus?
No, there is not an FDA-approved COVID-19 vaccine yet.
But there are more than 150 candidates for a coronavirus vaccine in the works and at least a dozen major pharmaceutical companies involved in their development here in the United States.
Two vaccine candidates are already in Phase III clinical trials. That means they’ve already been vetted for safety and the ability to induce antibodies against the virus, and now they’re just trying to nail down the dosage and demonstrate that the antibodies generated protect a person against infection.
News reports indicate that other countries might already have a vaccine. How reliable are those? And will they be made available in the United States?
There have been some reports that Russia is now providing a vaccine to health care workers, but it’s important to clarify that it’s without the benefit of a Phase III clinical trial. It’s difficult to assess the quality or reliability of their vaccine from the information available, but even with all the data, I suspect it would be unlikely to pass muster under current Food and Drug Administration guidelines. Vaccines that are produced entirely outside the U.S. (e.g., in China and India) would be available primarily to people living in those countries.
What are the types of coronavirus vaccines being developed in the United States?
There are four different types being developed that are in the lead. One involves deactivated virus. The second uses RNA from the coronavirus. The third uses a carrier virus (such as an adenovirus) containing part of the coronavirus’ DNA. And the fourth uses a single protein from the tip of the spikes that cover the coronavirus.
How do these COVID-19 vaccines work?
They all work slightly differently.
The first is the most old-fashioned and the least sophisticated. It involves injecting people with virus that’s been inactivated (or made harmless) through heat or some other means. This causes a very broad immune response in the recipient, but not necessarily the one you want.
The second and third methods target the really important part of the virus — the protein spikes that stick up like little maces all over its surface — instead of the virus as a whole. Both prompt the body to generate the spike protein itself. Once that happens, the immune system recognizes it as an invader and starts developing antibodies against it. So, when the real coronavirus comes along, these antibodies can shut it down. This is the strategy that most of the vaccine makers are pursuing right now.
The fourth method involves injecting people with the spike protein itself, instead of pushing their bodies to generate it.
All three of these last approaches have been used successfully, based on the studies done so far. The fourth one is just not quite as far along in testing as the RNA and carrier approaches are.
What makes the RNA-approach so different from that of previous vaccines?
This is the first time this type of technology has ever been used for a vaccine. And the speed at which it is being developed is truly mind-boggling.
Remember, this particular coronavirus was virtually unknown in November 2019. The actual syndrome caused by it was only first described in December 2019. A month later, scientists had isolated the virus and sequenced its genome. That’s something that used to take a full year or more. Two months later, we had the first COVID-19 vaccine candidates. And four months after that, some were already in Phase III clinical trials. So, we might well have a coronavirus vaccine available to give to high-risk individuals by late 2020 or early 2021.
That’s only 10 months from the first time this particular coronavirus was identified, which is unheard of. Vaccines have not been developed at this speed before. I’ve been working in infectious diseases for 40 years, and I never would’ve thought it was possible. But success is seeming increasingly likely.
Could this same vaccination method be used again against future coronaviruses?
Absolutely. This strategy has the capacity to almost let us anticipate the next strain of coronavirus so we can be prepared for it, kind of like we do now with the flu.
We could sequence the next coronavirus that’s identified as distinct and separate from this one in a month or less. Once we had that, we could insert the sequence of its spike protein into every step of the vaccine development pathway. That could get us another vaccine within three months.
With this family of coronaviruses, that could potentially allow us to have a vaccine ready before the next one even becomes a pandemic. So theoretically, we could stop the next pandemic in its tracks.
How long do you think the coronavirus vaccine will be effective?
Well, we’d obviously love for it to give lifelong immunity against COVID-19, but that remains to be seen. If I had to guess, I would say it’s probably going to fall somewhere between influenza and the mumps, in terms of longevity of protection. It will probably be closer to the flu, because respiratory viruses don’t tend to lead to long-term immunity.
One good sign is that in the Phase I and II clinical trials for the coronavirus vaccine, participants have been developing a very good level and quality of antibodies after receiving doses on day 1 and day 28. It’s at least as high as those seen in people who have recovered from an actual infection. So, I don’t think people will need a COVID-19 booster vaccine every year, but maybe somewhere between every one and five years.
Will the coronavirus vaccine be safe?
Yes. I think anyone who gets a coronavirus vaccine can have confidence that it will be safe. Otherwise, it wouldn’t be approved. The Food and Drug Administration will be looking at this very carefully, and the vaccine will have to be tested on a lot of people before it is made widely available.
Should I be concerned when I hear that a vaccine trial has been paused?
No. It’s fairly common for studies to be stopped temporarily. This gives researchers time to determine if any serious adverse events people experience are due to the vaccine or caused by something else.
Even during a pandemic, life goes on, so people can still become ill for any number of reasons. If researchers determine the adverse events are unrelated to a vaccine, then studies can be restarted. This has occurred in the case of one big COVID-19 vaccine trial; the pause was lifted and the trial restarted after a one-week review by independent trial safety experts determined that the adverse event was unrelated to the vaccine. Also, with three or four companies all on track to produce large quantities of the vaccine once it’s approved, people will have many options to choose from. That means we’ll all able to get vaccinated more quickly and be moving toward herd immunity that much sooner.
Is safety a concern if a vaccine gets pushed through with an Emergency Use Authorization prior to completion of the clinical trials?
I can’t recall an instance in which EUA approval was given to a vaccine, so I don’t think it’s very likely now, and certainly not for broad distribution to the public. But even if it were to happen, I think circumstances would have to be very different from what they are today.
I can imagine a scenario in which persons at highest risk may be eligible for vaccination under an FDA-granted EAU, including health care workers and first responders, while data was continuing to be collected in the ongoing late-stage clinical trials. But full evaluation by the FDA of the data from these completed trials would be required before the vaccine would be made available to the general public.
So far, the FDA has only given EUA approval for diagnostic tools (such as saliva tests) and possible treatment options, such as remdisivir, an antiviral medication.
Once a coronavirus vaccine is approved, how quickly will it begin to get distributed?
The initial supplies of vaccine are anticipated to be in the 10 to 20 million dose range. It appears likely they will be available the week of Dec. 14, 2020, for administration to health care workers and nursing home residents.
I would anticipate the coronavirus vaccine being available a month or two later for elderly individuals, since they, like nursing home residents, are one of largest groups at risk for serious consequences.
Why should cancer patients get the coronavirus vaccine?
Because cancer patients are at higher risk of developing a serious infection and complications than someone without cancer. And cancer patients are more likely to require hospitalization if they catch the coronavirus. So, they would be in a better position to benefit from a vaccine.
Should cancer patients get the coronavirus vaccine as soon as it becomes available or wait?
I would say to take it as soon as they can, but speak with their physicians first.
The side effects in the Phase I and II clinical trials thus far are very typical of the vaccines I’ve taken my whole life, such as the flu vaccine that I get every year. And people have every reason to expect that any FDA-approved vaccine will be safe and based on sound data.
Why will it be important for everyone — including healthy individuals — to get the coronavirus vaccine?
Getting the coronavirus vaccine will help build herd immunity and protect ourselves and others — including the most vulnerable members of our community — from the coronavirus.
I know some people worry about possible side effects of vaccines. Every vaccine has a risk of minimal side effects, such as inflammation or soreness at the site of the injection. But those are completely outweighed by the risk of getting COVID-19 and having a bad outcome. That is several orders of magnitude more likely than having a bad outcome from a vaccine.
If a vaccine meets the usual standards, then it is approved and safe. And the risk of not getting the vaccine and getting COVID-19 and spreading it to others is much higher.
- When will we achieve herd immunity?
- What counts as COVID-19 exposure?
- Can air purifiers protect you from COVID-19?
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The speed at which it is being developed is truly mind-boggling.
David Tweardy, M.D.