Many experts are saying that social distancing may have to continue until we have a COVID19 vaccine. That may not necessarily mean we have to stay home, but it does mean we may need to continue wearing masks and banning large public gatherings for the next year or more. So let’s talk about why vaccines are important, the status of a COVID vaccine, why it can take so long, and what might happen if we don’t get one.
Why is a COVID19 vaccine so important?
Vaccines are the best remedy against viruses.
First, they prevent infections–meaning that the virus doesn’t have a chance to reproduce and spread in the first place. If we prevent a virus from infecting people, we don’t need medicine.
Second, making drugs that can stop a virus infection (antivirals) is difficult. This is because viruses are very simple parasites. Most of what they do involves hijacking cells to make more of themselves. Because they use your body to do their thing, there aren’t many ways to interfere with their lifecycle without harming your body, too. This is different from bacteria. Bacteria are more complex life forms, so we can create drugs (antibiotics) that stop their unique parts from working.
What’s the current COVID19 vaccine status?
In a nutshell: a vaccine is in development, but is very likely to take at least a year. That’s because research is still in the early stages. There is a vaccine in clinical trials (being tested in people), but it sounds like researchers don’t expect this early candidate to be “the one”.
The 12-18 month timeframe is actually very quick for a virus that is brand new. Even the flu vaccine takes 6 months to develop and produce, and we already have a tried-and-true system in place for making large batches of it. We don’t have such a system for making large batches of coronavirus vaccines. We don’t even have a great candidate yet for a vaccine. We do have leads, though.
There are two coronavirus that have previously caused outbreaks and serious illnesses known as SARS and MERS. After the SARS outbreak in 2003, scientists started the research to understand how these deadly coronaviruses caused infection and how the immune system might react. So, even though COVID19 is caused by a new coronavirus, the research on SARS and MERS gives us a head start.
How are vaccines made?
As I mentioned, the time consuming part of making a vaccine is collecting data. By data, I mean the results from numerous tests. We can’t make these tests faster, but we can have a bunch of labs doing different tests at the same time. So, something like 70 – 100 different vaccine candidates are being tested in various labs right now. From there, it comes down to weeding out a few of the most promising candidates to move forward with.
How do they know when they have a good candidate? A good vaccine must cause a strong “immune response,” which usually means that antibodies are created. Other immune responses may be effective as well, but the immune system is very complicated, so I won’t (can’t really) elaborate further (see Fundamentals of Vaccine Immunology). Antibodies are important Y-shaped proteins that can stick to a virus, prevent it from getting into cells, and tell the immune system to destroy it.
To find out whether the vaccine candidates create a good immune response, scientists inject them into lab animals (such as mice, rats, or primates); later, the scientists test the response. They will collect the animals’ blood to see whether there are antibodies there, and they will infect the animals with virus to see whether they get sick.
Why do the clinical trials take so long?
If everything works as predicted, the order of things will look like this:
- First, potential vaccine candidates are tested as described above, which they say this will take 3-6 months. This is happening now.
- The next step is safety testing in humans (these are called phase I clinical trials). For these tests, scientists test differently sized dosages of the vaccine to make sure they don’t have side effects.
- After that test, they do a next round of testing in a larger group of people. These tests (phase II clinical trials) further monitor the vaccine’s safety and alo check whether the vaccine causes an immune response. The data from this type of study is used to plan the next phase.
- Next would be a phase III clinical trial, with larger groups of people, more close monitoring for side effects, more evaluating of immune response, and likely lots of monitoring of subjects’ health and activities to see whether they are exposed to the virus and whether they get sick.
I’ve heard that they are likely going to be doing some of these phases in an overlapping way to get data more quickly in this unique situation. However, no matter what steps they skip, scientists still must collect enough data to convincingly show that the vaccine is safe and effective before it will be approved by the FDA. Only then can it go into production.
So, this whole testing phase is what may take 12-18 months. But then production will have to be figured out, so that will also take time – months, likely.
What if we don’t get a vaccine?
With all of this to think about, it is still possible that we don’t get a vaccine in that time. Some things in science and nature are just stupidly tricky. The coronavirus that causes COVID19 seems likely to continue to spread and cause local outbreaks for the next year or so. Many people will contract it, over time, which will likely provide them at least some immunity. Eventually the spread may slow down, as population immunity increases. Unfortunately, it is possible for the virus to mutate and begin to dodge that immunity, like the flu virus does. But, that virus will be different, and may not be as severe or spread as easily.
There are many possibilities. But I’m optimistic that we will go on with society and culture for the next year, even if it’s a little different. They may implement contact tracing to do so. Maybe antibody testing will improve. We will learn to not touch our face, we will carry/provide hand sanitizer everywhere, we will wash our hands well and often, and we will get used to wearing face masks in crowds, especially when we have a cough or tickle in our throat. There are so many people working on solutions, and I think the right attitude is openmindedness and willnessness to listen to health experts.
Maybe I’ll do another post soon about possibilities for what the immediate future might look like.