WHAT TO EXPECT WITH A COVID-19 VACCINE
Scripps Research expert explains what we know (and what we don’t) about how immunization might work
Masks. Stay-at-home orders. Shuttered businesses and schools. We’re all living in a new normal. But many people hope that a COVID-19 vaccine could return us to the old normal — or something close to it.
We asked Scripps Research vaccine expert Dennis Burton if that’s really possible.
Burton’s team of scientists is renowned for studying the immune responses of people living with HIV to find clues about how to design a vaccine. And now they’re doing the same for the novel coronavirus.
This conversation has been edited for length and clarity.
Q: You’re an HIV expert. After more than 30 years, we still don’t have an HIV vaccine. Is there any chance that this new coronavirus also ends up being extremely hard to come up with a vaccine for?
A: It’s very unlikely that the virus will present the same kinds of problems that HIV does. For instance, it does not seem particularly hard to induce neutralizing antibodies to this virus, based on preliminary studies. I don’t think this virus is in the category of very difficult pathogens to make vaccines for like HIV, malaria or TB (tuberculosis).
Q: How confident are you that we’ll have a COVID-19 vaccine by the end of the year?
A: What’s possible is that we’ll have a positive signal by the end of this year. So we would have pretty good evidence that one of the vaccines was inducing the right immune responses in a large number of people.
Q:
What do we mean when we talk about a vaccine working? What’s the goal? A:
A good vaccine prevents disease in a large fraction of individuals. It doesn’t necessarily completely prevent infection. I think if the vaccine reduced serious COVID-19 complications to symptoms of a common cold, that would be a huge success. If it reduced hospitalizations greatly, that would also be very good. And you’d like the vaccine to reduce transmission.
Q:
Some recent studies have suggested that the immune responses triggered by this virus don’t last very long — in some cases, just a few months. Is that concerning news for a vaccine? A:
Those findings wouldn’t necessarily apply to a vaccine. When you vaccinate, you can change the conditions of exposures to the virus to get a more durable response. Some people say that a vaccine can never do better than natural infection in terms of providing immunity. That’s not true. There are cases where vaccination does better. The shingles vaccine is a good example. And so is human papillomavirus, where natural infection produces a pretty weak response, but the vaccine is fantastic.
Q: There are some vaccines that we only get a few times in a lifetime. But others, like for flu, we get every year. Which category do you think a COVID-19 vaccine would fall into? A:
That’s very difficult to say. We don’t know how long the responses induced by the vaccines that are out there would last. That’s just data that we don’t have.
Q: Viruses change, or mutate, over time. Is that a major issue with this virus? A:
The virus is not varying tremendously. Though as soon as we put it under pressure by vaccinating millions of people, it’s possible there may be a new change. But if you have a good vaccine, you’re hitting the virus from multiple angles. And it’s hard to mutate away from that.
Q: How confident are you that any COVID-19 vaccine(s) would be safe? A:
You always want to be cautious with vaccines, because you’re giving them to large numbers of healthy people. So vaccines require a higher level of safety. But I expect these vaccines to be safe. Researchers test for safety throughout the whole clinical trial process.
Q: Could a vaccine really get us back to some semblance of normal? A:
Oh, it definitely could, but you need most people to get vaccinated. And in the United States, that’s a big question. There is quite a strong anti-vaccine movement, which could influence folks and prolong this pandemic.