The benefits of hybrid immunity and daring to return to the office: COVID Quickly, section 28
Lewis asked: Hello and welcome to COVID, Fast, a Scientific American pod series.
Josh Fischman: This is your quick update on the covid pandemic. We inform you about the science behind the most acute questions about the virus and the disease. We demystify the research and help you understand what it really means.
Lewis: I’m Tanya Lewis.
Fischman: I’m Josh Fischman.
Lewis: And where Scientific Americans senior health editors. Today we will talk about how vaccines increase immunity even if you have already been infected …
Fischman: … and how to manage to go back to the office, even if covid is still there.
Lewis: Many unvaccinated people think that if you got covid once, you are completely protected from getting it again. But it is not true. Can you explain?
Fischman: You’re talking about the idea of natural immunity, that one early infection prevents another. It turns out that this is not the best protection you can get. What seems to be better is something that researchers call “hybrid immunity.” It is a natural infection plus a whole course of vaccines. Three new studies support this idea.
Now a previous infection helps. An article just published in the magazine Lancet Infectious Diseases looked at people in Sweden who were once infected. They had a lower risk of another infection, compared to people who had never been infected or people who had not been vaccinated.
But this is where it gets interesting. Add vaccination in addition to the early infection, and it improved protection by 50 percent. It also kept that protection strong for another six months.
It is linked to a long-term study in England, which tracked people for more than a year. It appeared in the New England Journal of Medicine. Early infection prevented 80 percent of other infections that would otherwise be expected. It is quite good. But adding vaccines further improved that protection, by almost 100 percent.
Finally, a study in Brazil found that people who had become infected and then received 2 doses of vaccine avoided 65 percent of the new infections you would normally expect and 80 percent of severe covid cases. So infection alone does something, but adding vaccines does a lot more.
All of this raises the issue of Omicron. I’m wondering, Tanya, if an infection with the original Omicron, BA.1, prevents you from getting BA.2, the sub-variant now circulating?
Lewis: That is a good question. In a new story, SciAm contributor Charlie Schmidt reports that early studies suggest that re-infection with BA.2 after BA.1 is possible, but rare. “If you were infected with BA.1, then you are probably well protected from BA.2,” Stephen Griffin, a virologist at the University of Leeds School of Medicine in England, told Charlie. But that protection may not be complete, Griffin said.
Countries that had large BA.1 peaks, such as South Africa, have so far not seen a large BA.2 peak. Once again, the UK had a large BA.1 increase and still saw a remarkable peak in BA.2 infections several months later. But it may have more to do with the fact that it released all COVID restrictions, so people who had avoided being infected in the previous wave may have become ill later.
We are already seeing an increase in infections in parts of the United States, especially in the Northeast. Whether it will lead to another wave or just a small bump remains to be seen. The good news is that many people will have some immunity to infection, vaccination or both.
Fischman: So our company just announced that it is reopening the office. Everyone is expected to show up. And with covid still nearby, I’m not super comfortable with crowds. Are you?
Lewis: Not especially. I have been quite careful throughout the pandemic, avoiding most indoor places except important ones like the grocery store and wearing an N95 or KN95 mask when I am indoors. So the thought of going back to the office regularly, especially without a wormhole, makes me a little nervous.
Fischman: Are you not vaccinated and boosted though?
Lewis: I’m not very worried about getting very sick myself. But I worry about spreading the virus to others who are more vulnerable. I actually have an immunocompromised family member that I visit from time to time. In addition, there is a risk of long-term covid. But I’ll probably go into the office a couple of days a week and just wear my N95. How are you?
Fischman: Yes, I’m with you on the masks. People who work in retail, in grocery stores and restaurants, wear them because they are dealing with a stream of different people throughout the day. So I will do the same.
I also want to keep an eye on the spread of society. The CDC has a tracker for this, called “COVID-19 Community Levels.” You can Google it. It looks at both new cases and hospital stays per country, and uses these to describe areas such as low, medium or high spread.
Lewis: So, how do you intend to use that information?
Fischman: If my area becomes medium or high, I will use a mask even more often. But it’s just weird to look at statistics that show that cases are starting to increase and then hop on a crowded train to go to a crowded office. Is it not?
Lewis: Yes, it’s nervous. Although MY risk of getting seriously ill from covid is quite low, it does not mean that I want to get it if I can help it, especially considering that we can go into another increase. But does the CDC tracker miss any important information, Josh?
Fischman: True. That tracker is also too desirable when it comes to wearing a mask in “medium-sized” risk areas.
Lewis: Right. And according to the CDC, Manhattan is already considered a medium risk. For now, I will continue to use my toolbox with precautions. In addition to wearing a good mask, I will continue to keep my distance from people on the train whenever possible and avoid cramped areas in the office.
Fischman: What do you think of our place? Does it have good airflow?
Lewis: Our office has no windows that you can open, but it has a decent MERV filtering system. But even with these precautions, there is still some risk, and you can not help but feel a little worried, right?
Fischman: Anxiety is okay. I mean, this virus has killed 1 million Americans in two years. Now we seem to be in a world filled with nails and dips. We know much more about how we can stay safer today. If we all act on that knowledge – like doing some of the things you do – maybe I and many other people will start to feel comfortable.
Lewis: Now you’re up and running. Thank you for joining. Our show is edited by Tulika Bose.
Fischman: Come back in two weeks for the next episode of COVID, fast! And check out SciAm.com for updated and in-depth COVID news.
[The above text is a transcript of this podcast.]