In 2020, and again in 2021, the dreaded pandemic never came. The concern among experts has been that a winter coronavirus surge over flu season — or even, in the worst-case scenario, a flu outbreak of pandemic proportions — would push already strained hospitals over the edge. Fortunately, we got lucky. Flu season simply did not materialize in 2020: only the US recorded about 2000 cases, 110 times less than in the previous season. Similar trends exist for other respiratory viruses. In 2021, cases From 2020, but it’s still well short of typical pre-pandemic years.
Now it looks like our luck has finally run out. Flu season has just begun, and the US has already scored Explosion cases. A massive wave of respiratory syncytial virus is hitting the country, along with smaller parallel spikes in rhinovirus and enterovirus. The result of all this is what my colleague Catherine J. woo Call “The worst child care crisis in decades.” Meanwhile, COVID cases and hospitalizations remain low across the country compared to the early stages of the pandemic, but the coronavirus continues to kill about 350 Americans a day. Anxiety now is not a double epidemic but “three times. “
What this means for you is that your body is likely to encounter many different viral enemies this season — perhaps even at the same time. When you board a plane, watch a show, or eat outside, you are faced with a downward spiral of viruses that are more diverse than they have been in recent years. How do you expect your body to adapt?
Before delving into the pillars of immunity, it’s worth making one thing absolutely clear, at the risk of making the obvious: catching a cold won’t protect you from COVID. COVID will not protect you from the flu. Nor the flu from RSV. Different viruses penetrate the body’s defenses in different ways, and unfortunately, as impressive as our immune system is, it doesn’t have some universal ability to fend off all seasonal pathogens just because it detects one. The same goes for vaccinations. The flu vaccine will not vaccinate you against COVID, and the COVID vaccine will not vaccinate you against the flu; Defense against both viruses requires both vaccines.
immune system he is Notoriously complicated, however. As my colleague Ed Young wrote, Immunology is where intuition dies. When people’s bodies encounter two different pathogens, either simultaneously or in quick succession, all kinds of dynamics influence it. And still more confusing, these dynamics can vary greatly from person to person. Some people have conditions that make them immunocompromised. Others must take immunosuppressive medications. Genetics Come to play. Playing factors that no one yet understands.
When a pathogen finds its way into your body, the initial stages of the response are part of what’s called the innate immune system — a collection of cells, barriers like skin, and cough-like reflexes that work collectively to fend off foreign invaders. The innate immune system is not particularly special. He only distinguishes between what is part of the body and what is not, and then attacks the latter. Infection by one pathogen is unlikely to enhance the response of the innate immune system to the other in anything but the most marginal way. “You may be a little bit fast-moving, and your immune system may work a little faster, but there’s no specific protection,” Cornell University immunologist Cindy Leifer told me. “You would still get the whole infection. It might be a little less severe.”
These secondary benefits, if you get them at all, she said, will likely only last a week or two. Even they are far from the data. In fact, one disease can sometimes leave you more I’m at risk of contracting another one, Annabelle de Saint-Maurice, M.D., a pediatric infectious disease specialist at UCLA Health, told me. The flu, for example, can increase your risk of developing some bacterial infections. Covid disease can increase your risk of some types of fungal infections. At this point, it is difficult to determine how COVID interacts with other respiratory viruses. Since we’ve seen very few cases of these other viruses over the past few years, we don’t have a lot of samples from which to infer.
As the innate immune system slows down, the body mobilizes B cells and T cells, which, unlike cells involved in the innate immune response, come in many specialized varieties to fight many different pathogens. These cells are part of the adaptive immune system, and are distinguished from the innate response by both this specificity and their ability to memory. Once the pathogen is removed, a portion of the B and T cells that are called into action stick so that if the body encounters the same pathogen again, it can move on more quickly and more forcefully than it did the first time.
In some cases, the adaptive immunity conferred by one pathogen can protect us from another disease. This is called cross-immunity. If two pathogens are similar enough, the immune system may build protection against one by fighting the other. We sometimes see this with different strains of influenza. or different COVID variants. This is why smallpox vaccines can vaccinate against monkeypox. Early in the epidemic, some scientists supposed Previous infections with the common cold coronavirus that are familiar to all of us may provide a degree of protection against COVID. Some studies have provided modest support for this theory, but the real-world results — millions of deaths from COVID-19 — suggest that whatever protections we had weren’t terribly strong, Donna Farber, an immunologist at Columbia University, tells me.
The way you play the cross-play can differ drastically from person to person. The response depends on the adaptive immune system’s perception of the portion of pathogen A shared by pathogen B. It is this matching that allows the body to mount an immune response to pathogens B, even though it has not been encountered before. If the body instead recognizes a part of pathogen A that is not shared by pathogen B, the body will not initiate a cross-reactive response. Researchers are trying to understand why these dynamics somehow occur in one person and occur differently in another, but for now, Leifer tells me, “I don’t think we really get along well with that.”
She said that when an object hits a near perfect match between parts of two viruses that aren’t that similar, it’s “like winning the lottery.” Unless you like these possibilities, you probably shouldn’t rely on cross-immunity to save you from this flu season. Instead, the fact is that you are more likely to catch different things this winter than you were in the past or the one before. be safe there. Immune superpowers can only provide a great deal of protection.