I’m a virologist, and I’m here to set the record straight about Variants and Reinfections.
Dr. Kamil works at Louisiana State University Health Shreveport as an associate professor of microbiology and immunology and as a virologist.
The rush of Omicron variants has felt like one long wave. A lot of questions have come up because of all the chaos. Are we seeing the rise of completely new types of coronavirus that can’t be stopped by vaccines or previous infections? Is it inevitable that most of us will get long Covid if we keep getting infected?
The short answer is “no.”
As a virologist, I think it’s important for people to know that Covid-19 is still a big worry. But that doesn’t mean it’s okay to get the current situation wrong.
First, let’s talk about what’s true. BA.5 is everywhere, and it is one of the newest types of Omicron. It is undeniable that it is more likely to spread than previous Omicron lineages. This is likely because it is better at avoiding the antibodies we already have.
BA.5 and its close relative BA.4 have a key mutation that lets them get by a key class of antibodies called “broadly neutralizing antibodies.” These antibodies did a great job of keeping people from getting sick from a wide range of earlier versions.
Some things have changed about that.
In the past few weeks, I’ve seen many people who had been vaccinated get the coronavirus for the first time. One of my coworkers got sick in May and again in June after being infected. This is the kind of case that worries me the most.
Luckily, it is not common to get sick again a few weeks after getting better. Scientists have found that people who have had Covid-19 before are less likely to get infected with the current variant than people who have never had Covid-19. The same is true for Omicron. Early research from Qatar that hasn’t been reviewed by other scientists yet showed that people who had a BA.1 infection in, say, January were much less likely to get a BA.4 or BA.5 infection a few months later. Even though more research is needed, these results fit with how immunity at the level of a population helps explain the rise, fall, and size of epidemic waves.
Antibodies are still one of the best ways to fight this coronavirus. They do many things to keep us safe, and they also mark the virus so that other parts of the immune system can kill it. Even though some studies have found that Omicron variants may cause weaker antibody responses than earlier variants, this is probably because Omicron causes less severe disease thanks to vaccines and previous infections.
Our immune system works a lot like a smart but thrifty investor. It adjusts its responses based on the size and number of danger signals it senses during an infection. In general, the stronger the antibody response, the worse the symptoms and illness from infections like Covid or the flu. When antibodies are good enough to keep disease to a minimum (because fewer virus particles are able to replicate in the body), we tend to see a lot fewer antibodies than when someone gets the coronavirus and ends up in the hospital. Vaccines are a great way to get around this problem. They tell our immune systems to make antibodies and other defenses even when there is no disease.
Immunologically, the population is a mix of different kinds of people right now. Even if a person has been vaccinated, they may still get Omicron infections if they were infected with an older type. People who have never had Covid may get it now. Some people who got sick from an earlier version of Omicron in December, January, or even more recently are now getting sick from BA.5.
Nuance is not a friend of the current situation, in which some people are now more likely to get sick while others are still safe. It’s hard to make broad statements and bold predictions about how well an individual or a group will fight off an infection now or in the future. But even though Omicron is good at getting around antibodies, it’s clear that previous immunity, whether from vaccines or previous infections, protects against bad outcomes like hospitalization and death. There hasn’t been a change that makes vaccines less useful.
A recent study that was not peer-reviewed said that reinfections are just as dangerous as the first infection. However, scientists and medical experts do not agree on this at all. (Really, the study only showed that getting sick again is worse than not getting sick again.) Other scientists worry about the long-term effects of getting infected more than once. But there is no question that being immune to something in the past makes most infections less severe. Catching the coronavirus more than once or after getting vaccinated does not necessarily put someone at risk for the most serious and chronically debilitating forms of long Covid, but more research is needed to figure out what might put someone at risk for that.
The Food and Drug Administration should move quickly to approve new booster shots that target Omicron variants. Based on what we know now, updated shots, even if they were based on earlier Omicron lineages, would be better at preventing infections than the current vaccine boosters, which are based on the first 2019 coronavirus spike.
In the meantime, if you are eligible, it’s smart to get a boost with the shots that are already available, which are still great at keeping people from getting sick or dying. (This is very important for people over 65.) If you don’t want to weaken your immunity, you should still wear a mask when socializing indoors and avoid eating inside when the number of cases is high. The good news is that monoclonal antibody cocktails are still effective against BA.5. One of these products, Evusheld, is used to keep patients safe, while others are used to treat serious infections. People who test positive and are eligible for Paxlovid may also find it helpful. It can be taken at home.
Most immunologists I know are cautiously hopeful about our future. We don’t know what this virus will do next, and we should never ignore people who are at a high risk or who have a long Covid. Still, most of us can trust our immune systems, especially when we get vaccinated and get booster shots. There may not be many examples of something like the Covid-19 pandemic in recorded history. But our immune systems have been through this before.