Covid immunity in 2024?

March 4, 2024 10:59 AM

What do we know about Covid immunity nowadays? I just had Covid two weeks ago. Am I safe for any appreciable period?

I am fully vaxxed + boosted, and hey I also still mask. Which means it came as a big surprise when I got Covid about three weeks ago.

(As an aside, I would have bet you a million bucks I only had a cold, but after testing negative once, I then turned positive about 48 hours after symptoms started, and stayed positive for 10 days. I never had a fever.)

So how much immunity do we think I have, going forward?

posted by BlahLaLa to Health & Fitness (14 answers total)

I got the new vaccine mid September. Caught COVID 2 weeks later (because cruise). Caught COVID again 4 months later. The second time around, I would never have known it was COVID (no fever, barely any symptoms), but I took a test and it was positive. So, for me, I guess it provided a much more mild case, but certainly didn't prevent me from catching it again even just a few months later.
posted by skunk pig at 11:12 AM on March 4

I wouldn’t factor any possibility of immunity into my risk assessment. I’d carry on with whatever precautions I normally carry on with.
posted by Gymnopedist at 11:24 AM on March 4 [13 favorites]

I take a different approach to risk management than Gymnopedist. My level of precaution varies based on a few factors:

General environmental risk (is there a lot of COVID now or little? I base this on wastewater figures, test positivity rates, etc.

COVID impact: How much would it suck to get COVID right now? If I have a trip, a big event, or an important obligation coming up in the next couple weeks, I'll be more cautious. If it's a time where isolating for 2 weeks is merely annoying, I'll be more willing to go out to eat with friends, or whatever.

Personal immunity levels. Have I recently had a booster or infection?

In terms of the last point, based on blog posts I read from experts a couple years ago about stuff like "when should I get my vaccine after an infection", my general policy is I consider my risk factor lower for 0-3 months after a vaccine or infection, and higher 9+ months after my latest vaccine/infection.

Of course there's no guarantees anywhere, and even taking extreme precautions under good risk conditions there's some chance of catching COVID.

posted by aubilenon at 11:50 AM on March 4 [3 favorites]

I've been working on the idea that I am covered for about three months post-Covid (not vax or booster, but Covid itself), also because I held off on getting my booster til after that period.
posted by bluedaisy at 11:55 AM on March 4 [1 favorite]

(Not licking-doorknobs covered, but generally probably a bit more protected.)
posted by bluedaisy at 11:55 AM on March 4 [1 favorite]

One thing to remember is that "immunity" in medical jargon is basically what you'd call "resistance". It's not like diplomatic immunity where laws don't apply, or like a fire elemental being immune to fire damage. It's a tendency, not a rule.

So no, you're not 100% safe from Covid, for any period. However, your resistance is elevated relative to your uninfected and unvaccinated state. It's also probably elevated relative to the week before your infection.

We can measure antibodies, and e.g. this 2023 research concludes expected antibody response after COVID-19 infection robustly increases for 100 days postinfection, and predicts individuals may remain antibody positive from natural infection beyond 500 days... The amount of anti-bodies varies wildly between individuals. Some get a huge boost, some get very little.

So for 100 days or so, you probably have more resistance than you did before. Hard to say how much more, for you specifically. This resistance may lower your chances of infection given a certain exposure level, and it may lower the severity of symptoms if you get infected. Usually protection against high severity lasts longer than protection against reinfection. But you can still get sick with Covid next month or next week.

There are some attempts to quantify the degree of protection granted by infection. These reinfection results necessarily are not well controlled, and there are lots of variables in terms of behaviors, exposure levels, not to mention strains involved etc. This review article discusses several research results, listing some studies showing around 80% reduction in reinfection, but the time frames and methods are variable. The CDC is now saying 98% of the USA has some immunity due to vaccination and/or infection. Clearly reinfection is very common in the aggregate, and the rapid evolution of this pathogen would seem to preclude any truly long-term immunity as we see with some other diseases like Chicken Pox.

So yeah, I personally wouldn't do much different. Some people feel a little more confident not masking in situations where they would have before, and some of those people get reinfected sooner than they would have if they kept up their previous defenses. On the other hand, among people who were doing no risk reduction prior to infection, infection rates will be lower on average in the months after infection. Personal risk tolerance varies wildly, ymmv etc.
posted by SaltySalticid at 11:56 AM on March 4 [7 favorites]

Sorry for a lack of sources, but to my recollection (from sources lost), no, not at all. I had covid twice back-to-back in Dec and Jan with a nice break for Christmas.
posted by lokta at 11:57 AM on March 4 [2 favorites]

My current understanding is you probably have some protection for a few months from the strain you got - but there are enough strains circulating most of the time that that doesn’t mean as much as you might want it to.
posted by Stacey at 12:29 PM on March 4 [5 favorites]

Depends what you mean by "safe". If you mean "zero percent chance of getting covid", no. If you mean "substantially less chance of getting very sick from covid", then yeah.

https://www.cnn.com/2023/02/16/health/covid-19-infection-immunity/index.html
"For at least 10 months after a Covid-19 infection, your immune system can provide good protection against symptomatic illness the next time around"

https://theconversation.com/how-long-does-immunity-last-after-a-covid-infection-221398
"A prior infection showed a high level of protection against severe disease (above 88%) up to 40 weeks regardless of the variant a person was reinfected with."

I'm not sure what precautions you are taking. Personally, as a healthy person who is vaccinated and boostered, and then got covid, I would personally take no more cautions than I did in 2019. YMMV
posted by ManInSuit at 12:30 PM on March 4 [1 favorite]

I think each person is different, and we all have to know our own bodies ourselves. I had the original two-step shots and the first booster after that. Then I got Covid in either late 2021 or early 2022. Spent 3 days in misery and have not looked back. No more boosters.. No masks. The only precautions I take is to wash my hands often, but especially after a trip to the grocery whereby I have touched/pushed a cart/wagon. At first I thought it was because of natural immunity from the time I had it, but now after 18+ months, I just think I am not as susceptible to it as some others might be. I am also not afraid to get it. While I am in several "high risk" categories including age and weight, if I get Covid, I wiill deal with it as it comes. It seems to me to be an illness that has different degrees of severity, and that each person reacts to differently.

So, I think you should keep doing what has worked for you. If getting boosters and masks has mitigated your risk, go for it.

Parenthetically, I have never gotten the flu shot (initially for good medical reasons) and I have never gotten the flu. Anecdotally, most people I know who have gotten the recent boosters have gotten covid a few weeks later albeit a mild case.
posted by JohnnyGunn at 12:40 PM on March 4

From a slightly different perspective, it might also be worth thinking about your actions in the several months after getting COVID as part of the risk profile for long COVID. Two friends of mine, both healthy, active people in their thirties, have in the past two years wound up with long COVID so debilitating that they have had to quit their jobs and be taken care of by family. I don’t have any citations handy, but I know there are guides out there from long COVID communities on strategies for taking it easy and being intentional in moving your life speed back up to normal. (One of those friends shared a guide including advice about using OTC meds/vitamins/supplements to reduce the risk of ending up with long COVID, but I have no understanding of whether that advice is sound, so I’m not sharing it here.)
posted by rrrrrrrrrt at 2:27 PM on March 4 [12 favorites]

Recent research shows that JN.1 [the prevailing variant currently, a descendant of omicron] is very efficient at immune evasion. There's a helpful bar chart showing how JN.1 has come to dominate cases.

Also:

The JN.1 variant, which is a subvariant of omicron, accounted for 83%-88% of all currently circulating variants of SARS-CoV-2 as of Jan. 19, according to the CDC. The subvariant is known among virologists as a “hypermutated variant,” Sette says.

“That is potentially concerning in the sense that it’s associated with potential for escaping the neutralizing antibody response,” notes Sette.

This could explain an increase in people getting symptomatic disease, even after having been vaccinated or previously infected. Still, evidence suggests that this variant does not cause more severe disease than other variants. And T-cells, the body’s second line of defense against foreign pathogens on a cellular level, continue to respond well to infections with JN.1...

posted by spamandkimchi at 2:39 PM on March 4 [3 favorites]

Also looking up more info on the protection afforded by T-cells (which has been more robust in responding to all the escape-artist variants), some types help clear infection but don't necessarily prevent infection:

vaccines expose patients to a piece of an invading microbe to generate responses that include B and T cell activation, so that the system is ready for the invader should it be encountered again... B cells produce antibody proteins that neutralize and label infected cells for removal from the body.

In the rush to develop vaccines against SARS-CoV-2, and with the rapid testing of thousands of patients this required, clinical trials relied mostly on antibody levels... T cells were suspected to be at least as important to this protection, but standard methods for tracking them were too slow, and so careful analyses of CD8+ T cell responses were sidelined....

...When study authors checked for these profiles in hospitalized COVID-19 patients, those with the most “properly programmed” T cells were the most likely to successfully recover from their infection.

posted by spamandkimchi at 2:47 PM on March 4 [1 favorite]

Thanks for asking about immunity BlahLaLa, I got the updated vaccine in October but have a multi-city project trip coming up so it's a good reminder to stay careful. The last time I traveled for work I went down HARD with my first (that I noticed) bout of Covid. The last link I swear -- TODAY show has a (surprisingly) thorough explanation of JN.1 dated Dec 2023:

Nearly all COVID-19 cases in the United States right now are being caused by one, highly contagious variant called JN.1. The fast-spreading omicron subvariant currently accounts for over 93% of cases nationwide and the majority of infections globally.

....In early November, JN.1 accounted for fewer than 1% of COVID-19 cases in the U.S. Several weeks later, it was driving over 20% of cases, Dr. Michael Phillips, chief epidemiologist at NYU Langone Health, tells TODAY.com. Now, only two months later, it's causing nearly all cases nationwide.

posted by spamandkimchi at 2:58 PM on March 4 [1 favorite]