Here’s a good YLE post on it. It does seem like a strong possibility. I think the more important connection is that several European countries are seeing cases go up again due to BA.2 and BA.2 has a high reinfection rate. The USA has tended to follow the trends in Europe but delayed about 3 to 4 weeks, so I’m certainly keeping an eye on things. I was finally going to have a housewarming party at the end of April. Damn it.
according to this, the reinfection rate is fairly low. it also says many of the reinfection happened among young, unvaccinated people and the disease was minor when it happened.
the YLE article also says that 45% of Americans caught omicron already (or at least that’s my impression of what they meant). so hopefully crossover immunity will help reduce rates.
What about boosters? I got boosted in early December, these articles imply the BA.2 variant will hit around April or may. that could be six months since a booster shot, will the booster still be effective at that point?
Covid is still far too new for any good predictions of how long the vaccine will be effective. However, it is quite clear that the vaccine will still be providing some protection. We just don’t know how much.
That article is three weeks old (covid time moves fast!), but I’ll retract that bit and clarify my thinking. That reinfections are happening at all so quickly after a previous infection is concerning to me especially if immunity wanes quickly. It’s rare now, but will be less rare for those that caught early omicron infections and will be even less rare in a month and so on. That combined with the fact that every state has plans to end pretty much all restrictions soon and so the opportunities for transmission go way up and even rare events can happen often.
Then there’s 55% of the population that didn’t get omicron, fewer people getting boosters, lots of people still unvaccinated… It seems to me that we are setting ourselves up for another wave like we have stupidly done before. Maybe it will be blunted by the last omicron wave, but it seems like rosy assessments have a way of smacking us in the face shortly afterward.
The YLE article @duality72 posted is saying we’ll be hit in April/May and covid in the sewage is just starting to tick up.
Two bits of potential good news:
BA.2 was 8% in the US on March 2 and only about 10% right now. That means it’s having a hard time taking hold. Omicron shot up much faster. I bet that’s because so many in the US were infected.
I wouldn’t be surprised if most our unvaccinated have been infected by both Omicron and an earlier variant. Seroprevalence estimates for infection only were 35-50% in low vaccination states BEFORE Omicron. These estimates shot up to over 50% by Jan 22. I expect those to now be closer to 60%. Plus, lots of the unboosted got their booster by getting Omicron.
The best data to look at now is ICU patients. I’ve been monitoring Denmark and UK in ourworldindata.org during their Omicron and BA.2 surges. Massive case numbers, but ICU patients very low relative to the US. Now that most our unvaccinated or partially-vaccinated have been infected by something, I hope we’ll look the same.
Of course vaccines and previous infections will help stop it from exploding. If they didn’t, it would upend everything we know about the immune system. The question isn’t whether it’ll help; it’s how much it will help.
This kind of data from a more recent study of Denmark is what I was thinking of in that Omicron seems to provide a much lower level of protection against reinfection and that protection wanes quicker. It’s from a preprint study, though, so caveats apply.
Oh, and I would add that even if the infections are generally milder, we saw with Omicron that if there are enough infections out there, you still end up overwhelming the medical system and incurring way more suffering and loss of life than necessary. I wish we would not tempt fate like that again, but apparently most government leaders, many corporations, and much of the public feel otherwise.
“…everything we know about the immune system…” is (to non-experts) a surprisingly incomplete subject area of medical knowledge. In fact, next to cognitive neuroscience it is probably the most active area of fundamental research in medical science. The vaccines, designed to prime the immune system to resist the original ‘wild type’ SARC-CoV-2 pathogen, and previous infections may be of some benefit in providing a protective immune response but it is clear that breakthrough infections are common even back to the ‘Delta’ variant, and that the primary advantage of prior immunization (whether through vaccination or prior exposure) is in mitigating the severity of the COVID-19 syndrome. How protective it is against Post-Acute Sequelae of SARS-CoV-2 (a.k.a. “long Covid”) is unknown but the experience of Post-Polio Syndrome is a cautionary tale against assuming that long-term consequences are negligible.
That graph must mean reinfection by the indicated variant after prior infection by a previous variant, not reinfection with BA.2 after having BA.1. So infection by some prior variant protects well against reinfection by alpha or delta. That protection is significantly diminished when Omicron (BA.1) came along.
Eric Topol posted a link to the wrong paper. The only Danish study I could find doesn’t have that graph and data emphasize that reinfection with BA.1 or BA.2 after a BA.1 infection is very rare. Only 47 reinfections with BA.2 after a BA.1 infection out of 1.8 million infections investigated from Nov 2021 to Feb 11. That’s tiny.
Yeah, looks like that is the case. I tried to locate the original paper, too, but came up empty. Sorry for not catching that, so withdrawn. This paper is a better source for what I was thinking anyway, though still a preprint. Essentially the milder infections of omicron also seem to induce lower immunity against future variants. In this case, though, with BA.2 being closely related to BA.1, that doesn’t apply as much, so I guess I’ll lower the worry on that aspect.
That’s not exactly what the study says, though. The 1.8 million total infections during the studied period says nothing about how many of those people were specifically re-exposed to BA.2 after an initial infection to BA.1. Essentially, we don’t know what the denominator is here, but it’s almost certainly much, much less than 1.8 million.
The study did find “1,739 cases that fulfilled the criteria of two positive samples with more than 20 and less than 60 days apart.” Of those 1,739 cases, the researchers randomly selected 263 samples that could be genetically sequenced and, of those, 187 (71%) were BA.2 reinfections and 47 (18%) were specifically Omicron BA.1-BA.2 reinfections. So that’s not 47 out of 1.8 million infections investigated, but 47 out of the 263 reinfection samples successfully sequenced.
The significance is that this is a study in Denmark in which BA.1 was dominant in Dec-Jan followed by BA.2 dominance in Jan-Feb 11. The vast majority of the 1.8 million cases in that timeframe were BA.1 and BA.2. According to this paper, 80% of cases were BA.2 by Jan 18. In fact, the vast majority of cumulative Danish cases are now BA.2.
Look at cumulative Danish cases in ourworldindata and I think you’ll see how BA.1 swamps the number of Delta cases by mid December. By mid Jan, BA.2 swamps BA.1. The combined Omicron waves account for nearly 90% of Danish cases. Over 50% of Danes have now officially been infected.
So, 187 cases out of a little less than 1.8 million (lets say even 10X less) are a BA.2 reinfection from a prior infection. 47 of those are specifically BA.2 following a BA.1 infection. These are tiny numbers. The majority of those 1,739 are reinfection by BA.1 with a prior infection of something else. Notice, these are still small numbers because, prior to Omicron, Denmark had a very low infection rate.
Their death rate looks bad, but they count anyone who has died of anything within 30 days of a positive test. I’ve been looking at their number of ICU patients which have been low the whole time (relative to the US).
This is still way off. It’s 187 cases out of → 263 cases successfully sequenced out of → 1056 samples selected for additional sequencing because there was a good sample pair out of → some unknown portion of people that were infected and then exposed again out of → the 10% or so of infections sequenced at all (2021-W49 through 2022-W04) out of → 1.8 million. I’d still call that rare but not tiny.
I’m also considering that this was during a time when restrictions were high and thus opportunities for re-exposure occurred less often. With restrictions going away pretty much everywhere in the states, there’s going to be a lot more chances for re-exposure such that even rare events can happen a lot more often. There was a time when omicron after delta reinfections were rare, then delta restrictions started to go away and omicron took off.
So it’s not like I’m sure this will be a significant factor in the next (possible) wave, but I don’t think it should be entirely dismissed yet. The bigger problem will be the 55% of Americans who didn’t get omicron going back to “normal”.
I dunno, I’ve gotten kinda cynical about restrictions of any sort lately. I’ve become less and less convinced that there’s a sufficiently high number of people who will obey them and power structures that will enforce them (not necessarily limited to the United States) to really make it worthwhile.
As for the OP, it kind of depends on what you consider a “wave.” Is it any sort of increase in cases, no matter what the amount? In hospitalizations or deaths? Is there a threshold where we can be confident that the wave, however you define it, is directly caused by lifting restrictions (kind of like how scientists estimate that there’s an 80% chance that any unusual weather event is caused by climate change)?
Something that just occurred to me: I could see a scenario where the blue states get a larger increase than red states, for reasons I’ve already described above. I bet the right wing machine would love to see that…
Okay, I think I got it. In the materials and methods, it says this:
In order to increase the number of paired genome data for patients infected with Omicron lineages, samples were selected for WGS from individuals with two SARS-CoV-2-positive samples 20 to 60 days apart. From a total of 1,739 individuals that fulfilled the criteria, a subset of 984 samples from individuals (n=492) without prior WGS results were randomly selected for sequencing. Moreover, 74 individuals had at least one Omicron sample already confirmed by WGS and the remaining samples were selected for WGS. In total, 1,056 samples were included (Figure 1).
Those 1739 are the total number of people reinfected (mostly omicron - omicron) from the total 1.8 million infections. That’s less that 0.1% reinfection rate within that period.
1056 of those 1739 were selected for sequencing or were already sequenced. They couldn’t get sequencing for all of the 1056 samples (almost half failed).
Even though they selected a timeframe to get as much Omicron as possible (probably at least 90% of the samples), the majority of reinfections (53%) came from delta to BA.2. Next, 19% were reinfection with the same variant: delta to delta, BA.1 to BA.1, or BA.2 to BA.2. Finally, 18% of them were BA.1 to BA.2. Since that BA.2 wave was only half-way through at the time, those numbers may double at least.
If those percentages represent what is in the 1739 reinfected, you are talking about a certain percentage of the 0.1% reinfected. The good news is that the majority of those reinfections are delta to BA.2. Since the first and second infections were in a narrow range, less BA.1 to BA.2 suggests a protective effect rather than waning immunity.