Just thought I’d add this to the discussion of vaccine versus immunity from COVID. It’s from an email I got today from a hospital where I’ve had surgery:
Should I get a COVID-19 vaccine if I’ve already had COVID-19?
If you’ve had COVID-19 and recovered, you may wonder if you still need to get vaccinated against the virus.
While a previous infection provides some natural protection or immunity, it’s unclear how long this protection lasts. That’s why the Centers for Disease Control and Prevention recommends the vaccine even for people who have already had the virus. Recent evidence shows that being fully vaccinated creates more effective and longer-lasting immunity than natural immunity from infection. One study showed that among people who already had COVID-19, unvaccinated people are more than twice as likely as fully vaccinated people to get reinfected with COVID-19.
(I bolded the most relevant bits–except for the question/heading.)
I wish they’d included cites. Though the hospital has an excellent reputation, it’d be nice to know which studies and when they were conducted.
The rest of the email covers the safety of the vaccine and the guidelines for someone who has COVID now or recently had COVID.
As you mentioned previously, that Kentucky study only looked at people who were previously infected or previously infected + vaccine. It’s a nice study that shows that vaccination following infection still provides additional protection.
I think this study is much more relevant.
I’ll note that this contradicts a study out of Israel showing that previous infection is more protective than the mRNA vaccine. The discrepancies may be due to waning immunity since Israelis were fully vaccinated earlier than Americans. If true, maybe it suggests that vaccination is better protection within a six month period, but diminishes faster with time. It may also suggest behavioral differences in the vaccinated vs. unvaccinated in the two countries.
Yeah, that study has a weird design, which has me questioning whether it means what they say, particularly because of things like behavioral differences and selection bias. It may be accurate, but it’s hard for me to see how the design is accurately measuring what they want it to measure.
They looked at people who were already hospitalized, who had covid-like symptoms, tested them, and determined that the people who had been vaccinated were more likely to be sick with a non-covid illness than unvaccinated people who had already recently had covid.
The Israeli study looked retrospectively at health records over a three month period. That design could also have been flawed, because people who had already had covid might not have chosen to be tested if they thought they couldn’t get Covid again, so both studies have potential issues. There needs to be observational studies with ongoing regular testing and behavioral guidelines.
Wasn’t the Israeli study comparing infection from COVID and vaccination by Pfizer only? And Pfizer, as we all know, does show waning immunity over time. Also, the study naturally didn’t include Israelis who’d had boosters.
I’d like to see a study that included subjects who were fully vaccinated with Moderna. I’d also like to see one comparing those vaccinated who’d received boosters vs. those who’d had COVID and were unvaxxed. If receiving boosters makes one less likely to get reinfected than two doses of Pfizer alone, that’s the comparison that should be made, isn’t it?
All the vaccines show waning immunity over time. I don’t have a source handy, but the CDC (NIH?) published a nice graphic.
According to a friend who is neck deep into covid research, antibody levels drop off by about a factor of 2 each month after your initial vaccination peak. A factor of two is a fairly small difference in effectiveness, so the decay in immunity is slow. And the primary reason that Moderna holds up better is because people who had it started with higher antibody levels. (Higher than are useful, which is why recently vaccinated people with Pfizer did about the same as those with Moderna. But then dropping at about the same rate as people who had Pfizer.)
He also says that preliminary indications are that you lose antibodies slower after a booster than after the initial series, maybe a factor of two every 6-7 weeks. But of course, we won’t really know how well the boosters hold up until more time has passed.
Let’s suppose just for now that the boosters also lose effectiveness over time. If the science indicates, for instance, that a booster will be needed every six months, it’d still make more sense to compare patients who’ve recovered from COVID to those who stay current with booster shots, both in terms of immunity and ability to spread infection.
And, of course, vaccinated people who get breakthrough COVID are only half as likely to get Long COVID, are more likely to be asymptomatic, much less likely to get hospitalized or die, and, I presume, end up with a higher level of immunity than people who get COVID and don’t get vaxxed afterward.
I think this has been established.* It was discussed in a Science article I posted a day or two ago.
People who’ve both been vaccinated and had covid have more resistance to infection than people who’ve only had one or the other. Further, there’s evidence of a greater resistance to variants than either of the other groups as well. The exposure to the entire virus for some time probably makes people who’ve had covid better able to “recognize” a variant, and being vaccinated helps to provide a more robust response, is the hypothesis, I believe.
*Oh, yeah, it was also exactly what the CDC study in the link I posted today was about. That study was about unvaccinated people who’d had covid vs vaccinated people who’d had covid, comparing rates of subsequent reinfection.
One thing I’ve been wondering about is if it’s beneficial to have regular, low-level exposure to the virus to keep your immune system up. If every now and then a few virus particles make it into your system, would that trigger your immune system to create more antibodies? Like in a crowded city, perhaps it would be beneficial for vaccinated people to walk on the sidewalk without a mask where viral load would be low. Indoor environments can have high viral loads that could still be dangerous and mask usage would be best, but outside I would think the density of viral particles would be low enough that your immune system would be able to handle it. I’m wondering if vaccinated people who mask up everywhere may be living in an environment that’s too sterile and it allows their immune system to slack off.
I’m a little confused about all the focus on antibodies. I thought it was expected that antibodies would tail off, and other immune system cells take over – the memory cells. Then, with subsequent exposure, the antibodies ramp back up after the memory cell recognize the virus.
So what we need, I thought, was studies of actual infection rates, and severity of infection, to compare groups and determine protection.
I understand that antibodies are measurable, but the reporting on these studies even notes that no one knows what level of antibodies is protective.
In fact, there was a study in which they sequenced the virus from the blood of someone who had covid for over a month. Turns out selective pressure in the person’s body resulted in mutations of all the known variants at the time. That means people who have had covid may have antibodies against viruses with various mutations in their spike proteins. In addition, a person who had covid will have anti-N antibodies; the N protein does not mutate as much as the spike protein.
“What happened at the Travis Scott concert? … As others have said, this is a test run on the vaxxed.” — Facebook post
Investigators are still looking into what caused the crowd surge at Houston’s Astroworld music festival that killed eight people and injured dozens more during a performance by rapper Travis Scott.
Some people on social media claim to have an explanation: the COVID-19 vaccines. The post goes on to say that a material called graphene oxide can “destroy consciousness” and control people through magnetic frequencies, which includes music.
…
I’m not even going to bother quoting the fact-checking rebuttal from the article.
The real problem, obviously, is that people refused to wear the anti-graphene oxide tinfoil hats that were issued at the entrance. I read on a special insider news site that thousands of the special bad-stuff filtering items of headgear were found trampled on the ground, and secret The Deep State police quietly swept them up and stuffed them into garbage bags to be hauled away before the mainstream media could get a look at them. Or some bullshit like that.
I’ve been tested for both rubeola and rubella antibodies.
The first was required to get a marriage license. (That or a new vaccine, or a stern lecture from a doctor about why i should get the vaccine.) The second was when measles was in the news. I’d had a bad reaction to the measles vaccine, so when issues were found with some of the batches my age-cohort had, and we were all supposed to get a booster, my mother and my doctor agreed i shouldn’t do that. So i decided it would be safer to check and see if i had antibodies, and only get a new vaccine if i didn’t. My current doctor agreed, and i got tested. I “passed” both those tests.
For most bugs, we have a pretty good idea of how often we need boosters, and nobody does routine testing of antibodies. But it seems to be a thing that can be done, when there’s uncertainty. And we don’t know, yet, with covid.
The Israeli data that prompted booster shots was data on infections, not antibody data. But there’s since been work measuring antibody levels, too. And i expect doctors will eventually know what measurements correspond to acceptable levels of immunity.
My daughter the nurse and her husband the doctor have been leading the fight to make vaccination
a requirement for employment at their hospital. Latest numbers show only 70% of employees (including custodial, administrators, etc) are vaccinated.
Because of upcoming mandates, vaccination by January is now a requirement! The hospital is facing crazy times ahead, though. My daughter is in obstetrics, which is not a money maker for the hospital, which may stop delivering babies.
Luckily, a new hospital is opening ~30 minutes from their home, and she will be able to work there in obstetrics if her current department is axed (her current hospital would expect her to accept being moved to another department).
On the plus side, my son-in-law is signed up for a continuing education meeting in Hawaii in March, so they are excited about that.
Still very useful info!
