I have a friend who keeps insisting that having previously had Covid is as good(better I think he said) protection than being fully vaccinated.
Is he right? I often find data of vaccinated vs. unvaccinated, but I never see “previously contracted Covid” as a category.
Well, the CDC just came out and said that vaccination on top of natural immunity offers more protection than natural immunity alone.
And This report seems to say that vaccination is better against variants.
But I haven’t seen anything directly comparing natural vs vaccine.
There are some studies coming in that show folks with vaccine immunity who have breakthrough infections have fewer severe cases than breakthrough infections in folks with previous infection immunity. That’s why current advice is for covid survivors to get the vaccine too.
Moving to the Quarantine Zone.
Here’s a study from Israel (full pdf) looking at reinfections across three groups:
The study looks at the time period where the Delta variant was dominant in Israel.
This is the largest real-world observational study comparing natural immunity, gained
through previous SARS-CoV-2 infection, to vaccine-induced immunity, afforded by
the BNT162b2 mRNA vaccine.
Results
SARS-CoV-2-naïve vaccinees had a 13.06-fold (95% CI, 8.08 to 21.11) increased risk
for breakthrough infection with the Delta variant compared to those previously
infected, when the first event (infection or vaccination) occurred during January and
February of 2021. The increased risk was significant (P<0.001) for symptomatic
disease as well. When allowing the infection to occur at any time before vaccination
(from March 2020 to February 2021), evidence of waning natural immunity was
demonstrated, though SARS-CoV-2 naïve vaccinees had a 5.96-fold (95% CI, 4.85 to 7.33) increased risk for breakthrough infection and a 7.13-fold (95% CI, 5.51 to 9.21)
increased risk for symptomatic disease. SARS-CoV-2-naïve vaccinees were also at a
greater risk for COVID-19-related-hospitalizations compared to those that were
previously infected.
Some of the raw numbers:
46,035 persons in each of the groups (previously infected vs.
vaccinated
When comparing the vaccinated individuals to those previously infected at any time
(including during 2020), we found that throughout the follow-up period, 748 cases of
SARS-CoV-2 infection were recorded, 640 of which were in the vaccinated group
(breakthrough infections) and 108 in the previously infected group (reinfections)
552 symptomatic cases of SARS-CoV-2 were recorded, 484 in the vaccinated group and 68 in the previously infected group
COVID-19 related hospitalizations occurred in 21 and 4 of the breakthrough infection and reinfection groups, respectively
No COVID-19-related deaths were recorded
Conclusions
This study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant.
My thoughts: This is absolutely fantastic news. The vaccines are outstanding, and strong natural immunity takes nothing away from that. We should all be hoping for strong and lasting natural immunity, especially given the number of natural infections out there.
An article in Science about the study:
This study contradicts previous studies and I’m not sure why. Is it something weird with Israel again? I did notice that they focused on people vaccinated from Jan - Feb which probably toward co-morbidities. They did normalize for age though.
Do you have a link to previous studies showing the opposite? I think this is the first study of this type I’ve come across.
In the Israeli study it looks like they also adjusted for comorbidities:
In all three models, we estimated natural immunity vs. vaccine-induced immunity for
each SARS-CoV-2-related outcome, by applying logistic regression to calculate the
odds ratio (OR) between the two groups in each model, with associated 95%
confidence intervals (CIs). Results were then adjusted for underlying comorbidities,
including obesity, cardiovascular diseases, diabetes, hypertension, chronic kidney
disease, cancer and immunosuppression conditions.
Not right now. The studies were pre-Delta and people’s vaccinations were more fresh.
I’m going to guess that this friend is using this as an argument to avoid vaccination.
While it’s certainly possible that the new study out of Israel is accurate under their specific testing conditions, and even if your friend ignores the studies referenced by @Qadgop_the_Mercotan, I’m unaware of any study that says that having COVID previously is as good as both having it previously AND being fully vaccinated. My response to said friend would be:
And? Get vaccinated and be even safer.
Short answer: no one knows for sure in a specific person. It is certainly possible. The advice for people who have had Covid to get vaccinated remains good. Remember up to fifty percent of Covid patients may have “long Covid” although I suspect some of these residual symptoms reflect these unusual times and might be found in those without Covid too at a lower rate.
He’s not the worst out there. And I don’t think he is anti-vaccine. I think he is one of those people who get really caught up about vaccine mandates and so forth. He thinks, and now I kind of see the point, that perhaps if you have proof you had Covid, that should count as enough proof to equal vaccination.
He’s definitely a big believe in rights, at least when they suit him.
He isn’t the anti-science guy that many out there are, though.
If you had a time machine, then this might be an argument for going back in time and deliberately being infected with original-strain Covid, so as to maximize protection against the more dangerous delta strain.
But it would be a terrible argument for deliberately getting infected now, because that would mean that you’re trying to avoid delta infection by… getting a delta infection.
Nor is it an argument for not getting a vaccine because you’ve already had the disease, because prior infection and vaccination combined provide an even greater protection.
What it’s the best argument for, is figuring out the mechanism by which prior infection provides stronger protection, and using that information to develop even better vaccines.
The problem with that argument is that from what we have seen, while many get better protection (from the original strain, not necessarily delta) through infection, others do not. It’s highly variable protection from none at all to better than the vaccines.
The vaccines offer much better uniformity in protection at a high level.
Best of all appears to require a bit of luck, i.e. acquiring a high natural immunity from infection and reinforcing it through vaccines. That first part isn’t guaranteed and the only way to test it is by getting re-infected, which is all kinds of dumb.
Yes natural immunity provides better protection.
The process of betting it also provides a much higher risk of you know, dying, being very seriously sick, etc,etc.
Get the damn shot.
Yes, get the damn shot, but no, natural immunity does not provide better protection:
I> n today’s MMWR, a study of COVID-19 infections in Kentucky among people who were previously infected with SAR-CoV-2 shows that unvaccinated individuals are more than twice as likely to be reinfected with COVID-19 than those who were fully vaccinated after initially contracting the virus. These data further indicate that COVID-19 vaccines offer better protection than natural immunity alone and that vaccines, even after prior infection, help prevent reinfections.
“If you have had COVID-19 before, please still get vaccinated,” said CDC Director Dr. Rochelle Walensky. “This study shows you are twice as likely to get infected again if you are unvaccinated. Getting the vaccine is the best way to protect yourself and others around you, especially as the more contagious Delta variant spreads around the country.”
Thus sayeth the CDC
This is from the same media statement you cited on 8/23. I think the statement that “COVID-19 vaccines offer better protection than natural immunity alone” is about as definitive as it gets.
The CDC results are similar to the Israeli results. They are comparing people who have had the virus (natural immunity) with those who have had the virus and are then vaccinated but are not including those who are vaccinated without having had Covid.
The way I explain it to my patients who claim they have had the virus and now have immunity is as follows:
Nothing is perfect in preventing you from being reinfected if you have the original Covid. The worst is no vaccine and no infection (hold hand at hip level). The next best is full vaccination (hold hand at waist level). Even better than that is having had the disease (hold hand at mid-chest level). If you’ve had the virus and gotten over it you are lucky because you have better immunity than people who just got the vaccine. Even better, though is getting over the virus and then getting the vaccine (hold hand at head level). The protection from both the vaccine and getting the disease seems to decrease over time but if you’ve had Covid and then get the vaccine, it helps to rev up your immune system even more to prevent another infection.
Does the intensity of the original infection correlate with the level of protection and possibly duration?
That quote doesn’t say what you’re saying it says. It’s not comparing people who just have the vaccine to people who just had prior infections. It’s comparing people who had the vaccine and prior infection to people who just had prior infection without the vaccine. Everyone agrees that having both is the strongest protection of all.
Update from the CDC: seems that infection or vaccination give similar levels of protection, each begining to wane at 6 months. Infection plus vaccination being better than either alone, and so they continue their recommendation for everyone to get vaxed…
Multiple studies in different settings have consistently shown that infection with SARS-CoV-2 and vaccination each result in a low risk of subsequent infection with antigenically similar variants for at least 6 months. Numerous immunologic studies and a growing number of epidemiologic studies have shown that vaccinating previously infected individuals significantly enhances their immune response and effectively reduces the risk of subsequent infection, including in the setting of increased circulation of more infectious variants.