Recent Covid-19 infections and the unvaccinated

[shunyadragon]

That's not what herd immunity means Shunya.

It was sarcasm concerning the misuse of the concept of herd immunity. You would understand if you read my next post.

[rogue06]

While the MSM seeks to focus attention on white evangelicals who haven't been vaccinated they only do so to take the spotlight off the largest group of unvaccinated. Blacks. In fact, we're starting to hear whining from the left about a black/white vaccination rate gap and demands that this needs to be addressed. Of course those complaining haven't offered any suggestions of their own.

[Sparko]

Among the vaccinated.

That's not what herd immunity means Shunya.

[shunyadragon]

So this study shows that there is no benefit for previously infected people to get the vaccine.

https://www.medrxiv.org/content/10.1....01.21258176v2

Background The purpose of this study was to evaluate the necessity of COVID-19 vaccination in persons previously infected with SARS-CoV-2.

Results Among the 52238 included employees, 1359 (53%) of 2579 previously infected subjects remained unvaccinated, compared with 22777 (41%) of 49659 not previously infected. The cumulative incidence of SARS-CoV-2 infection remained almost zero among previously infected unvaccinated subjects, previously infected subjects who were vaccinated, and previously uninfected subjects who were vaccinated, compared with a steady increase in cumulative incidence among previously uninfected subjects who remained unvaccinated. Not one of the 1359 previously infected subjects who remained unvaccinated had a SARS-CoV-2 infection over the duration of the study. In a Cox proportional hazards regression model, after adjusting for the phase of the epidemic, vaccination was associated with a significantly lower risk of SARS-CoV-2 infection among those not previously infected (HR 0.031, 95% CI 0.015 to 0.061) but not among those previously infected (HR 0.313, 95% CI 0 to Infinity).

Conclusions Individuals who have had SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before.

No mention of different strains though.

New strain from the UK possibly from India represents ~6% new cases in USA apparently spread to UK than the USA, Other new strains identified India.

Source: https://www.medpagetoday.com/special-reports/exclusives/92345

India's COVID-19 Variant: What We Know So Far

— Not yet clear how much the current surge is driven by this new variant


by Veronica Hackethal, MD, MSc, Enterprise & Investigative Writer, MedPage Today April 29, 2021

As COVID-19 cases overwhelm hospitals in India, a new coronavirus variant has emerged.

Dubbed the "double mutant" variant and announced barely one month ago, already researchers are trying to figure out whether it could be causing the surge in cases -- and what that could mean for the rest of the world.

"We need to keep a close eye on this variant," Katelyn Jetelina, PhD, MPH, of the University of Texas Health Science Center at Houston, wrote in a recent email newsletter.

Why "Double Mutant"?

Its official name is B.1.617, and the "double mutant" is a bit of a misnomer, because it actually carries 13 mutations, 7 of which are in the spike protein. But the moniker comes from two notable mutations found in other variants that appeared together for the first time in this new strain: the L452R mutation and the E484Q mutation.

The L452R mutation in the spike protein was first found in the COVID-19 variant detected in California. One study found that the California variant carrying this mutation may be up to 20% more transmissible than wild-type strains.

The E484Q mutation is notable because it appears to be very similar to the E484K mutations found in the B.1.351 (South African) and P.1 (Brazilian) variants. The E484K mutation in these variants is considered an "escape mutation" because it enables SARS-CoV-2 to evade immune protection with monoclonal antibodies, which may decrease the effectiveness of vaccines. So far, though, current vaccines appear to be holding up against these variants, according to Jetelina.

© Copyright Original Source

My sarcastic comment to your post concerning 'herd immunity' needs clarification. Herd Immunlty' is not set concept. It is conditional on many factors. It is dependent on high vaccination rates. The vaccination rate of the USA is generall not that high. Areas of the USA, like the conservative states have very low vaccination rates, therefore no reasonable chance of herd immunity yet.

[shunyadragon]

where's the herd immunity?

Among the vaccinated.

[Sparko]

So this study shows that there is no benefit for previously infected people to get the vaccine.

https://www.medrxiv.org/content/10.1....01.21258176v2

Background The purpose of this study was to evaluate the necessity of COVID-19 vaccination in persons previously infected with SARS-CoV-2.

Results Among the 52238 included employees, 1359 (53%) of 2579 previously infected subjects remained unvaccinated, compared with 22777 (41%) of 49659 not previously infected. The cumulative incidence of SARS-CoV-2 infection remained almost zero among previously infected unvaccinated subjects, previously infected subjects who were vaccinated, and previously uninfected subjects who were vaccinated, compared with a steady increase in cumulative incidence among previously uninfected subjects who remained unvaccinated. Not one of the 1359 previously infected subjects who remained unvaccinated had a SARS-CoV-2 infection over the duration of the study. In a Cox proportional hazards regression model, after adjusting for the phase of the epidemic, vaccination was associated with a significantly lower risk of SARS-CoV-2 infection among those not previously infected (HR 0.031, 95% CI 0.015 to 0.061) but not among those previously infected (HR 0.313, 95% CI 0 to Infinity).

Conclusions Individuals who have had SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before.

No mention of different strains though.

[TheLurch]

I'm talking more about turning your back on tens of thousands of people crossing the border illegally. If the government willfully turns a blind eye to that international air travel won't matter.

It's not an either/or situation - it's got to be both. While there are undoubtedly other reasons to limit the transit across out southern border, controlling the entry of SARS variants isn't a compelling reason if we're allowing international air travel.

Most of the areas with out of control spread of late have been nowhere near our borders, in any case.

[Stoic]

Then the vaccine does train the immune system to respond to variants?

Not exactly. The immune response is less successful against variants than against the original virus, whether the immune system was trained by vaccines or by infections. It's just that with the vaccines, the immunity goes from 'great' to 'good enough', and with infections, it goes from 'good enough' to 'not good enough'.

And by 'good enough', I mean that once enough people have gained (partial) immunity, the probability of transmission is low enough that the number of cases decreases.

[rogue06]

Well, shutting down all international travel indefinitely (which would be what's needed) has its own costs. And, given that vaccinations in the US appear likely to plateau in the 75% range, we'd have to be prepared for countries to refuse anyone entry from here, as well.

Overall, i'd rather see strong international vaccination programs.

I'm talking more about turning your back on tens of thousands of people crossing the border illegally. If the government willfully turns a blind eye to that international air travel won't matter.

[TheLurch]

That's counter intuitive. Unless these vaccines have a mechanism involved that tricks a person's immune system into fighting off variants, I don't understand how it can be more effective.

Conveniently, we just have some science out on this:
https://stm.sciencemag.org/content/e...nslmed.abi9915

[TheLurch]

A very good reason why open borders is not a good policy

Well, shutting down all international travel indefinitely (which would be what's needed) has its own costs. And, given that vaccinations in the US appear likely to plateau in the 75% range, we'd have to be prepared for countries to refuse anyone entry from here, as well.

Overall, i'd rather see strong international vaccination programs.

[rogue06]

This is a pretty accurate simplification.

There's the worry that some combination of mutations exists that does avoid prior immune responses but still functions for cell entry. That's why getting more people vaccinated will remain a high priority even if we get an effective herd immunity. Having the virus circulating in either unvaccinated populations here or in foreign countries without good vaccine access leaves the door open for additional mutations.

A very good reason why open borders is not a good policy

[rogue06]

China bet big on inactivated viruses as their vaccine technology - both of their first two out the door used this approach. And, as it turns out, it doesn't seem to be an effective one against SARS-CoV-2.

The technique does have a track record for success but apparently not this time. This will serve as a warning for those seeking to place all their eggs in one basket when it comes to things like this. Not only do you need a Plan B (and C, D, E as well), but you better be well into working on it.

[TheLurch]

I think the vaccines work against the variants so far because they specifically teach the body to attack the spike proteins, rendering the virus inert. If the spike protein were to mutate too much, then the virus would be unable to infect our cells. The spike's purpose is to unlock the cell membrane to allow the virus inside the cell to infect it. So most mutations we have seen don't really change the spike protein much because if they did, it wouldn't be able to infect us.

This is a pretty accurate simplification.

There's the worry that some combination of mutations exists that does avoid prior immune responses but still functions for cell entry. That's why getting more people vaccinated will remain a high priority even if we get an effective herd immunity. Having the virus circulating in either unvaccinated populations here or in foreign countries without good vaccine access leaves the door open for additional mutations.

[rogue06]

I think the vaccines work against the variants so far because they specifically teach the body to attack the spike proteins, rendering the virus inert. If the spike protein were to mutate too much, then the virus would be unable to infect our cells. The spike's purpose is to unlock the cell membrane to allow the virus inside the cell to infect it. So most mutations we have seen don't really change the spike protein much because if they did, it wouldn't be able to infect us.

I wonder if part of the success we're seeing in the U.S. has something to do with our using different vaccines that work in different ways.

Of course with reports of those seeking vaccinations dropping sharply in recent weeks (probably assuming they no longer need one), we might be experiencing another wave of the Chicom coronavirus before too long.