Vaccine effectiveness and Herd Immunity

[HappyMan]

Just got the news that the wife has also passed...

How old are the children?
That really sucks, man. My condolences.

 

[dafluff]

How old are the children?
That really sucks, man. My condolences.

The youngest one is 13, and now home alone during the day. The other ones are already married and moved out of the house. One already had Covid, and that one is going to stay with her at night until her self-isolation period is over, then I suppose they'll evaluate the living situation going forward.

 

[Hawk256]

Herd immunity numbers increase to over 80% and as much as 90% with Delta variant. A lot of countries are having trouble with 70%. Not looking good if you are waiting on herd immunity.

Delta Spikes Herd Immunity Threshold to Over 80%: Virus Update

(Bloomberg) -- The spread of the delta coronavirus variant has pushed the threshold for herd immunity to well over 80% and potentially almost 90%, the Infectious Diseases Society of America said.Indonesia is effectively ditching its bid for herd immunity as delta pushes the threshold beyond...

finance.yahoo.com

 

[R Cameron]

Herd immunity numbers increase to over 80% and as much as 90% with Delta variant. A lot of countries are having trouble with 70%. Not looking good if you are waiting on herd immunity.

Delta Spikes Herd Immunity Threshold to Over 80%: Virus Update

(Bloomberg) -- The spread of the delta coronavirus variant has pushed the threshold for herd immunity to well over 80% and potentially almost 90%, the Infectious Diseases Society of America said.Indonesia is effectively ditching its bid for herd immunity as delta pushes the threshold beyond...

finance.yahoo.com

Previous infections should be added to vaccinations to determine overall percentage. It's simple to know the percent vaccinated, and relatively simple to estimate the percentage with previous exposure, the real problem is determining how much those two groups overlap. For example, if an estimated 25% have antibodies from virus exposure, and a known 60% have been vaccinated, there could be anywhere from 60 to 85% with good immunity. I haven't heard of any country tracking this information well, I suppose it would require surveying and giving antibody tests to everyone being vaccinated, and even that wouldn't catch the cases that were asymptomatic or mild many months ago.

 

[El_Goretto]

I suppose it would require surveying and giving antibody tests to everyone being vaccinated

Why everyone? Wouldn't a statistically significant sample suffice?

 

[Balifrog]

Why everyone? Wouldn't a statistically significant sample suffice?

Maybe in a rather small, homogeneous population spread on a small territory it could be. Thinking SGP or HKG.
In countries like Indonesia or Philipines, little chance to get a "representative sample of the country.
For me anyway, too many government plans and decisions were made based on dubious calculations, extrapolation, predictions and other data hocus pocus.

 

[Hawk256]

Previous infections should be added to vaccinations to determine overall percentage. It's simple to know the percent vaccinated, and relatively simple to estimate the percentage with previous exposure, the real problem is determining how much those two groups overlap. For example, if an estimated 25% have antibodies from virus exposure, and a known 60% have been vaccinated, there could be anywhere from 60 to 85% with good immunity. I haven't heard of any country tracking this information well, I suppose it would require surveying and giving antibody tests to everyone being vaccinated, and even that wouldn't catch the cases that were asymptomatic or mild many months ago.

I think it will be hard to know how many have had previous exposure. The CDC in the US has even stopped tracking mild break though cases in the vaccinated, so we can't even track the true number of break though infections. The government doesn't want to know unless you end up in the hospital or dead it appears.

CDC under fire for decision to limit tracking of Covid-19 cases in vaccinated people

The agency’s decision to limit its reporting of breakthrough cases has prompted wide variation in how states keep tabs on them.

www.politico.com

 

[R Cameron]

Why everyone? Wouldn't a statistically significant sample suffice?

True, not necessarily everyone, but many people with care given to ensure it's a representative sample. And it wouldn't need to be extremely precise, just like estimates of total cases (not just positive tests) are imprecise but still useful.

 

[R Cameron]

I think it will be hard to know how many have had previous exposure.

Impossible to know, but the CDC is making estimates: https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html

CDC estimates that from February 2020–May 2021:

1 in 4.2 (95% UI* 3.6 – 4.9) COVID–19 infections were reported.
1 in 3.8 (95% UI* 3.4 – 4.3) COVID–19 symptomatic illnesses were reported.
1 in 1.8 (95% UI* 1.6 – 2.0) COVID–19 hospitalizations were reported.
1 in 1.3 (95% UI* 1.30 – 1.34) COVID-19 deaths were reported.
These estimates suggest that during this period, there were approximately:

120.2 Million
Estimated Total Infections

101.8 Million
Estimated Symptomatic Illnesses

6.2 Million
Estimated Hospitalizations

767,000
Estimated Total Deaths

I had not seen that before just now, personally I find those numbers startling, greater than 36% of US already infected?!

 

[Hawk256]

Impossible to know, but the CDC is making estimates: https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html



I had not seen that before just now, personally I find those numbers startling, greater than 36% of US already infected?!

Roughly 70% vaccinated in the US. How do we apply the 36% to that number to get a total possible immunity number? I don't think we have enough data.

 

[dafluff]

Should come as a surprise to no one, and will likely be adopted by more and more countries.

Exclusive: U.S. developing plan to require foreign visitors to be vaccinated, official says

The Biden administration is developing a plan to require nearly all foreign visitors to the United States to be fully vaccinated against COVID-19 as part of eventually lifting travel restrictions that bar much of the world from entering the United States, a White House official told Reuters on...

www.reuters.com

 

[dafluff]

A research paper from the UK, on vaccine effectiveness against Delta variant.

With the BNT162b2 vaccine, a small difference in effectiveness between variants was seen after the second dose: 93.7% (95% CI, 91.6 to 95.3) with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) with the delta variant. The effectiveness with two doses of the ChAdOx1 nCoV-19 vaccine was lower than with the BNT162b2 vaccine; however, with the ChAdOx1 nCoV-19 vaccine, the difference in effectiveness between the alpha and delta variants was small (74.5% [95% CI, 68.4 to 79.4] and 67.0% [95% CI, 61.3 to 71.8], respectively).

https://www.nejm.org/doi/full/10.1056/NEJMoa2108891

 

[R Cameron]

Roughly 70% vaccinated in the US. How do we apply the 36% to that number to get a total possible immunity number? I don't think we have enough data.

The US is only 49.8% fully vaccinated and 58% with at least 1 dose: https://covid.cdc.gov/covid-data-tracker/#vaccinations

If we estimate the 36% previously infected is distributed proportionally among the vaccinated and unvaccinated population, that would give 15% of the US population with previous infection and no vaccination. But I suspect it's not proportionally distributed because millions of children have been getting infected but zero have been vaccinated, so perhaps 20% of the US population with previous infection and no vaccination. That would make for an estimated range of 73-78% of the US with previous infection and/or at least one vaccination shot.

 

[Hawk256]

The US is only 49.8% fully vaccinated and 58% with at least 1 dose: https://covid.cdc.gov/covid-data-tracker/#vaccinations

You are correct. 70% applies to adults only. The fact that the US is celebrating the 70% mark so greatly must have stuck that figure in my mind. Very few countries have made it to the 70% vaccine mark for total population. Gibraltar, Pitcairn Islands, Malta, UAE, and the Cayman Islands at this point. Very small places with a small overall population.

Coronavirus (COVID-19) Vaccinations

Explore data on COVID-19 vaccinations across the world.

ourworldindata.org

 

[Samoerai]

We will never get to herd immunity whilst people like Balifrog are around. There are enough people who medically cannot take the vaccine and then add in the selfish ones and the numbers will never get high enough.

Balifrog since you think that vaccines dont work how do you explain the difference between UK and Indonesia for last 10 days. As you can see on the twitter feed on the right
"In the last 14 days, Indonesia recorded 598k Covid cases, and the UK recorded 544k, only about 10% fewer than Indonesia.
However, it recorded 96% fewer deaths. (496 vs 13,780).
The difference? The UK has fully vaccinated 53% of its population. Indonesia only 6%."

Is there an explanation in why in Indonesia the population is only 6% vaccinated?

1. Is it of lack of vaccin doses?
Actually, I don't believe that, because according to the news there are more than105 million doses of Sinovac in the country and also 50 million doses of AstraZeneca.

2. Is it of poor coordination?
In Jakarta, I must say, the vaccins programs are well coordinated. Also, I ask around in Jakarta: taxi drivers, gojeks, employees ... everyone I talk to, says "saya sudah divaksin". So, the low 6% is due to low vaccinated population in the rural area's of Indonesia. Is that true? Is there anyone in the forum who can confirm this from their own experience? Are there vaccin centra out there in the desa's? Do people in the desa's have access to vaccins?

3. Is it because the majority of people in the rural are 'afraid' of vaccins?
Are people in the kampongs afraid of the vaccins? Takut? And therefore they do not want to be vaccinated? Is there anyone in the forum who can confirm this from their own experience?

Knowing this, means that we can address the problem more accurate. Right?

 

[Helpful Herbert]

In our kampung in W Java they are all fine with getting the vaccine when asked. However none of them has been asked yet. The only local people to have got vaccinated so far are Pak RT and Pak RW.

The 6% is for those who have received both doses. In total 71m vaccine shots have been given as of today. Around 440m are needed (80% of the population * 2 doses each). They currently do almost 1m/day. So it should take around 13 more months (Sept 2022) to get to 80% herd immunity (quicker if they can do more than 1m/day).

 

[rabbit_39]

Isn't like 33% of Indonesian population in Java?

 

[Balifrog]

@Ruserious,
"Balifrog since you think that vaccines dont work"

Where did I said that ? On the contrary, I said multiple times the opposite !

 

[Balifrog]

Isn't like 33% of Indonesian population in Java?

57% around 150 M

Thank you Google.

 

[rabbit_39]

57% around 150 M

Thank you Google.

Then it's even more difficult for me to understand why Indonesia only has 6% vaccination rate, even for both doses. Assuming anywhere outside of Java is "rural and remote" (not true), and half of Java population are also "rural and remote" (not true), then we have 28.5% of Indonesia's population living in cities and accessible areas. I think Indonesia is doing a better job than administering vaccines only to 20% of the population NOT living in "rural and remote" areas (to get to 6% vaccination rate). But then again these are just top of my head estimates, maybe it is true that Indonesia has only reached 6% vaccination rate, but I'd say that it's not due to people living in remote areas (even if we assume all of them are afraid to be vaccinated), lack of vaccine or poor coordination.

Shrug... I sure hope it's not true that Indonesia has only reached 6% vaccination rate.