Now that every adult in my extended family is vaccinated is my family safe from Covid-19?

The short answer is no.  No vaccine is 100% effective. Yet, we are a lot safer. 

It's a bit hard to work it out in Australia as, although we are familiar with lockdowns, we have so little experience with the actual disease.

The UK and US provide observers with real life modelling. Vaccination with: AstraZeneca; Pfizer; and the other mRNA offerings, is turning out to be a pretty good guarantee against death and perhaps, even, hospitalisation. 

In the United States, of those fully vaccinated, less than 35 people in a million have been hospitalised due to Covid-19 related illness, and of those: less than one in five has died (source: US National Center for Immunization and Respiratory Diseases).

Yet in the US in mid-August 2021 there were around 146,000 new cases per day (seven-day average). 87 thousand, mostly unvaccinated, people were hospitalised and around 975 of these were dying, every day (New York Times - Aug 20, 2021).

As we have repeatedly been told, if 80 percent of the population were vaccinated the virus could no longer spread and the risk would disappear. 'Herd-immunity' will have been achieved. 

Yet there's a problem. 

According to the New York Times (July 23, 2021), a preliminary study in the US estimates the viral load is 1,000 times greater in people with the Delta variant, making it twice as transmissible as the Alpha strain of Covid-19.

Analysis of the virus' spread in the UK (reported in New Scientist: Covid-19: Why we can't count on herd immunity for protection) has found that the Delta variant is from two to four times more transmissible than the Alpha strain. 

As I have previously indicated, successful viruses are shed in vast numbers (see The race for a SARS-CoV-2 vaccine). Virions (virus particles) are so extremely small that they are invisible to light at wavelengths within our visible spectrum. They aren't too hard to destroy as they typically have a lipid outer shell that is vulnerable to solvents like alcohol or soap. Yet, a mote of dust or smoke; or a droplet of water from a breath; is like an entire planet to battalions of virions. And only one needs to get through our defences to infect a vulnerable host cell and begin reproduction within us.

This reproduction employs the infected cell in the host, you or me, to make thousands, perhaps millions, of clones of the successful virion. By capturing the cell's reproductive machinery, it is induced to replicate the virion's core RNA molecule, together with the associated proteins and lipids that surround it.

This reproduction method is subject to error, so viruses constantly mutate. Many copying errors are fatal. If new virions result, they will be unable to infect or replicate. Other reproduction errors have no real impact on the viral success but act as markers that allow contact tracers to identify various mutation strains.

Yet other random copying errors serendipitously improve the virus' reproductive success or enable it to infect a new kind of host. Thus, the original Alpha strain of Covid-19 jumped from and animal to us, as have many other viruses, and has now evolved into the more virulent Delta variant, that sheds its virions at higher levels for longer periods, so that it has been more successful and now dominates.

Thus, it is now estimated that the Delta variant would require 80 to 90 percent of the population to be vaccinated to achieve 'herd-immunity'. This rate exceeds the effectiveness of our current vaccines. So even if everyone on the planet is vaccinated (100 percent) we can't achieve 'herd-immunity' with any of our current vaccines (see New Scientist article above). 

As a result, to get anywhere close to suppression, all age groups will need to be vaccinated, prompting calls for the early approval of the existing vaccines for use with children.

There is also a race against potential mutations that, like the annual influenza virus, may find ways around the immunity conferred by the present group of vaccines (see again: The race for a SARS-CoV-2 vaccine). So, we can expect that new vaccinations will be required in coming years.

In Indonesia many of those medical staff vaccinated with the Chinese Sinovac vaccine, that turns out to be only 50% effective, are now falling ill to the Delta variant, demonstrating that reaching herd-immunity depends on the efficacy of the vaccine used.

The second Chinese vaccine: Sinopharm is still believed to be 79% effective but China is now changing strategy and urgently scaling up mRNA vaccine production in order to near herd-immunity before risking opening its borders (Fortune Magazine - July 17, 2021).

The principal hurdle everywhere remains vaccine hesitancy.

Again, the US provides insights. As I have remarked after our travels there, and most of us are aware anyway, the country is a patchwork-quilt of disparate communities where the prevailing belief systems vary from literal-Biblical, or perhaps, nowadays, literal-Quranic to scientific and rational. Just listen to the car radio as you drive across or down the country.

The community to which a person belongs profoundly effects:

• their preparedness to investigate for themselves, rationally;
• the choice of person in whom to place their trust.

Some of these trusted authorities refuse to accept the relatively new science of vaccination, albeit that it is much older than that enabling their mobile phone.

For me, a mobile phone is material evidence that our knowledge of how the universe actually is, and how this knowledge can be utilised, is already greatly advanced on the knowledge we had when I was a child. To me it is self-evident that this awareness of actual reality, as opposed to myth or speculation, has grown exponentially since mankind's 'new awakening', during the Renascence, leading to the Enlightenment. 

It's striking that those states with the highest religiosity currently correspond to those with the lowest rates of vaccination and thus, at the present time, those with the greatest number of daily deaths.

Seven of these highly religious states (see this link), currently have daily deaths per million of population (averages over 14 days) in excess of 5.1. and two of these: Louisiana and Mississippi, the second and third most religious, have over twice this death rate (together 100 deaths a day). This is over seventeen times the death rate in Massachusetts where 74% are vaccinated. Like several north-eastern states, religious beliefs in Massachusetts more resemble those in the countries of Northern Europe, the UK or Australia and that makes it one of the least religious states in the Union (link).

Yet, in the bible-belt it may not be their religious leaders who are misleading them. It's more likely a communal habit of uncritically believing pseudo-authorities. At the top of this list are: alternative-fact-spruiking politicians; media shock-jocks; and social-influencers.

It's easy to simply throw up one's hands and say: "let everyone do as they like according to their beliefs and let the Devil take the hindmost."

But, as both the US and the UK are discovering, having tens of thousands of unvaccinated people roaming about, continuing to harbour and shed the virus, is putting, even fully vaccinated people at risk, in addition to denying hospital facilities to those with surgical or other urgent needs. 

In Australia, so far, we have kept the spread of Covid-19 at bay, so the unvaccinated have been safe, but this has removed the urgency for them to get vaccinated, particularly when the vaccine itself may present a small risk.

Yet now we appear to be on the edge of the precipice. Our largest city has a persistent and exponentially growing level of untraced infections despite a, now draconian, lockdown. And the Delta variant seems to be popping up all over the country. It's clear that our past, successful, strategy is not succeeding with this new variant and if the trend continues our leaders will have to rethink.

Sooner or later, we will need to let it run and accept that the virus is here to stay. People will die. If this happens too soon, given our present level of vaccination, our death rate will certainly exceed that in the US and UK.

Can we estimate by how much?

According to Our World in Data, the biweekly confirmed COVID-19 deaths per million people, as at August 19, 2021, in the US was 29.5 (where 51% of the population is fully vaccinated - mostly with an mRNA vaccine); while in the UK it was: 19.6 per million (where 61% are fully vaccinated - mostly with AstraZeneca). Both these death rates have more than doubled in the past month, due to increasing abandonment of social distancing.

The vast majority of these deaths are among the completely unvaccinated minority.

Canada, with a long southern border with the US, now has 65% fully vaccinated. The number of biweekly confirmed COVID-19 deaths per million people has also risen slightly to 3.8 per million. On the southern US border, Mexico, with 23.4% fully vaccinated and little social distancing, now has 63.1 biweekly confirmed COVID-19 deaths per million people, an appalling death rate.

Translated to Australia, where only 28.9% are presently fully vaccinated, if social distancing was abandoned now, our death rate would quickly resemble Mexico rather than the UK or US. We could expect our hospitals to be overwhelmed and up to 50 deaths a day.   

So, it doesn't matter if you can only get the very slightly more dangerous, but more readily available, AstraZeneca vaccine. The slight risk to you, and the community, is far less than being among the unvaccinated minority. 

Fortunately, vaccination rates in Australia are accelerating fast (see this link). At this rate we should catch up to the US by around October and the UK by the end of the year.

An issue is the time it takes to become fully vaccinated. Those receiving their first shot this weekend will not be fully vaccinated for up to a month-and-a-half.

So, around Christmas it should be possible; probably inevitable, as cases grow; and very likely essential to Australia's ongoing economic prosperity; to entirely remove social distancing restrictions in all but remaining highly vulnerable, largely unvaccinated, locations. 

Most states in Australia should be ready by then. The exceptions could be Queensland and Western Australia, which may need to impose draconian restrictions for longer due to comparatively low vaccination rates.

This has nothing to do with religion. It's partly due to their initial reluctance to distribute the AstraZeneca vaccine for those under 60, putting at risk many more than the tiny number who may have suffered vaccine related complications.

As in the US and UK, when we move back to normality, deaths will inevitably rise. But these should be manageable from a public health perspective and - not to put too harsh a point on it - it will be many of the victims' own bloody fault. 

So, every Australian hoping for health; happiness; and prosperity in 2022, should aim to be fully vaccinated by Christmas.