Immunity Against Covid-19

We catch about 3 colds a year, so in an average lifetime a UK person will catch about 240 colds. It’s claimed that up to 200 strains of viruses can account for all of these, but in the field many of them are rare, accounting for maybe 1 in 10,000 cases. Of these about 14% of colds are caused by 4 the main strains of coronavirus, so this gives a lifetime effect of catching the same strain of coronavirus 8 times, or once every 10 years. The question is if this is being exposed to it all the time and just catching it on an occasion when our defences against it are particularly weak, or is it a case of it doing the rounds and not being in everyday contact with it, not being immune from it, just taking years to return to the area? Looking at SARS data antibodies are still found after 2 years, but nobody is sure how this equates to immunity or protection.

We have a number of possibilities:

  1. That infection with Covid-19 gives you lifelong immunity to it. People have now been documented to have caught it twice. Also it would be uncharacteristic compared to the coronaviruses previous known for immunity to be permanent. Also there is the problem of what is called ‘long covid,’ which suggests it might not be just a get once and recover occurrence.
  2. That a vaccine will give you lifelong immunity to it from one round of injections. Testing has given immediate figures of around 90-95%. Nobody knows how long term or effective they will be in the field. Other viruses have been eliminated by near permanent mass vaccination but they tended to be ones that luckily had limited infectivity and were not widespread with few mutations. What is thought to be Poliomyelitis is depicted in ancient Egyptian paintings and carvings with the biggest recent outbreak in America being 58,000 cases, with probably in the world of the past a maximum of a million cases a year. With Covid-19 there are so far 60 million cases increasing at about 2.5% a day. We already know of 3 major mutations so far.
  3. Both of the above. Again this is an unlikely possibility given the above.
  4. That a vaccine will give you lifelong immunity to it from yearly injections. If the mutations that will occur don’t happen too fast this is possible.
  5. That an infection will give you about 2 years immunity. This is suggested by data from the SARS study that is a similar coronavirus to Covid-19.
  6. That a vaccine will give you six monthly immunity. This may be possible, but there doesn’t seem to be any records of people catching it again who caught it early on yet. But follow up work needs to be done to find this out, and I can find no records of newly recorded infections to see if they have been cross checked with past infections. If this starts to happen we can work out the longevity and degree of immunity.
  7. That the current vaccines won’t work. This is unlikely given the 90-95% values being suggested. Hopefully using non standard and novel forms of vaccine won’t count against us if the theory is correct, and there are more conventional ones coming on line.  Hopefully they should.
  8. Herd Immunity. With the high numbers of cases though and the fact that it is novel or new, the proposed herd immunity principle is based on past virus vaccination campaigns and virus behaviour over centuries, not months or years. The example quoted of Poliomyelitis was one that has been observed from millennia of exposure and decades of immunisation, and Covid-19 has been known for about a year and is a virus similar to one that causes a disease that has never been cured even now. The theory of widespread unknown prior infection has been losing ground based on actual events and milestones in most countries ever since it was proposed. Some communities are showing numbers as high as 10%, and still increasing at the same rate they were showing when it was only 1% and 0.1%, not signs of widespread immunity, but signs of lack of it.

So we are still left with too many unknowns. Antibody testing has all but ceased, so we cannot be sure who has had the disease in a country. Follow up work seems to be sparse, if at all, so we don’t know how long an effective immunity will last. Vaccines are still waiting to appear, claiming 90-95% effectiveness, but not tested on a population. Since they have not come out we still don’t know how long they will last or if they will work. Percentages of dual and lower dose injections giving better than full doses suggest the theory of immunity isn’t so clear cut, and that a lower dose may give a bigger response, the more you are exposed to the disease pattern reducing your immunity rather than increasing it. The numbers are still steadily going up, so the chance of a novel mutation is getting greater.

Next we come to the logistics. Currently we are told that there is 10 million doses of the first ready to go, so 5 million vaccinations over two separate weeks that are three weeks apart, supposed to roll on the 1st December. Approval hasn’t been given for it yet, so delivery, training and starting to use at full speed to 1,500 sites around the UK is planned for 4 days time. My guess is that it’s unlikely to happen until the end of December.

Next production of the 1st required vaccines will probably take the whole of 2021, the 2nd probably by 2022.

In the UK there are about 25 million people who can be counted as at risk, so as long as one vaccine doesn’t work against the second, reducing immunity overall, what is likely to happen by the end of 2021 or 2022?

The increase in numbers suggest that by the end of 2021 most of the people who have not restricted and distanced will have caught the disease.

If the immunity is only six months or a new mutation arrives then they will need to be re-inoculated before the year is out. If the SARS data is correct then they may have some protection for a couple of years.

Running the numbers of cases against inoculations suggests that even given vaccines, just producing them and getting them to people may take longer than their usefulness. If you’ve already caught the disease how does it compare to the vaccines, and would it be worth also having a vaccine or cause a problem having once caught it, then immunised against it afterwards as well? Hopefully we won’t have the case that the natural immunity that a person gets from having been infected with the disease is reduced by also having a vaccine for that disease.

If you catch it before you get the vaccine, which is likely given the numbers, how many additional different style vaccines will you eventually have for the same thing, and will one affect the other? Closing the stable door after the horse bolted last week.

The 90% effectiveness from what is called a chance discovery of one full dose and 1 half dose of a vaccine being better than from 2 full doses or a single full dose is worrying, and suggests something is happening that is not catered for or the statistics are wrong. Either case may be bad.

Still so many unknowns and claims not backed up by reliable evidence. Only models that may be between 0-100% correct, not knowing whether to put them on the medical or fiction shelf.

It would cost a lot, possibly £2-3 billion, economies of scale and mass production maybe reducing it, but giving everybody in the UK an antibody test would answer a lot of questions that are at the moment pure guesswork. The people against see the exercise as frivolous or pointless but carry on making guesses about numbers, and basing costly decisions on those guesses. A dual test of antibody and antigen would be better, who has or who had the disease, a positive on either giving badly needed information, allowing people to plan a personal and family course of action.

Antigen positive – the person has the disease. Needs follow up. Any subsequent positive antigen test over 2 months later will mean they’ve caught it again.

Antibody positive – the person has had the disease or enough to produce antibodies. Any subsequent positive antigen test over 2 months later will mean they’ve caught it again.

Antibody negative/ Antigen negative – they probably haven’t had the disease and haven’t got it at the moment.

Timing would be critical, probably the 1st Antigen test being done a month before the Antibody one. A positive Antigen test in the past would not need an Antibody test, but taken as Antibody Positive.  All subsequent testing would be antigen as and when required, but at least 2 months later.

This should answer:

Numbers who have had the disease

Numbers who currently have the disease

Numbers who has been re-infected

Proportions in the population

Mortality levels

If re-infected, timings between the two episodes, so potential limits of immunity.

Without it; just guesswork, good, bad or indifferent.

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