Thursday, 10 December 2020

Anti-Covid-19 Vaccines - A Triumph for Science.

Margaret Keenan, 90, becomes first in world to receive Pfizer Covid vaccine outside a clinical trial.
Covid vaccine: UK woman becomes first in world to receive Pfizer jab | World news | The Guardian

Remember the name Margaret Keenan, for she has just made history and will be the answer to trivia quiz questions for years to come. She is the first person outside a clinical trial, to be injected with the first dose of the new SARS-CoV-2 vaccine.

In a slight departure from my usual posts, I publish this one to mark this historic first. It marks a significant milestone in mankind's battle against one of the most deadly and destructive pandemic viruses since the 'Spanish' flu of 1919 and possibly since the black death of the early Middle Ages.

It is also a significant advance in the science of immunology, being the first vaccine produced from the messenger RNA (mRNA) of a virus itself. The section of mRNA is that from the virus' genome that codes for the 'spike' proteins on the virus surface that play a major role in gaining access to the inside of the cell, where it parasitises the cells replicative machinery to make thousands of copies of itself and destroy the cell in doing so.

The vaccine introduces just the mRNA for the 'spike' protein into the cells which then produce just the 'spike' proteins which are recognised by the body's immune system as foreign proteins, stimulating the manufacture of antibodies to the protein and training the T-lymphocytes to attack and destroy virus particles. When an immunised person is infected by the virus, the antibodies attach to its surface and prevent the 'spike' proteins working so the virus cannot gain access to the cell and is rendered harmless.

This particular vaccine, produced by the German company Pfizer in association with the research organization BioNTech, has been shown to be effective in 95% of immunised volunteers, which is an astonishing success rate for any vaccine. However, it has a major technological drawback in needing to be stored at -70oC, making it difficult to be distributed and deployed in the more remote parts of the world. It can only be stored in a normal refrigerator for up to five days.

Also shown here is the open access paper in the Lancet of another anti-Covid-19 vaccine produced by AstraZeneca in conjunction with Oxford University, now awaiting approval by the regulators. This vaccine has the major advantage that it can be stored in a normal refrigerator. This one is reported to be at least 70% effective but, by a mechanism that is not yet fully understood, if the initial dose of the two needed is halved, the result is 95% effective 28 days after the first dose. As with the Pfizer vaccine, the second dose is given 21 days after the first and antibody levels appear to peak at about 28 days. The AstraZenaca/Oxford vaccine uses a harmless adenovirus as the carrier to insert the mRNA into muscle cells at the injection site. AstraZeneca has been contracted by Oxford University to supply the vaccine at cost on a not-for-profit basis, making it accessible to even the poorest countries on a per capita basis.

Religious people might like to note how religion played no part at all in the production of these vaccines, which are a triumph of science and particularly an understanding of genetics and how viruses usurp the cell's replication machinery.

By contrast, fundamentalist of all religions have behaved at times as though they have a mission to spread the virus as widely as possible, holding super-spreader religious services, selling quack cures and telling their followers that their faith alone will protect them. Indeed, some have gone so far as to claim the virus has been sent by God to punish the ungodly (read, anyone who disagree with the priest claiming that) or that measures to control its spread are part of a plot to turn people away from religion.

Some priests are now beginning to actively discourage their followers from having the vaccine, often lying to them, claiming the vaccine is made from the bodies of aborted embryos, or that they can alter your DNA to stop you believing in God and make you gay, and even that they contain monkey genes. mRNA is not capable of changing your DNA and there are no such things as genes for believing in gods. The only genes these vaccines contain are those derived from part of the virus genome which, on their own, are harmless. It seems these frauds have become so inured to the fact that science undermines so much of their religion's dogmas, that many clerics see science as an enemy to be opposed at every turn. Others, for whom greed and self-aggrandizement have becoem their religion, are, as you might expect, deeply concerned that their income stream, their power and their influence will diminish if people don't go to church. To these people, who often pretend to be pro-life, sacrificing human lives to maintain their wealth and influence is a price worth paying, especially if those lives are those of other people.
Doubtless, there will be a rush now to begin thanking God for delivering mankind from the pandemic his fundamentalist believers believe he created in the first place as some sort of punishment for whatever their current hobby-horse is. As usual, religion stands on the side-lines, often jeering and offering nothing but magic spells and apportioning blame, then rushes in to claim the credit when science and technology have done the work.

There are currently some 236 different research programs aimed at producing a vaccine in what must rank as the biggest single project by science in history. These vaccines have been produced in under 12 months - something that would normally take several years to accomplish. So far, three have proven their effectiveness and safety in clinical trials and have either been certified for general use or are currently being assessed for certification.

Hopefully, when enough people are effectively vaccinated to give humanity sufficient herd immunity, the SARS-CoV-2 virus will go the way of poliomyelitis and become extinct. But first we need to immunise 80-90% of the world population and keep on top of any mutations that might make the virus able to resist the antibodies the vaccines produce. One of the major advantages of the mRNA vaccines is that it should be relatively simple to change the mRNA in the vaccine in line with any such mutation. So long as the antibodies can attach themselves to the 'spike' proteins on the virus, they should be as effective.







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