Race between vaccination and mutation of virus

The Covid-19 pandemic, globally, has developed into a race between vaccination of the world population and mutations of the virus into more dangerous strains. This, in a way, is a struggle for survival and a case of survival of the fittest. In the history of this planet Earth, such struggles have resulted in the total disappearance of species. In such struggles, human species have been successful in eliminating infectious microorganisms, like Small Pox, Polio, Measles, etc. But new bugs emerge, like HIV, Ebola, SARS, MRSA infections, etc. Mutations are part of the process of evolution of species and natural selection.

If there were no genetic mutations, there would be no life on earth. It is genetic mutations that survive that could produce variants and eventually new species. Out of thousands of mutations, it is a few that survive to produce new strains with new characteristics. And only a few of these characteristics would be capable of being useful for the survival of the organism. Some of these characteristics in microorganisms would be important for us from the health point of view. In the Covid-19 virus, it is mainly the changes in the spike protein of the virus that is of concern, for it is the structure that gives the ability to the virus to gain entry into cells of certain systems in the human body such as the respiratory system. Changes in the spike protein could make it more infectious and cause faster spread of the infection.

Viruses mutate at different frequencies. Some are fast and others are slow. Covid virus mutates slowly and accumulates about two changes per month. These are the stable changes that may assist the virus in its struggle for survival and help it to gain entry into host cells. When billions and billions of viruses in a global pandemic undergo mutations, and they have the potential of accumulating two stable changes per month, the chances of such changes being harmful to the host are high. This is a factor in the race between virus mutations and vaccination. Wider the spread and longer the virus lingers, greater is the chance of a virus victory. Faster the rate of vaccination of human beings worldwide, greater is the chance of a human victory.

Going by the recent picture emerging in countries like the UK, Singapore, Australia, etc., where new variants are gaining ground even though sufficient numbers are said to have been vaccinated, the virus seems to have the edge. This is because in other parts of the world sufficient numbers have not been vaccinated, and there is ample opportunity for the virus to replicate, increase its numbers and numbers of stable mutations and development of variants against which the presently available vaccines are less effective. This has happened in countries where the virus has had a free run, such as Brazil, South Africa, India and Peru.

The virus variants that emerged from these countries have been increasingly more infectious if not more lethal. As the numbers they could infect are greater, the number of deaths is also increased. The variants that have been tagged by WHO as Alpha, Beta, Delta and Lambda in that order are believed to have increased their ability to invade human beings. Whether they are more deadly has not been proved. Yet, their ability to spread much faster than their predecessors, pose a big threat to the vaccination process and creates a greater need for faster vaccination. Further, the successful vaccination in one part of the world does not make it safe for them as the picture unfolding at present shows. Even in Israel, where 80% vaccination was achieved very early, new variants are appearing. This is because, as the WHO Chief said, “no one is safe until everyone is safe”.

However, the good news is that some of the vaccines are proving to be more successful than expected. Particularly the mRNA vaccines like Pfizer are found to be more effective. They are proving to be as effective, if not more, in the real world as they were in clinical trials. For instance, Pfizer and also Moderna, which were expected to be 70-75% effective have been found to be 90-95% effective. It does not always go this way with vaccines. The construction of the mRNA vaccines involves a new technique, where part of the genome responsible for the development of the spike protein of the virus is carried in a harmless virus and used for the inoculation. This has been made possible due to diligent investment in molecular biology research for the last 40 years. These vaccines aim at the spike protein, while traditional vaccines like Sinopharm aim at the whole virus. The former appears to be more effective.

Effectiveness of the available vaccines against variants differs according to the type; but all of them are found to be effective in preventing serious illness and death. Pfizer and AstraZeneca vaccines are found to be 75% and 60% effective respectively, against the Brazil and South African variants in preventing the infection. They may be less effective against the Indian Delta and Peruvian Lambda. This shows that the Covid virus could gain the upper hand over vaccines when given the chance to undergo mutations.

The fact that several countries are lagging behind in the vaccination effort has to be viewed in this background. Though the US, the UK, Europe and other developed countries have succeeded in vaccinating more than 60% of their population, it is still only 8% of the global population that has received the jab. In 60 countries, less than 5% have been given the vaccine. If the emergence of variants totally resistant to vaccines is to be avoided, the global population has to be vaccinated in double quick time. Countries which have the capability of producing vaccines, but do not have the know-how to produce vaccines effective against Covid, should be given access to the technology. Now is not the time to hold on to patency rights. But it appears that the developed countries are driven by commercial considerations and not concerned with the safety of the world. They must realize that they too are in danger. The winner of the race between vaccination and mutation may be decided by what action the developed countries would take, to make available the vaccines to everybody in the world and how quickly that would happen.

N. A. de S. AMARATUNGA