 For more videos on people's struggles, please subscribe to our YouTube channel. Pharma companies are now racing to develop a new vaccine which can specifically target the Omicron variant of the COVID-19 virus. This gives rise to the question, can scientists develop a single vaccine which can deal with multiple virus variants, including new variants that may arise in the future? What stands in the way of creating this universal vaccine? Immunologist Dr. Satyajit Rath talks about the future of vaccines. One of the issues that has come up with the current phase of the COVID-19 pandemic is what is the future of vaccines? This has been brought into a general public notice in part because there are reports that companies are now racing to develop an Omicron strain specific vaccine for future COVID usage. The question that arises is, how do vaccine makers, how does vaccinology as a science and technology deal with the emergence of new virus strains, new bacterial strains against which next generation vaccines are to be generated? What are the strategies involved and how are they designed? So, we already have examples of vaccines that cover multiple strains. The straightforward example is the example of the oral polio vaccine which covers three different strains of polio virus. In bacterial infections, pneumococcal vaccines that work against a bacterium that causes pneumonia started out as a vaccine against four strains, then seven, 10, 12. So, now the current vaccines are some 12 or 14 strain covering. The methodological approach, how this is done, is relatively straightforward. To take the COVID example, what ends up happening is a COVID virus protein allows the virus to stick to cells and to enter cells and set up infection. If that part of the COVID spike protein can be covered with antibodies, then infection will not happen. So, what vaccines have is primarily that part of the COVID virus spike protein as a vaccine formulation so that the body makes antibodies that block this interaction. The catch is, in the case of the COVID virus, that because we have maintained physical distancing, there is a steady emergence of virus variants, new strains of virus that have changes that allow the virus to stick to cells better and better. And in order to stick to cells better and better, the changes are most likely going to be in the same part against which antibodies will provide protection, which means that last year's version of the spike protein will generate antibodies that may not provide good protection against this year's version. So, the straightforward argument that has been used for multivalent proteins is to take as many different versions of the protein as possible, representing as many strains as possible, put all of them into a vaccine, make a multivalent vaccine and use that. This is what the polio vaccine does. This is what the pneumococcal vaccine does. The limitation is that this is a strategy that will work for the strains that we know about. What about strains that will emerge in the future that we don't know about? And that is the second pathway that scientists and technologists are attempting in order to develop a more universal or conserved vaccine for COVID-19. And there, the argument is as follows. If the COVID-19 virus spike protein binds and if various versions of the spike protein from different strains bind simply to the same target on ourselves but better and better, then there must be some shape in all these versions that is common that is important for binding to, after all, the same target. Can we identify, can scientists, can structural biologists identify this common structural motif as it were, this common basic pattern as it were? Can they extract it from the other loops and bells and whistles of the variations? And can we use just that conserved pattern in a vaccine so that the antibodies generated against it will essentially block any version of the virus spike protein from binding to the center? This is not easy or straightforward. This is a major scientific problem. It's not simply a technological problem. Structural biologists and immunologists are struggling with this problem and they are optimistic because they think that they can see pathways ahead. But this is still early days for that kind of discovery. And therefore, while multivalent vaccines will be a reality, this conserved universal vaccine is a much more uncertain outcome in the generations of COVID-19 vaccines to come. The final point in this universal vaccine scenario is that it's not as if every time you inject a protein, the body responds afresh to that protein. After all, all of us have been immunized by now with one version of the protein. So our responses are already shaped by our prior experience. Do those shaped responses make a difference to how we will respond to a universal vaccine that the scientific technological communities of the Global North tend to treat as an original antigenic sin as a problem in immunology? Whether prior experience redirects antibody responses to later exposures. And that, as all of us can imagine, is going to be an additional difficulty and uncertainty about making a universal vaccine. These are the difficulties of universal vaccines. So what we have currently to look forward to is, number one, multivalent vaccines. And number two, a public health, public good global inclusive effort to monitor virus outbreaks and the emergence of new strains to evaluate new strains for their properties of characteristics of concern and to connect all of this to a public good approach to vaccine development so that new generation vaccines can be developed and deployed in the public interest as a social good. This is the scenario for today for all of us to think about so much for this week.