Interview exclusive de Roberto Bruzzone, co-directeur, HKU-Pasteur Research Pole

Richard Burton, membre du conseil d’administration de France Hong Kong Business Association rencontre Roberto Bruzzone, co-directeur du pôle de recherche de HKU Pasteur à Hong Kong.

Richard Burton: Institut Pasteur is one of the leading institutions in the world for infectious diseases. How has your presence in Hong Kong and China helped you in understanding Covid-19 better?

Roberto Bruzzone: The SARS outbreak was a tipping point in the appreciation of the risk posed by infectious disease to our societies. I dare say that SARS was more of a game changer than AIDS for number of reasons that it would be too long to analyze here, or perhaps it completed the process started with AIDS. The HKU-Pasteur lab switched the focus of its research to emerging viruses after the 2003 outbreak, a choice that has placed the Institut Pasteur International Network and us at the forefront of an early warning and response to emerging disease threats by operating in Hong Kong, where some of the last pandemic threats have originated. The city and the academic environment have been always very attentive to the importance of developing effective strategies to mitigate the impact of infectious diseases. Many groups in Hong Kong are leaders in this field and this give you a more in-depth understanding of the many aspects that are involved in containing outbreaks.

 

Richard Burton: How big a risk is there of a second and more deadly second wave? Are countries opening up too soon?

Roberto Bruzzone: This virus will likely become endemic. I cannot see how we can eradicate a virus that causes infections that are for the vast majority asymptomatic or pauci-symptomatic. It is estimated that more than 90% of infected individuals are not detected and, hence, the virus is currently circulating. Therefore, there will be other waves and we can expect to have a new seasonal respiratory virus that will be added to the current list of influenza, RSV and other coronaviruses, to name a few. Therefore, countries should open up because the virus will always be there. We can use the knowledge accumulated over these months to monitor cases in the community and the resilience of the health system, which I hope will have been strengthened in the meantime. I would like to add that every year there are roughly 400,000 (yes you read well, four hundred thousand) deaths due to seasonal influenza, despite the availability of an underused vaccine, and countries do not shut down to mitigate its impact.

 

Richard Burton: Realistically how close are we to a vaccine? Will it be available next year? What will be its use if the virus has mutated?

Roberto Bruzzone: Realistically I do not think that it will be possible to have a vaccine that will have passed all the stringent tests needed to bring it to the market and we should not put too many of our expectations into the development of a vaccine at breakneck speed. This is a very important point: cutting corners to bring to the market a vaccine without the customary lengthy and necessary precautions would cause a backlash, if serious side effects appeared, with consequences that would reverberate well beyond the control of Covid-19. Even with a vaccine, will vaccination be mandatory? Will people be forced to use a vaccine based on recombinant technology (injection of foreign RNA), which is one of the platforms considered to be very advanced, even when many individuals do not want to eat genetically modified tomatoes?  Expect huge legal challenges! In addition, we have NEVER had a vaccine against a coronavirus, and it is not clear to me why the first one should be very effective. Again, I have to remind that we have had a vaccine against influenza for eighty years and it is not yet perfect (certainly not comparable to the measles vaccine, for instance) despite all that we know on the virus. However, an OK vaccine is better than no vaccine at all. We know that when the influenza vaccine strain selection is not perfect, due to virus mutations, there is a spike in the number of deaths, which proves that the vaccine is helping mitigate the impact of influenza. For example, in the winter of 2018 in Hong Kong there were roughly 600 excess deaths due to influenza, according to a very authoritative study published by the School of Public Health at HKU. This figure is higher than what was reported during SARS in 2003 (286 people died during that outbreak) and manifold more than the total number of deaths by influenza and Covid-19 in 2020: 120 of influenza and 4 (yes four) of Covid-19 in Hong Kong. Regarding the possibility that SARS-CoV-2 may mutate, this will happen, as it is the viruses’ nature and their only chance to survive the selection pressure of our immune system. The good news is that coronaviruses mutate less frequently than influenza because of their genetic makeup that includes a proofreading enzyme to ensure faithful replication of their RNA genome. SARS-CoV-2 seems pretty stable at the moment.

 

Richard Burton:  Is it likely we will see other viruses of this sort in the future? How can we limit that risk? 

Roberto Bruzzone: It is clear that zoonoses are going to exist because viruses and bacteria and many animals were here well before us, so we need to learn to live together, co-exist with them. Louis Pasteur famously said: “Gentlemen (women were rare in scientific meeting at that time), microbes will always have the last word”. This should not be interpreted as a pessimistic outlook; simply a realistic consideration from a well-informed scientist. We have to move on. Covid-19 is a serious disease with which we can co-exist taking some precautions that will not destroy the lives of many people.