As one of the world’s top influenza experts, Academician Phares has emphasized for many years that not enough attention has been paid to preparing for future influenza pandemics. But when confronted with the possible threat of a pandemic caused by a specific strain of influenza, he has always been able to present a potentially different but ultimately proven correct perspective through a comprehensive and systematic analysis of the arguments based on his profound knowledge. A prime example is that since the 1997 H5N1 avian influenza pandemic in Hong Kong, Academician Phares has been one of the strongest opponents of the hypothesis that H5N1 could cause an influenza pandemic. For more than a decade he has been proven essentially right, and the Hong Kong H5N1 avian influenza has never caused a global pandemic. Theoretically, swine flu is much more likely to cause a pandemic than bird flu, a view shared by Phares. This time, the swine flu has reached the WHO level 5 warning in less than a month from the first confirmed case and has the potential to rise to level 6 (the highest level). Does this prove that the above theory of Phares is correct and indicates that there is indeed a new swine flu pandemic with a hazard equivalent to the 1918 swine flu coming? Academician Phares did not get carried away by the initial validation of his theory, and after a calm and systematic analysis, Academician Phares made his latest prediction in this article in the Wall Street Journal with a convincing scientific basis: the result cannot be that bad, and we have every reason to be more optimistic. Of course, by saying that the current swine flu will not be particularly harmful, Academician Phares is not saying that we should not prevent and control this flu at the moment. Phares’ point could be expressed in a more familiar way: we have a good scientific basis to defy the enemy strategically, but at the same time, we still have to pay attention to the enemy tactically. We should have full confidence that an aggressive, scientific human response can minimize the damage of an influenza pandemic. Academician Phares has been the chairman of the Department of Microbiology at Mount Sinai School of Medicine in New York, USA, for many years. He has been a frequent visitor to China (including Wuhan) since the 1980s, and I did postdoctoral research on influenza in Academician Phares’ laboratory from 1987-1989. In this article in the Wall Street Journal, Academician Phares first summarized the main features of the new H1N1 virus: 1, this swine virus belongs to the same H1N1 subtype as the 1918 pandemic virus. 2, the swine virus can easily achieve interpersonal transmission. Currently, swine virus strains have appeared in 4 continents. Avian influenza H5N1 virus (another virus with pandemic potential) has never been shown to readily achieve human-to-human transmission; humans may be infected with H5N1 viruses directly from chickens, and such infections require large numbers of viruses to achieve. 3. It is unusual for this swine virus to appear in a season other than the one in which they normally appear. Influenza viruses are rarely isolated in the northern hemisphere at the end of April; in New Zealand, where winter has not yet begun, several strains have been reported. 4. Swine viruses can become more pathogenic than they currently exhibit by mutating and/or acquiring new genes from other human or animal influenza viruses. For influenza viruses, mutation and acquisition of foreign genes are naturally occurring processes in which there is no human intervention. Moreover, these processes (and the extent to which they will increase in virulence) cannot be predicted. Phares also tells us why we should be optimistic with a rigorous argument: 1. In 1976, there was an outbreak of H1N1 swine virus in Fort Dix, New Jersey, which had interpersonal transmission but did not end up as a very deadly pandemic strain. 2, The current epidemic swine virus is likely not more virulent than other seasonal influenza strains we have experienced over the past several years. 3. The current swine virus lacks an important molecular signature (the F2 fragment on the viral internal protein PB1), which was present in both the 1918 virus and the highly pathogenic H5N1 avian influenza virus. If this virulence marker is indeed necessary for an influenza virus to be highly pathogenic to humans or to chickens, then the current swine virus lacks the essential conditions to be able to be a major killer. 4. Because humans have been exposed to H1N1 viruses over the past few decades, we may have some cross-immunity against swine H1N1 viruses. Although this immunity may not be sufficient to prevent illness, it is likely to reduce the mortality caused by the virus. Phares reasoned that because of the existence of this “herd immunity” in the population, even if a virus similar to the 1918 H1N1 emerged, it would never have triggered the dire consequences that it once did. The most likely outcome is that the current swine virus will evolve into another (fourth) conventional seasonal influenza strain. 5. The technological platform for vaccines and anti-influenza drugs has improved considerably compared to a few years ago. Based on what we know about the structure and sequence of the swine virus, current FDA-approved drugs and registered vaccines (with minor modifications for the swine flu strain) will be very effective against this new virus. In addition, current technology and production capacity will allow us to have sufficient quantities of swine virus vaccine available nationwide for the winter of 2009-10. Finally, he noted that we have a vastly improved infrastructure to deal with emerging diseases. The various plans and preplans implemented for the H5N1 avian influenza threat have greatly improved the overall surveillance system (without these improved surveillance systems, we may not have detected this swine virus as quickly). The most significant progress is that our government has moved forward with the development of new and improved manufacturing processes, and the development of exciting new vaccines and antiviral drugs is moving forward, with the result that humans have a promising upper hand in the battle against the devious virus. For example, universal flu vaccines (1 vaccine that is effective against all strains over the long term) and broad-spectrum antiviral drugs are being developed in our laboratories and by innovative biotechnology companies. Major funding for this work is being provided by the NIH and CDC. This investment is worthwhile, and the results will reduce the impact of future influenza on citizens’ health and the national economy as a whole. While we should certainly be prudent in preparing for swine flu, it is equally important to maintain a balanced mindset that fully recognizes the capabilities we currently have in place.