Pandemic unpreparedness?

6SLN-lipo PGA specifically catches (coats) human influenza virus and synergizes neuraminidase-targeting drugs for human influenza therapeutic potential

OBJECTIVES

The purpose of this study was to develop a new compound to overcome influenza epidemics and pandemics as well as drug resistance.

METHODS

We synthesized a new compound carrying: (i) Neu5Acα2-6Galβ1-4GlcNAc (6SLN) for targeting immutable haemagglutinins (HAs) unless switched from human-type receptor preference; (ii) an acyl chain (lipo) for locking the compound with the viral HA via hydrophobic interactions; and (iii) a flexible poly-α-L-glutamic acid (PGA) for enhancing the compound solubility and for coating the viral surface, precluding accessibility of the PGA-coated virus to the negatively charged sialic acid on the host cell surface.

RESULTS

6SLN-lipo PGA appears to subvert binding of pandemic H1 and seasonal H3 HAs to receptors, as assessed by using guinea pig erythrocytes, which is critical for virus entry into host cells for multiplication. It shows high potency with IC50 values in the range of 300-500 nM against multiplication of both influenza pandemic H1N1/2009 and seasonal H3N2/2004 viruses in cell culture. It acts in synergism with either of the two FDA-approved neuraminidase inhibitor (NAI) clinical drugs, zanamivir (Relenza(®)) and oseltamivir carboxylate (active form of Tamiflu(®)), and it has the potential to aid NAI drugs to achieve complete clearance of the virus from the culture.

CONCLUSIONS

6SLN-lipo PGA is a new potential candidate drug for influenza control and is an attractive candidate for use in combination with an NAI drug for minimized toxicity, delayed development of resistance, prevention and treatment with the potential for eradication of human influenza.

Pandemic response lessons from influenza H1N1 2009 in Asia

During April 2009, a novel H1N1 influenza A virus strain was identified in Mexico and the USA. Within weeks the virus had spread globally and the first pandemic of the 21st Century had been declared. It is unlikely to be the last and it is crucial that real lessons are learned from the experience. Asia is considered a hot spot for the emergence of new pathogens including past influenza pandemics. On this occasion while preparing for an avian, highly virulent influenza virus (H5N1 like) originating in Asia in fact the pandemic originated from swine, and was less virulent. This discrepancy between what was planned for and what emerged created its own challenges. The H1N1 pandemic has tested national health-care infrastructures and exposed shortcomings in our preparedness as a region. Key health challenges include communication throughout the region, surge capacity, access to reliable information and access to quality care, health-care worker skills, quality, density and distribution, access to essential medicines and lack of organizational infrastructure for emergency response. Despite years of preparation the public health and clinical research community were not ready to respond and opportunities for an immediate research response were missed. Despite warm words and pledges efforts to engage the international community to ensure equitable sharing of limited resources such as antivirals and vaccines fell short and stockpiles in the main remained in the rich world. This manuscript with authors from across the region describes some of the major challenges faced by Asia in response to the pandemic and draws lessons for the future.