Pandemic influenza A(H1N1)v viruses currently circulating in New Zealand are sensitive to oseltamivir

New Zealand, like other southern hemisphere countries with a temperate climate, has been in the winter period with seasonal influenza activity. New Zealand has also experienced a dramatic increase in the number of cases of pandemic influenza A(H1N1)v virus. Early reports from the northern hemisphere at the beginning of the pandemic showed that the virus was sensitive to the antiviral drug oseltamivir. In this study we report that pandemic influenza A(H1N1)v viruses currently circulating in New Zealand are sensitive to oseltamivir, but seasonal influenza A(H1N1) viruses – the co-circulating predominant seasonal strain, is resistant to oseltamivir.

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The impact of the pandemic influenza A(H1N1) 2009 virus on seasonal influenza A viruses in the southern hemisphere, 2009

Eurosurveillance ◽

10.2807/ese.15.31.19631-en ◽

2010 ◽

Vol 15 (31) ◽

Author(s):

C C Blyth ◽

A Kelso ◽

K A McPhie ◽

V M Ratnamohan ◽

M Catton ◽

...

Keyword(s):

Southern Hemisphere ◽

Pandemic Influenza ◽

Influenza A ◽

Seasonal Influenza ◽

World Health ◽

Influenza A Viruses ◽

Complete Replacement ◽

Influenza A H1n1 ◽

The Impact ◽

Pandemic Wave

Data collected over winter 2009 by five World Health Organisation National Influenza Centres in the southern hemisphere were used to examine the circulation of pandemic and seasonal influenza A strains during the first pandemic wave in the southern hemisphere. There is compelling evidence that the pandemic influenza A(H1N1) 2009 virus significantly displaced seasonal influenza A(H1N1) and, to a lesser extent, A(H3N2) viruses circulating in the southern hemisphere. Complete replacement of seasonal influenza A strains, however, was not observed during the first pandemic wave.

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Effectiveness of the 2009 seasonal influenza vaccine against pandemic influenza A(H1N1)2009 in healthcare workers in New Zealand, June-August 2009

Eurosurveillance ◽

10.2807/ese.16.02.19761-en ◽

2011 ◽

Vol 16 (2) ◽

Author(s):

S Jefferies ◽

D Earl ◽

N Berry ◽

T Blackmore ◽

S Rooker ◽

...

Keyword(s):

New Zealand ◽

Influenza Vaccine ◽

Pandemic Influenza ◽

Healthcare Workers ◽

Influenza A ◽

Seasonal Influenza ◽

Seasonal Influenza Vaccine ◽

Binary File ◽

Influenza A H1n1

Binary file ES_Abstracts_Final_ECDC.txt matches

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Enhanced influenza surveillance on Réunion Island (southern hemisphere) in the context of the emergence of influenza A(H1N1)v

Eurosurveillance ◽

10.2807/ese.14.23.19239-en ◽

2009 ◽

Vol 14 (23) ◽

Cited By ~ 8

Author(s):

E D’Ortenzio ◽

C Do ◽

P Renault ◽

F Weber ◽

L Filleul

Keyword(s):

Public Health ◽

Southern Hemisphere ◽

Influenza A ◽

Seasonal Influenza ◽

Winter Season ◽

Influenza Surveillance ◽

Reunion Island ◽

Influenza A H1n1 ◽

Influenza Activity ◽

Réunion Island

With the winter season on the southern hemisphere that starts in Réunion Island in June seasonal influenza activity usually increases shortly afterwards. The new influenza A(H1N1)v virus is rapidly spreading worldwide and may reach the island during the coming winter season. We have therefore enhanced influenza surveillance to detect the introduction of influenza A(H1N1)v, monitor its spread and impact on public health and characterise potential viral changes, particularly if seasonal influenza A(H1N1), resistant to oseltamivir, co-circulates with A(H1N1)v.

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Hospitalized Children with 2009 Pandemic Influenza A (H1N1): Comparison to Seasonal Influenza and Risk Factors for Admission to the ICU

PLoS ONE ◽

10.1371/journal.pone.0015173 ◽

2010 ◽

Vol 5 (12) ◽

pp. e15173 ◽

Cited By ~ 50

Author(s):

Dayanand Bagdure ◽

Donna J. Curtis ◽

Emily Dobyns ◽

Mary P. Glodé ◽

Samuel R. Dominguez

Keyword(s):

Risk Factors ◽

Pandemic Influenza ◽

Influenza A ◽

Seasonal Influenza ◽

Hospitalized Children ◽

Influenza A H1n1

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Contemporary Seasonal Influenza A (H1N1) Virus Infection Primes for a More Robust Response To Split Inactivated Pandemic Influenza A (H1N1) Virus Vaccination in Ferrets

Clinical and Vaccine Immunology ◽

10.1128/cvi.00247-10 ◽

2010 ◽

Vol 17 (12) ◽

pp. 1998-2006 ◽

Cited By ~ 11

Author(s):

Ali H. Ellebedy ◽

Thomas P. Fabrizio ◽

Ghazi Kayali ◽

Thomas H. Oguin ◽

Scott A. Brown ◽

...

Keyword(s):

Influenza Virus ◽

Pandemic Influenza ◽

Influenza A ◽

Seasonal Influenza ◽

H1n1 Virus ◽

H1n1 Influenza ◽

Influenza Viruses ◽

Inactivated Vaccine ◽

H1n1 Influenza Virus ◽

Influenza A H1n1

ABSTRACT Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to achieve human-to-human transmission. In April 2009, cases of a novel H1N1 influenza virus in children in the southwestern United States were reported. It was retrospectively shown that these cases represented the spread of this virus from an ongoing outbreak in Mexico. The emergence of the pandemic led to a number of national vaccination programs. Surprisingly, early human clinical trial data have shown that a single dose of nonadjuvanted pandemic influenza A (H1N1) 2009 monovalent inactivated vaccine (pMIV) has led to a seroprotective response in a majority of individuals, despite earlier studies showing a lack of cross-reactivity between seasonal and pandemic H1N1 viruses. Here we show that previous exposure to a contemporary seasonal H1N1 influenza virus and to a lesser degree a seasonal influenza virus trivalent inactivated vaccine is able to prime for a higher antibody response after a subsequent dose of pMIV in ferrets. The more protective response was partially dependent on the presence of CD8+ cells. Two doses of pMIV were also able to induce a detectable antibody response that provided protection from subsequent challenge. These data show that previous infection with seasonal H1N1 influenza viruses likely explains the requirement for only a single dose of pMIV in adults and that vaccination campaigns with the current pandemic influenza vaccines should reduce viral burden and disease severity in humans.

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