Virology News

The 2009 swine-origin H1N1 influenza, though antigenically novel to the population at the time, was antigenically similar to the 1918 H1N1 pandemic influenza, and consequently was considered to be [ldquo]archived[rdquo] in the swine species before reemerging in humans. Given that the H3N2 is another subtype that currently circulates in the human population and is high on WHO pandemic preparedness list, we assessed the likelihood of reemergence of H3N2 from a non-human host. Using HA sequence features relevant to immune recognition, receptor binding and transmission we have identified several recent H3 strains in avian and swine that present hallmarks of a reemerging virus. IgG polyclonal raised in rabbit with recent seasonal vaccine H3 fail to recognize these swine H3 strains suggesting that existing vaccines may not be effective in protecting against these strains.

Vaccine strategies can mitigate risks associated with a potential H3N2 pandemic in humans.

SHANGHAI/HONG KONG (Reuters) - Chinese authorities slaughtered over 20,000 birds on Friday at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six,...

LONDON  - Scientists have worked out how a deadly new virus which was unknown in humans until last year is able to infect human cells and cause severe, potentially fatal damage to the lungs. The finding, published in the journal Nature, came as the...

It has been described as one of the world’s most lethal flu viruses.

More than 20 people have already died from it in China, and more than 100 are infected.

The new strain of bird flu, the H7N9, has caused such a stir in the medical field that local practitioners are on a drive to educate South Africans on the importance of getting flu vaccines.

“This strain is actually nothing new, but the virus is changing itself… it’s becoming bigger and it is absolutely critical that everyone be vaccinated. It doesn’t appear that any South Africans have contracted or are in danger of the virus. but flu spreads quickly, and while we don’t want to scare people, there needs to be awareness,” said Professor Lynne Webber, head of the medical virology department at the University of Pretoria.

Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: “cold-dry” and “humid-rainy”. For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11–12 g/kg and 18–21°C during the year, influenza activity peaks during the cold-dry season (i.e., winter) when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. These findings provide a simple climate-based model rooted in empirical data that accounts for the diversity of seasonal influenza patterns observed across temperate, subtropical and tropical climates.

Last September a doctor in a Saudi hospital was fired for reporting a new, deadly strain of the coronavirus.