The World Health Organization, the United Nations health agency, uses a system of six phases to warn of possible influenza pandemics.

VOA: special.2009.05.06

In the United States, cases of suspected influenza are at higher numbers than usual this early in the flu season.

VOA: special.2009.11.24

Frank Ruhli says studies like this can prove useful in the fight against H1N1, another form of the influenza virus.

VOA: special.2010.06.29

His team is also attempting to produce new food oils and make synthetic parts of every known influenza virus.

VOA: special.2010.07.20

The World Health Organization this week declared the first pandemic, or worldwide spread, of influenza in forty-one years.

VOA: special.2009.06.13

Evidence is increasing that common influenza viruses are becoming resistant to the main drug used to treat them.

VOA: special.2009.03.04

The W.H.O.has an influenza warning system in which phase six means that a pandemic is taking place.

VOA: special.2009.06.10

They have been used to study cancer,AIDS,genetic testing, and drugs for illnesses including influenza,herpes and Parkinson's disease.

VOA: special.2010.07.21

The World Health Organization will not declare an influenza pandemic unless a virus becomes widespread in at least two areas of the world.

VOA: special.2009.05.06

In the past,children have died or suffered permanent harm from Reye's Syndrome during widespread influenza attacks.

VOA: special.2009.10.20

Swine flu is a respiratory sickness caused by an influenza virus that mainly infects pigs.

VOA: special.2009.04.29

And the best form of prevention, she says,is getting vaccinated each year against influenza.

VOA: special.2009.03.04

But experts say it has become the leading influenza virus in all countries.

VOA: special.2009.11.11

The current spread of a swine influenza virus has added to these concerns.

VOA: special.2009.07.14

Pregnant women face an increased risk even during outbreaks,or periods, of seasonal influenza.

VOA: special.2009.08.18

More than twenty countries have found cases of the new H1N1 influenza virus.

VOA: special.2009.05.06

Next comes using them to develop drugs to fight and treat influenza.

VOA: special.2009.03.04

Pregnant women face an increased risk even during outbreaks of seasonal influenza.

VOA: special.2009.08.05

Meanwhile,expedited efforts are going forward on several continents to develop an effective vaccine for the new strain of influenza.

VOA: standard.2009.04.30

Each year,scientists work to develop a unique influenza vaccine to protect people against the strain expected in the coming flu season.

VOA: standard.2010.07.21

"It is quite possible with an influenza virus, a pandemic influenza virus that it gets worse over time.

VOA: standard.2009.04.30

Now,a team of U.S.scientists think they're on track to developing a "universal" vaccine that will protect people against all kinds of influenza.

VOA: standard.2010.07.21

Health officials in Mexico and the United States were puzzled by a virus that combined elements of swine, avian and human influenza.

VOA: standard.2009.12.25

The nation's fragile public health system also is struggling to cope with a rising number of influenza cases.

VOA: standard.2009.09.14

Operations for people were postponed because facilities and medical practitioners were preoccupied and needed to serve influenza like diseases or flu in particular,".

VOA: standard.2009.09.04

The worst may be over,". "But,it would be unwise for anybody to reach firm conclusions before April, when the normal influenza season usually ends.

VOA: standard.2010.01.18