The UN health body is figuring out what needs to be done if the viruscontinues to spread and a global response is required, Dr. Keiji Fukuda,assistant director-general for health security and environment said in aninterview from Geneva.

The WHO wants to be ready to make recommendations and issue guidance tocountries if the need arises - though Fukuda stressed at this point it is farfrom certain there will be that need.

"We're very aware that we don't want to over-play or under-play. We're tryingto get that right," says Fukuda, a leading influenza expert.

"(We're) trying to make sure that we're ready to move quickly, if we have tomove quickly, but also trying not to raise alarm bells."

The desire to be prepared without raising alarm is a legacy of the 2009 H1N1pandemic. The WHO was heavily criticized in Europe for declaring that event apandemic when the outbreak turned out to be far milder than originallyfeared.

But what exactly the agency - and the world - might need to prepare for nowis very unclear. With the public relations problems of the 2009 outbreak freshin the minds of health officials, no one is using the "p" word these days.

Yet in some respects the parallels to 2009 are striking.

A new swine-origin flu virus is causing sporadic infections in parts of theUnited States. Since the new virus was first spotted in July, 10 cases have beenconfirmed in Maine, Indiana, Pennsylvania and Iowa. All have been children under10, with a lone exception - a 58-year-old adult. Three of the cases haverequired hospitalization but most of the infections have been mild, like regularflu.

It is an influenza A virus of the H3N2 subtype, a distant cousin of H3N2viruses that circulate in humans.

Scientists at the U.S. Centers for Disease Control say the hemagglutiningene, the H3, looks like that of H3N2 viruses that used to circulate in peoplein the early 1990s.

It is sufficiently different from contemporary human viruses that the H3N2component of the seasonal flu shot is not expected to protect against thisvirus, though it might boost antibody levels in those who were exposed to theearlier H3N2 viruses.

The CDC is still doing serological work - checking stored blood samples forantibodies that react to this virus - to try to figure out how muchvulnerability there is to the new virus. The current thinking is most peopleover the age of 21 or so would have had exposure to similar flu viruses andwould therefore have some protection against it.

Teenagers and children might not, though even that's not 100 per centcertain. Flu expert Malik Peiris, chair of the department of microbiology at theUniversity of Hong Kong, says he thinks exposure to contemporary H3N2 virusesmight provide some protection against these swine viruses.

"It is important to see the serological data to see how much vulnerability orsusceptibility there is in the human population," Peiris says.

Dr. Arnold Monto, a flu expert at the University of Michigan, says if a majorpart of the human population has antibodies that react to the virus, it may notbe much of a threat.

"If there's a lot of immunity in the population, there probably will not beany kind of extensive spread except maybe in these little clusters where youhave little folks who don't have much immunity to anything," he says.

Fukuda, on the other hand, says further spread cannot be ruled out: "I thinkthat certainly there's no reason why this virus, if it continues to spread humanto human couldn't move from country to country among young people."

The first seven infections appeared to have been instances where the viruspassed from pigs to people. But the most recent cases, in Iowa, seem prettyclearly to have involved person-to-person spread.

There were three confirmed cases in that cluster, but it was likely larger.Two contacts of the first confirmed case were also ill, but were not tested. Andthe people in this cluster seemingly had no contact with pigs, suggesting theycaught the virus from an unidentified person.

The virus was previously isolated from pigs in the U.S. Midwest, says Dr.Nancy Cox, head of the CDC's influenza division, though she won't specifywhere.

Canadian authorities say there are no reports of the virus in this country.And the WHO knows of no cases other than those in the United States, Fukudasays.

To some in the flu world, the situation is reminiscent of 1977. That year anH1N1 virus started circling the globe, causing infections mainly in youngpeople. H1N1 viruses hadn't been spotted for 20 years at that point; it iswidely believed the virus was accidentally released from a laboratory.

On some lists of pandemics, the 1977 outbreak is named. Most flu experts,though, do not consider it a pandemic. Some, like Monto, refer to it as a pseudopandemic.

While the flu world doesn't want to over-react to this virus, it doesn't feelsafe ignoring it either.

The CDC asked the laboratory that makes seed strains for vaccine companies toproduce a vaccine candidate virus for this H3N2. It is already in the hands ofmanufacturers.

And the WHO is looking at what it needs to do to be ready. One of the tasksit is currently working on is trying to figure out what to call this virus, ifit should continue to spread.

Naming the pandemic virus was a nightmare for public health officials in thestart of the 2009 outbreak.

Flu experts accustomed to talking about viruses based on the animals theynormally infected - bird flu, swine flu, dog flu, human flu - were caught in apolitical vise when powerful agricultural interests objected to references tothe virus's swine origins.

But calling the virus simply H1N1 didn't differentiate it from the human H1N1that was circulating before the pandemic. (It has since disappeared.) Recentlythe pandemic virus was officially named H1N1 pdm09.

This swine-origin H3N2 virus poses the same naming challenges.

And this time, the WHO wants to be prepared. Fukuda says the WHO has been indiscussion with its animal health counterparts, the UN Food and AgricultureAgency and the OIE, the World Organization for Animal Health, to work out apossible name.

"We're pretty aware that we don't want to increase stigma, we're pretty awarethat it is always possible for people to get afraid of food or to enact tradeembargoes or things like that. So to the extent that naming the virus in a waywhich minimizes those things can be done, we think it's better," he says.

"It's just one of those lessons that we've learned. Take a look at thosethings early. So that's what we're doing."

Still, it's all being done with the realization that there may be no need forheightened public health responses, apart from the increased surveillance theU.S. has mounted.

"This is one of the things that we've discussed," Fukuda says.

"This could be the only cluster we see," he says, referring to the Iowacases. "We could see some sort of stuttering picture for a long time. Or wecould see things jump. All of those things are possible."

https://healthandfitness.sympatico.ca/news/new_flu_virus_has_who_prepping_response/aecada18