Focus swine flu fight on kids, researchers say

As Canadian health officials grapple with plans to combat a potential swine flu outbreak this fall, a major new study suggests a can't-miss strategy to prevent its spread: Make sure the (school) kids are all right.

In a paper published today in the journal Science, U.S. researchers say mass inoculations of elementary and high school students – and their parents – would knock out key breeding grounds for any form of flu.

And cooling these cauldrons of communicable disease would prevent many of those most imperilled by flu – the very young and elderly – from catching it in the first place.

It's an idea that intrigues one of Canada's top influenza experts, who will likely offer it as an option at a Health Canada meeting next week to hammer out a strategy for the H1N1 flu.

"What I find interesting about this (paper) is that they're really focusing on the fact that young kids are the incubators of this," says Dr. Michael Gardam, head of infections disease control at Ontario's Agency for Health Protection and Promotion.

"I like to call (kids) viral culture media on legs. That is their purpose in life, to get infected with things."

Gardam says kids, in turn, infect their parents, who take the viruses to workplaces, stores, theatres and old age homes. 

Therefore, priority targeting of these two groups for flu vaccinations is the best way to keep major outbreaks at bay, the paper's lead author says.

"We were expecting more delicate results – that in this situation you should do this, and in this situation you should do that," says Jan Medlock, a mathematician at South Carolina's Clemson University.

But no matter the quality or amount of vaccine you have, or the type of flu you're dealing with, the school strategy would work best to halt the spread and save lives, Medlock says.

The study used mathematical modelling from surveys and two prior influenza pandemics, 1918 and 1957, to determine optimal vaccination ages, he says.

Looking at death and infection rates, years of life lost and economic costs, Medlock found that inoculating children aged 5 to 19 (largely students) and adults aged 30 to 39 (key parenting years) would stop the spread most effectively and with the fewest number of shots.

Most flu vaccine campaigns have instead focused mainly on toddlers and older people.

Factory logjam could delay some swine flu shots

Faced with an unexpected delay, health officials are trying to counter new problems with swine flu vaccine production including a logjam at factories that put the precious liquid into syringes.

The newest calculations show the nation won't have the long-promised 120 million doses ready to dispense by Oct. 15, but just 45 million instead. It appears to be more of a delay than a shortage: More are expected to arrive rapidly, about 20 million doses shipped every week, according to the latest estimates by the Department of Health and Human Services.

"Hopefully there are ways to bring that number up," Dr. Robin Robinson, the department's chief of vaccine procurement, said Tuesday.

"We're trying to bring on more manufacturing" for the final packaging step, he said, such as having companies that finish first share their facilities with stragglers.

Swine flu vaccinations still are planned for mid-October, and Robinson noted that 45 million doses means a lot of people inoculated. Add in the weekly deliveries, and there should be 85 million doses on hand by October's end, and the full 195 million the government has ordered by December, the long-set date for final delivery.

But he acknowledged that if there are early outbreaks in September and October, there could be higher-than-anticipated demand for the swine flu vaccine.

"As we've all along said, if things can go wrong they will," Robinson said.

Manufacturers around the world revealed in July that they were having serious problems brewing vaccine. The chief ingredient is grown in eggs, and companies were getting far fewer doses per egg than they usually do for regular winter flu vaccine.

Health authorities have delivered new "seed strains" of the virus to manufacturers to help with that problem, Robinson said.

In addition to the packaging logjam, other factors are adding to the delay, including:

- One manufacturer, Sanofi-Pasteur, took longer than expected to finish brewing the regular winter flu vaccine, delaying the swine flu work, Robinson said. "We knew there were problems," but only recently the extent of them, he said.

- Another supplier, Australia's CSL, recently notified the U.S. that its shipments would arrive later than promised because it first must provide batches to its home country, where the flu season is winding down. Although the U.S. signed a contract with CSL first, "there was always the possibility they could do that," Robinson said. "Our laws can do the same thing. We don't, but we could."

- And it took health authorities longer than anticipated to develop the tests, called reagents, required to ensure doses are at the proper strength before they're cleared for use.