Effect Measure

Sorting out the vaccine puzzle

With flu season in the northern hemisphere looming and H1N1 cutting a nasty swath through good portions of the southern hemisphere’s current flu season, attention is being turned to the non-existent but hoped-for vaccine against swine flu. Yesterday we discussed the problem of pinning pandemic planning on a vaccine. That’s planning for the best, not hoping for the best. There are a lot of uncertainties regarding whether an unadorned egg-based vaccine — the bulk of the vaccine now in development — will be sufficient, available in time or even effective. But those problems just scratch the surface of vaccine unknowns, as a typically excellent piece by Helen Branswell of Canadian Press lays out:

Vaccine manufacturers will do the basic testing, work designed to assure regulators and would-be recipients that their vaccine is safe and likely to protect against the pandemic strain, an H1N1 virus of swine origin.

But there are many other key questions. In fact, the list is too long to tackle in its entirety in the limited time available.

So discussions between planners and regulators over the past few weeks have led to a paring down of priorities.

[snip]

[NIH will reportedly] green-light one looking at whether the pandemic vaccine – to protect against the new H1N1 virus – could be given at the same time as seasonal flu vaccine, which protects against three types of flu viruses including a different H1N1.
Co-administration, as it is called, would make the logistics of pandemic vaccine delivery much easier – if the pandemic vaccine is ready in time. But would giving people vaccines that protect against two different H1N1 viruses at once actually undermine the effort by weakening the response to one or both?

[snip]

In Canada, plans are underway to try to test whether people with egg allergies could be given flu shots containing vaccine produced in eggs. Currently that is considered unsafe and is not done.

[snip]

Dr. Scott Halperin, a vaccinologist from Dalhousie University in Halifax, says a newly formed, federally funded research network hopes to get ethics approval to test the assumption it is unsafe to give people with egg allergies flu shots.

[snip]

“That is a real concern,” he says of the current position on people with egg allergies. “You can’t leave a whole segment of the population without access to protection.”

Another question regulators in the United States and possibly some other countries need answered relates to the use of adjuvant.

Specifically, they’d like to know whether one of the powerful new adjuvants made by companies like GlaxoSmithKline and Novartis could be used with antigen (vaccine) made by a company that currently doesn’t market adjuvants, such as Sanofi Pasteur. (Helen Branswell, Canadian Press)

None of these studies will answer the bottom line question about whatever vaccine or vaccines emerge from the gauntlet of testing and unforeseen contingencies between now and any major ramp up of circulating swine flu, should this occur in the fall (as seems very likely). That question is whether the vaccine will make much of a difference. That’s something we don’t know yet. In theory, it should, but the evidence from seasonal flu is murky.

We won’t know how well it worked until afterward. One hopes that along with plans for a vaccine campaign there are also parallel plans for systematic evaluation of efficacy. One hopes. As always, Hope Springs Eternal.

Comments

  1. #1 Richard Swift
    July 20, 2009

    People with egg allergies could use the Virus-like-Particle (VLP) swine flu vaccine being produced right now by Novavax. It’s produced using insect cells…not eggs. Their H5N1 and tri-valent vaccines are tested and found safe. The Swine-flu vaccine is now being tested by the NIH and results should be out very soon. They are producing the vaccine at the rate of 100,000 doses per week in their limited size plant with plans for expansion. Novavax is partnered with GE Healthcare and will have plants in Spain (with NOVI) and India (with Cadila).

  2. #2 River
    July 20, 2009

    Revere,

    With so many questions still in the air about A/H1N1 vaccines, what do you think of the government extending legal immunity to the five vaccine producers should their product cause nasty side effects such as Guillian-Barre and a host of others? (AP report, 7-17-09: http://www.google.com/hostednews/ap/article/ALeqM5hjdCHrP82YTFser5vD6CzTK1az6wD99GH8580)

    Good intentions aside, the potential saving grace of the pandemic is starting to sound as frightening as the disease.

    PS. Thanks so much for once again lauding excellent reporting! The news industry may be going to hell in a hand basket, but there are still some excellent reporters in the mix.

  3. #3 revere
    July 20, 2009

    Richard: These preps are not licensed yet nor have they been tested for safety and efficacy, So while there are ways around it, most of the vaccines will be egg based until we can sort some of this out and other kinds of vaccines become available.

    River: I think there is already immunity for pandemic vaccines under recent legislation. But the race is on to check out their safety and efficacy, which still needs to be done as well as possible. Even relatively rare adverse effects, say one in ten thousand, when multiplied over millions would produce large numbers of problems and could scuttle a vaccination program if for no other reason than people would be afraid to get vaccinated.

  4. #4 raven
    July 20, 2009

    In Canada, plans are underway to try to test whether people with egg allergies could be given flu shots containing vaccine produced in eggs. Currently that is considered unsafe and is not done.

    WSJ.com

    Baxter received a sample of the flu strain from the WHO in May. The company has a cell-based vaccine technology that it says may allow for faster production and delivery than the traditional production methods that rely on chicken eggs. Novartis also made its batch with cell-based technology.

    Other companies including GlaxoSmithKline Plc (GSK), Sanofi-Aventis (SNY) and Solvay SA (SOLB.BT) have also said they have received orders for or are ready to begin producing vaccines for swine flu.

    European regulators have already cleared a mock-up pandemic vaccine made by Baxter. That clearance allows for fast-track approval of a vaccine for the specific A/H1N1 strain, the company said.

    Not quite sure why the Canadians are worrying about egg allergies and egg based vaccines. Two companies have cell based flu vaccines. The advantages are said to be twice as fast and much easier to scale up for capacity mass production.

    Also not sure about approvals. I know Baxter was making H5N1 bird flu vaccine in quanity under contract. The article excerpted above indicates they have European approval. IIRC, they also sold some to New Zealand.

  5. #5 floormaster squeeze
    July 20, 2009

    I would just like to say that egg allergy issue is a real one for me as I have a daughter who has now been officially tested as “sensitive” to egg white (no sensitivity to yolk). I was planning on getting flu shots for my daughter but I had not thought about the egg issue. The information above is appreciated.

  6. #6 chris
    July 20, 2009

    If the world is going to be short of vaccine… then surely the way to make the best use of what limted supplies we have is to test people for prior exposure to the virus before it is given.

    If individuals have already been exposed then surely it is a waste of a vaccine shot to innoculate against something they have already been exposed to. Is it possible/practicable to test in this way (either at the time the vaccine is administered or when they first fall ill) ?

    Chris

  7. #7 revere
    July 20, 2009

    chris: No, a quick test isn’t possible. It’s expensive and not that certain. If someone falls ill, there’s no reason to vaccinate them. If someone has had the flu, though, it wouldn’t make sense to vaccinate them and they could be eliminated. By the time there is any vaccine, an awful lot of people will probably have had the flu already and know it.

  8. #8 melbren
    July 20, 2009

    Along those same lines… are we tracking the people who have had laboratory-confirmed positive swine flu tests to see how many of them get sick with swine flu again? It seems to me that such information would be easily obtained and quite valuable for future outbreaks.Furthermore, could a second bout of influenza in the “first wave” population of flu-sufferers be recognized as a “canary in the coal mine” for what might signal a significant mutation or re-assortment?

  9. #9 Matt
    July 21, 2009

    What your thoughts on DNA based vaccines; such as the one being developed by VICAL? Will they be ready for primetime? They solve the egg problem and appear to able to be made in mass quantities? Seems like the government should be spending some money on these. What about needless injection options like those demonstrated by BIOJECT? Their close, again seems like we should be looking strongly at this if we got millions to vaccinate. Why so mum…

  10. #10 revere
    July 21, 2009

    Matt: We’ve done quite a few posts on alternative vaccine technologies but the bottom line is that none are far enough along in terms of testing for safety and efficacy to make it for the fall. FDA might waive some requirements in an emergency but everyone getting it would be taking a chance (of adverse effects or more likely, no beneficial effect). The risk-risk trade-off might be worth it if things indicated but at the moment most of these technologies aren’t ready in time. I’m guessing that within two years we’ll see seasonal vaccines made by one or more of these methods but I doubt it will happen for the pandemic vaccine. Could happen, though. Events sometimes have a way of taking over.