Time to postpone the seasonal vaccine?

Here is an edited excerpt from a post on the ClinMicroNet, a listserve for clinical microbiologists. The author is with the Ontario Public Health Labs and has seen the Canadian data we’ve blogged about here and here.

Yes, unfortunately the study is still under review--however it is the worst kept secret in the country. Basically, data derived from a cohort of patients in a vaccine efficacy study that has been ongoing for a number of years has shown that persons under 50 that got seasonal vaccine last year were at 2X the risk of getting H1N1. Data looks very compelling and although never seen with influenza (no one has had opportunity to look) there is other viral precedents (antibody dependent enhancement). As a result Ontario (and probably most provinces will follow) will first vaccinate those >65 (and nursing home residents)---they are least susceptible to getting H1N1 but at greatest risk for H3N2—and then provide H1N1 for high risk people, and then for everyone else. Then decision will be made re rollout of seasonal vaccine, if at all.

If you take into account these admittedly preliminary (and unconfirmed) findings, the fact that over 95% of influenza A viruses being typed in the U.S. right now are H1N1, and the imminent availability of the novel H1N1 vaccine, you have a strong argument for taking the approach described above—reverse the order of vaccination, get H1N1 vaccine out first, and worry about the seasonal vaccine later…….

H1N1 vaccine: The basics

A little Q&A from the CDC, to be posted on the Emerging Infections Network listserve shortly, is posted below. See this link for more details from CDC on H1N1 vaccine safety, and in case you missed it, check out this NY Times piece that nicely outlines the challenges associated with monitoring for adverse events during this massive vaccine rollout.

Looking at the CDC's web site it looks like vaccine distribution has been pushed back to mid November; is that correct? Planners should assume shipping of vaccine will begin in early October.

What dose of antigen (15 or 30 micrograms) will be used? 15 micrograms

Will an adjuvant be utilized? No. According to current federal plans, only unadjuvanted vaccines will be used in the United States during the 2009-2010 flu season. This includes all of the 2009 H1N1 and seasonal influenza vaccines that will be available for children and adults in both the injectable and nasal spray formulations. None of these influenza vaccines will contain adjuvants.

2009 H1N1 vaccines with adjuvants are being studied to determine if they are safe and effective. Experts will review these data when they are available. There is no plan at this time to recommend a 2009 H1N1 influenza vaccine with an adjuvant.

There are 5 companies that are under contract to provide the vaccine. Are they all using the same seed virus? Yes, they all use the same master seed strains.

Uh-oh...more on the flu vaccine study from Canada

Today's Toronto Globe and Mail gives us more detail on the potential link between receiving seasonal flu vaccine and an increased risk for H1N1 infection. From the article:

Their paper (Danuta Skowronski and colleagues) found that consistency across four epidemiologic studies and one animal experiment suggested "an association that cannot be dismissed on the basis of chance and is unlikely to be explained entirely by bias." "If this association is real, these studies together suggest that recipients of seasonal [influenza vaccine] were at moderate 1.5-2-fold increased risk of medically attended H1N1 illness during the spring/summer 2009," the paper said.

Let's hope the paper is published soon. This will surely complicate vaccination campaigns.

State versus Feds

One thing I’ve been pleasantly surprised by during this H1N1 season is the willingness of some state departments of public health to issue guidance that differs from that of the CDC. I’m a little surprised that the media hasn’t paid more attention to this.

CDC says all health care workers with ILI should stay home for 7 days? Iowa says nah, come back if you’ve been afebrile for 24 hours and your cough has improved.

CDC says wear an N95 mask for all direct contact with patients with suspected H1N1? Iowa says no, surgical masks are fine except for aerosol-generating procedures.

On the one hand, this makes it easier for hospitals like ours to establish sensible, and feasible, policies during the long H1N1 season….on the other hand, neither the state public health department nor the CDC is going to come in to your hospital and slap you with a big fine. OSHA might….and they will require you to follow CDC guidance.

So maybe, one day, CDC and OSHA will get their collective “stuff” together and issue guidance that actually makes sense for busy, understaffed hospitals, and that can be sustained through future influenza seasons (since H1N1 is, after all…..an INFLUENZA virus).

Mandating flu shots for healthcare workers

Today's Washington Post has an article on hospitals, health systems and states that are mandating flu shots for healthcare workers. While I certainly support the vaccination of healthcare workers, mandating it makes me uncomfortable. What I find grossly unfair is when hospitals exempt physicians from the mandates. While in many hospitals physicians are not employees, they are credentialed by the hospital. So hospitals that believe that all healthcare workers should be vaccinated should make this a requirement of the credentialing process. Otherwise, it creates a double standard that further undermines employee buy-in.

Infection prevention: The media backlash!

A couple news articles today are designed to generate annoying e-mails to tired infection preventionists….

The first story, from CNN, is really a non-story that takes the fact that influenza is a respiratory virus (that spreads, you know, from respiratory droplets) to insinuate that hand hygiene is not an effective flu prevention measure. Numerous experts are cited, not all of them say the same thing.

The second is a bigger deal, because it appears to already be affecting vaccine policy in at least one Canadian province. Apparently some Canadian studies have linked prior receipt of seasonal flu vaccine to an increased risk for H1N1 infection. The news account is here and I wish I could link to the study data—but it isn’t published and won’t be released by the investigators until it is peer-reviewed (then why leak it to the media, is my question…..). Tom Frieden had little to say about this issue at the CDC press conference, except that data from the U.S. and Australia have not shown such an association.

Light posting this week....

Sorry about the infrequent updates this week. As many of you are no doubt doing, I’m still spending a lot of time dealing with H1N1-related issues. We already have a shortage of N95 masks, so have been working with units to educate them about re-use. H1N1 vaccine may be arriving sometime in early October, in limited quantities, so we are busy prioritizing risk groups for vaccination. We are also starting to see symptomatic healthcare workers in our employee health clinic for testing (we are testing those who meet “influenza-like illness” criteria in an effort to get those who test negative for H1N1 back to work sooner than the current CDC recommendation of 7 days). Meanwhile, our state department of public health is preparing to recommend that healthcare workers can return to work after 24 hours afebrile with improvement in other symptoms. We’ll soon be in a situation where our state department of health has substantially different recommendations than CDC for both isolation precautions (surgical vs. N95 masks) and healthcare worker sick leave. Unless the CDC issues updated guidance soon…..

Time for another reality check—pneumonia and influenza mortality remains below the epidemic threshold:

Sufficiently bored now? Then read more about MRSA everywhere, this time in our favorite animals….