Until last year, the advent of the new influenza season was a pretty routine event on the health care calendar. Around October, people would be urged to receive vaccinations against the viral strains expected to plague North America in the coming months, with young children and older adults encouraged more strongly to get their annual shot. Other folks received their vaccine with all the enthusiasm of a trip to the dentist – something you know is good for you, but not exactly an urgent concern.
That all changed last year, thanks to the novel H1N1 virus, aka swine flu, aka the global flu pandemic. Suddenly, seasonal flu clinics used to a slow trickle of customers were faced with lines out the door and around the block, as the combination of limited H1N1 vaccine supply and media hysteria created unusual demand. Caught short by the late-breaking new strain, suppliers had to prepare a separate vaccine for the H1N1 virus, requiring people to get stuck with a needle twice for full protection.
The good news heading into the 2010-11 flu season is that many of those logistical headaches have been resolved. With no new strains rearing their head since last year, vaccine makers were able to consolidate protection against H1N1 and two seasonal strains into one injection or nasal spray. The Centers for Disease Control and Prevention recommendations have also been simplified: all people above the age of 6 months are advised to get the flu vaccine, full stop. All signs this season also point to better preparedness across the board from government and private organizations dispensing the vaccines – local Walgreens in Chicago were advertising vaccine availability well in mid-September.
To raise awareness of vaccine availability on the University of Chicago campus, ScienceLife talked to two of our flu experts: Stephen Weber, medical director of infection control at the Medical Center, and Ken Alexander, chief of pediatric infectious diseases. Here’s a few of their answers about this coming flu season and the research taking place one year post-epidemic.
Q: If 2010-11 is expected to be a routine flu season, what does that mean?
Weber: A regular flu season doesn’t mean that it’s easy or that people don’t get sick. We have to remember that while flu is a very common illness, folks who are not vaccinated are at an increased risk.
In many resepects we return to our usual state of flu awareness and preparedness. Bearing in mind, we are talking about infections that kill 24,000 Americans each year, and that’s not something that we want to neglect or that we want to be anything but vigilant about. We have an opportunity to save lives, and whether it happens to be a pandemic or a seasonal year, we still have an important responsibility.
Q: Why is it especially important for parents of infants to be immunized against flu?
Alexander: It’s the notion of a “cocoon.” The idea here is that babies under 6 months don’t respond well to flu vaccine, so we don’t get give shots. So you have this window of vulnerability, and babies are at high risk. With cocoon immunization, if can’t immunize the kid, we can immunize everybody around the child.
There are good data on pertussis transmission to babies, that they receive the virus one-third of the time from the mother, a quarter of the time from dad, and a quarter from their grandparents. Flu is probably pretty much the same, and the idea is we can protect them if we immunize people around the baby.
Q: For the first time, a new stronger flu vaccine is available for patients 65 and older. Why?
Alexander: There’s a concern that, just like everything else in the body, the immune system ages as well. With older adults, the combination of immune aging with other causes of morbidity, such as heart disease, diabetes and so on, all add together to diminished immunity and a greater predisposition to communication. So a more immunogenic vaccine might protect older adults better. For us in the health care setting, it’s probably not really cost-beneficial to do something like that. But this is at least something that will be considered for our patients.
Q: Did last year’s flu season change feelings about how the nasal spray vaccine (which uses live, weakened virus) can be used in a health care setting?
Weber: That’s one silver lining of last year. Historically, we were always concerned to use nasal live virus vaccine in case it put all of our patients at risk, but it was never more than superstition. Health care workers were traditionally dissuaded from that vaccine, but we had a favorable experience with it during the pandemic, so I think that barrier or taboo has been broken.
We still don’t want health care workers that work with immuno-compromised patients to use that vaccine, but for a lot of health care workers it’s a good choice. It’s especially good for the health care workers out there who are afraid of needles, which is a recognized barrier for some folks. The nasal spray knocks down that barrier.
Q: At the end of last season, some scientists expressed concern that the new H1N1 strain might mutate into a more dangerous form. Is that still cause for worry?
Alexander: There is a difference between viral shifts and drifts. What people were concerned about was an H1N1 antigenic shift, which occurs every couple of decades and is essentially a complete wardrobe change for a virus. Then you can also get drifts, point mutations that lead to small changes in the virus.
I am sure there have been small changes that have occurred since what they tested against in the vaccine clinical trial, but the vaccine strain being used in this year’s vaccine is close enough to what’s circulating to confer protection. What’s always a concern is does another drifted strain show up and sneak outside the vaccine? Essentially, by giving a flu vaccine you’re selecting against the current strain and providing positive selection for drifted strains. I don’t know if this vaccine causes that, but the good news is that any drifts that have occurred are small enough that it won’t interfere with conferring immune system protection against the wild type virus.