If you have been postponing your flu shot until the season really gets going, do not wait any longer. It's already here, and it looks like it's going to be weird. Influenza viruses circulate quietly throughout the year in the US However, every winter increases in size, which triggers a seasonal epidemic of inhalations, sweats and sore throats. And this year has arrived earlier than usual, just in time for a potential peak during the holidays.
Normally, infections begin to increase at the beginning of January, peaking in February and then falling at the end of March. But according to data released by the Centers for Disease Control and Prevention on Friday, the flu is already widespread in 12 states, including California and New York. "We see that the activity of the flu increases around us," says Brendan Flannery, an epidemiologist with the CDC's influenza division. "The pickup in fact seems to be here."
No one guesses why the peak is ahead of the schedule. Influenza viruses are wildly unpredictable, and so far nothing – not weather patterns or demographic changes or social media data – has explained what drives an early vs. a late season.
It's not that the scientists have not tried. During the past five years, the CDC has organized a flu forecasting challenge, asking universities, companies and independent laboratories to present their best predictions about the spread of viruses. At the end of each season, the agency evaluates each model; this year there are 35. And right now they are pretty divided. Approximately half think that the peak will arrive the last week of the year, the rest predicts maximum infection rates in January and February.
Matt Biggerstaff, another epidemiologist in the CDC's influenza division, says they'll have to wait until July when I have all the surveillance data for the season to see how well each one performed. But, in general, he says that most of them can be quite accurate for short-term predictions: a week or two. Something beyond that and the signs begin to fall. That's because there are simply not too many data for the models, many of which are based on machine learning, to learn.
"We only go back to the 90s for some of these systems," says Biggerstaff. "It's not like the weather forecast, where you have stations that collect measurements in real time from thousands of places across the country, we just do not have that kind of resolution." But they are trying to get there. This will be the first year that CDC will provide state level data to modelers. Previously they were only as detailed as the 10 reporting regions defined by the Department of Health and Human Services.
But even more data would be better, for example at the county or city level – says Roni Rosenfeld, a computer scientist at Carnegie Mellon University who runs one of the modeling groups that has submitted projects to the CDC. His team's systems occupied the top two positions in last year's challenge. "The flu can cross the world in a matter of weeks, but its dynamics are very local," says Rosenfeld. "And we just do not have data good enough for local conditions."
To compensate for this, Rosenfeld's group has searched for additional sources throughout the web. Combining data from digital surveillance of flu search queries in Google, visits to CDC pages and even tweets with sound from the conventional CDC surveillance system, they trained an automatic learning model to look ahead and make predictions about future activity of the flu. "The CDC forecasting initiative has done so much to boost this field in a short period of time," says Rosenfeld. "It's been less than a decade since someone thought this was even a possibility."
Biggerstaff and Flannery hope that with more time and more research they can project one or two months into the future. That would really allow hospitals to get ahead of the increase in order to increase their staff and provide some urgency to public health officials who are driving vaccination campaigns on the ground. "Now that only happens after we've seen the first signs through the surveillance data," says Biggerstaff. In other words, a group of people had to get sick to start seeing terrifying headlines and get calls from your doctor's office. In a world where the forecast worked, he could have been receiving that news before all his co-workers began to fall like flies. "If we could move that timeline a few more weeks, we could treat a lot more people right at the start of flu activity instead of waiting for it to spread and intensify."
It would have been useful this year. With the peak potentially dropping during the holidays, many doctors' offices, outpatient clinics and hospitals will be running skeletal crews, even when the worst is about to hit. Medical researchers have expressed concern about the effectiveness of this year's influenza vaccine against the most serious strain: H3N2. Because flu mutates so rapidly in so many different strains, the vaccine every year is unique, designed to target only the strains that are most likely to cause the most damage next season. According to the CDC data, H3N2 is currently the most prominent strain that exists, responsible for 90 percent of infections since October. And it is the most likely to send children and the elderly to the hospital.
The same strain also predominated in Australia, which experienced record influenza rates last season. Below, the vaccine was only 10 percent effective against H3N2, and the composition of the vaccine, which protects against three other types of flu in addition to H3N2, is the same as that used in the US. UU For now, it's the best there is, and considering how many tricks the influenza virus has got into its lipid envelope, it's remarkable that scientists have created one that works at all. Most years, the vaccine reduces the chance of getting the flu in half; the odds have stalled at parity for decades.
But that has not stopped researchers from pursuing something even bigger: a vaccine that can combat all types of the virus. And now they are closer than ever. In October, scientists in the United Kingdom began enrolling 2,000 adult patients for a two-year clinical trial to test a universal vaccine, the first time such treatment has progressed beyond the phase one trial. The vaccine, developed by the University of Oxford and a spin-out biotechnology company called Vaccitech, will recruit 500 British subjects this season, and the rest during the 2018/19 season. If works, it would be the type of shot that would only need every few years.
Until that happens, you may want to knock out that little annoying pinch before you go home. Just make sure you call first. You will not be the only one who wants it.