Government health officials predicted a harsher and earlier flu season this year, and so far, the forecast appears to be coming true.
Physicians in the Boston area have already reported record numbers of patients coming in with flu-like symptoms such as body aches, cough, fever, and excessive fatigue. As of late December, nearly 4,000 state residents had laboratory-confirmed cases of the flu — most had the more severe type A strain — compared with barely more than 100 confirmed cases at the same time last year.
But if you haven’t been sick yet, and haven’t gotten around to getting an annual flu vaccine, it’s not too late, said Dr. Alfred DeMaria, an infectious disease specialist at the Massachusetts Department of Public Health, since the season probably won’t peak for another month or so.
But a flu shot is no guarantee of protection. And, recently, questions have been raised about the effectiveness of popular drugs in treating the illness. Thus, despite your best efforts, you could still come down with the flu this season, leaving you out of commission for a week or more. The latest research dispels common myths about influenza, and offers a reality check on what we should expect in preventing the flu and lessening its impact.
Without a doubt, getting a yearly flu vaccine is the best preventive step you can take — and this year’s vaccine is well matched against the circulating strains — but plenty of people who get vaccinated wind up getting infected with the virus later on.
A 160-page University of Minnesota analysis of the flu vaccine published last October concluded that the yearly immunization is, at best, about 60 percent effective in children and young healthy adults and may not be very effective at all in elderly people who are most at risk of dying from flu-related complications.
“Public health officials have sent out the message that the flu vaccine works about as effectively as other vaccines, about 70 to 90 percent of the time, but I would say that’s been overestimated,” said Michael Osterholm, an epidemiologist at the University of Minnesota’s Center for Infectious Disease Research and Policy who led the team that issued the flu vaccine report. “But some protection is better than nothing, so it’s still a good idea to get the vaccine. I just don’t think we should be overselling its benefits.”
The report called for more investment into experimental flu vaccines that would provide stronger protection against multiple influenza strains and last for up to a decade.
The government’s Advisory Committee on Immunization Practices began recommending in 2010 that everyone age 6 months or older get a yearly flu vaccine, but it’s not yet clear how much of an impact that has had on preventing the estimated 3,000 to 49,000 deaths that occur every year in the United States from the flu. Population studies indicate that people who get an annual flu vaccination have about a 4 percent lower risk of dying from the flu compared with those who don’t get annual vaccinations, according to Osterholm.
He and his colleagues’ analysis of 31 studies examining the flu vaccine’s effectiveness — excluding hundreds of studies that didn’t use adequate lab testing to confirm flu infections — concluded that “evidence for consistent high-level protection is elusive for the present generation of vaccines.” For those more likely to have life-threatening complications from the flu because they are older than 65, or have an impaired immune system or a lung condition such as asthma, that’s especially true.
But not everyone agrees with these conclusions. DeMaria pointed out that Osterholm’s team excluded important papers such as a 2004 Dutch study, which found that elderly people who had annual flu shots were less likely to die of any cause during the flu season than those who didn’t get vaccinated.
And Japan saw a temporary sharp decline in elderly flu deaths after the country began requiring yearly flu immunizations for all children in public schools — a policy that has been revoked because of logistical problems.
About two-thirds of children in Massachusetts get a yearly flu vaccination, which probably helps prevent some spread to seniors — though not as much as if children were required to be vaccinated for school entry. DeMaria said there are no plans for such a policy.
Parents may want to consider for their children the nasal spray form of the vaccine, which has a live attenuated virus, since it appears to work more effectively in young children ages 2 to 9, compared with the shot. For older children and adults, the needle jab appears to be more effective than the nasal spray. A higher-dose flu vaccine shot approved for those age 65 and over could “lead to greater protection against the flu” among this population, according to the federal Centers for Disease Control and Prevention’s website.
Regardless of the type of vaccine administered, “it’s probable that the older you are, the less likely you are to have a robust response to vaccination,” DeMaria said.
Beyond immunizations, washing hands frequently with soap and water, keeping your hands away from your eyes, nose and mouth, and avoiding close contact with sick people can also help prevent flu infections, according to the CDC.
Getting an accurate accounting of how many Americans develop the flu each year is nearly impossible because most people with symptoms never visit the doctor.
“It’s hard to know entirely for sure whether you have the flu or a bad cold,” said Dr. Joshua Kosowsky, vice chair and clinical director of Brigham and Women’s Hospital’s emergency department and coauthor of “When Doctors Don’t Listen.” “If you have fever, body aches, and fatigue along with a cough during flu season, it’s likely you also have the flu.”
More than 35 percent of patients in the New England region who went to see doctors with flu-like symptoms tested positive for influenza during late December, according to the CDC, and most flu patients are instructed to return home and manage their symptoms with bed rest, plenty of fluids, and ibuprofen or acetaminophen to reduce body aches and fever.
What usually leads people to seek medical attention, Kosowsky said, are severe symptoms such as chest pain — which could indicate pneumonia — shortness of breath, or dizziness due to dehydration. Some may also be looking for a prescription for an antiviral drug such as Tamiflu, which work best when given within the first day or two of symptoms appearing.
Boston resident Stephanie Allen, 40, said she was compelled to drag herself to her doctor’s office a day after Christmas after more than two days of fever, chills, vomiting, and a hacking cough. “I almost wasn’t going to go, but then a friend told me about Tamiflu,” said Allen, who hadn’t received a flu immunization and who tested positive for the flu virus. But she might not have received Tamiflu early enough to help: A week later, she was still dealing with a cough, headache, and clogged sinuses.
None of the flu strains circulating this year has shown resistance to either of the antivirals on the market — Tamiflu (oseltamivir) and Relenza (zanamivir).
They’re also 70 to 90 percent effective at preventing the flu in those who are caring for infected individuals in their household.
“The drugs shorten the course of symptoms, on average, by about a day,” said Dr. Geneve Allison, an infectious disease physician at Tufts Medical Center. “But they could shorten symptoms by up to three days if you take the drug within the first 24 hours after the onset of symptoms.” Tamiflu was approved last month for use in babies as young as 2 weeks.
Whether the antiviral drugs reduce severe flu complications that lead to hospitalizations or serious bacterial infections such as pneumonia depends on whom you ask. The US Food and Drug Administration states on its website that neither Tamiflu nor Relenza has been shown to prevent complications such as pneumonia based on clinical trial data provided to the agency from manufacturers.
The CDC, on the other hand, states on its website that “early antiviral treatment . . . may reduce the risk of complications from influenza (e.g., otitis media in young children, pneumonia, respiratory failure) and death, and shorten the duration of hospitalization.” That’s based on studying patients in hospitals who have been treated with the drug, according to Tim Uyeki, chief medical officer in the influenza division at the CDC.
Researchers have been pressing Roche, manufacturer of Tamiflu, to release its full set of clinical trial data to get a better handle on the drug’s benefits and possible psychiatric side effects such as delirium, hallucinations, and self-injury. The FDA has the full data but says it’s not required to release it to the public; the CDC doesn’t have the data.
“Eight out of the 10 trials on which Roche bases it claims for safety and effectiveness have never been published,” said Peter Doshi, a postdoctoral fellow at the Johns Hopkins University School of Medicine in Baltimore who has been leading the effort to review the Tamiflu data. “There’s a whole world of hidden data, and it’s just not acceptable.”
Roche responded in a statement that it is planning to set up an advisory board of experts from outside the pharmaceutical industry “to review the totality of Tamiflu data and agree on a statistical analysis plan. We believe this approach is a fair and transparent way of addressing this public debate.”
Deborah Kotz can be reached at dkotz@
globe.com. Follow her on Twitter @debkotz2.