Drugstores got an early jump on the flu season by offering vaccinations in late summer.
The big public immunization campaigns began last month. And there is plenty of vaccine to go around.
Manufacturers have distributed nearly 113 million doses – out of a projected 135 million doses – across the United States.
Now, it’s a matter of waiting for the flu, which is always around in very low levels, to begin increasing toward its seasonal peak as the weather turns colder.
“Don’t be fooled by the mild flu season last year,” said Dr. Gale Burstein, Erie County health commissioner.
“The Southern Hemisphere had a pretty significant flu season,” she said. “And what happens there is often an indication of what’s ahead for us in the Northern Hemisphere.”
Seasonal influenza is caused by influenza viruses that infect the nose, throat and lungs. It is believed to spread mainly from person to person in respiratory droplets of coughs and sneezes.
Symptoms can include coughs, runny noses and sore throats. And, unlike other viral respiratory infections, such as the common cold, the flu can cause serious illness, especially in the elderly, pregnant women and individuals with chronic medical conditions.
The number of deaths annually in the United States associated with the flu ranged from 3,000 to 49,000 between 1976 and 2007, according to the federal Centers for Disease Control and Prevention. During a regular flu season, about 90 percent of deaths occur in people 65 years and older.
The viruses that cause influenza constantly mutate, changing year to year, requiring manufacturers to regularly update the vaccine based on predictions of what strains will predominate. Among other things, experts study the major strains of the virus circulating in the Southern Hemisphere, which experiences winter when it is summer in the Northern Hemisphere.
As a result, flu vaccine does not guarantee total protection. Its effectiveness depends in part on the match between the viruses in the vaccine and the viruses circulating in the community. Vaccines contain inactivated viruses or, in the case of the nasal spray, weakened viruses.
This season’s vaccine has one strain in common with last year’s vaccine – the 2009 H1N1 virus – as well as two new H3N2 and B strains.
The CDC recommends that everyone 6 months and older get the flu vaccine. This recommendation represents an expansion from the past and has existed since 2010, when a federal panel of medical experts voted for universal flu vaccination in the U.S. to expand protection across the population.
The thinking goes that the more people who get vaccinated, the more people will be protected from getting sick or spreading the virus to others, thus making the chances for an outbreak slim.
This is called herd of community immunity.
Burstein also highlighted the emerging concept of “cocooning,” the idea of immunizing the close contacts of children, especially those too young to be immunized. In its vaccination recommendations published last month, the American Academy of Pediatrics urged physicians to vaccinate such close contacts, including parents and day care center workers.
“You’re creating a protective layer around susceptible people,” she said.
Four influenza vaccine options are available: a nasal spray; the traditional shot into muscle; another shot with a smaller needle placed just under the skin; and a high-dose injection for people age 65 years and older.
The Visiting Nursing Association of Western New York anticipates providing 25,000 flu vaccinations this season, which is somewhat less than in the past and a reflection of several trends.
“You’re seeing more providers offer immunizations, especially pharmacists, and health insurers have pushed doctors to do more vaccinating in their offices,” said Lisa Greisler, vice president of clinical service for the VNA.
New York State in 2008 allowed pharmacists to administer flu shots. Since then, about 8,100 pharmacists, which accounts for most of those who work in retail pharmacies, have completed training, said Craig Burridge, executive director of the Pharmacists Society of the State of New York.
As for the status of the flu, the season has been known to start as early as October and last as late as May, and generally peaks in February.
The CDC last week issued its first weekly update for 2012-13, and it showed the expected for this time of year – low flu activity.
Influenza vaccination rates have increased, particularly with the expansion of the recommendations for who should get the vaccine.
But about 42 percent of Americans 6 months and older were immunized for the 2010-11 flu season, far less than the 80 percent goal in the nation’s disease-prevention plan, Healthy People 2020, the CDC recently reported.