Manufacturing difficulties have slowed distribution of this year’s flu vaccine, annoying some pediatricians and forcing some people to wait to get the shot they want, experts say.
Blame it on the antiquated technology that is still used to make most influenza vaccines.
Flu vaccines usually start shipping to doctors, clinics and other distributors in August and peak vaccination season is typically September and October. Pediatricians, employers, retail pharmacies and others plan their vaccination campaigns around this schedule.
But this year, delivery has been held up by around six weeks, infectious disease experts and manufacturers say.
“Several companies experienced slower yields than expected,” said Dr. Andy Pavia, chief of pediatric infectious diseases for the University of Utah. “Their flu vaccine is being produced, but it’s coming out slower than anticipated. Deliveries are a little bit behind schedule but they anticipate getting most of it out by the end of October, when most was promised by mid-September.”
"Deliveries are a little bit behind schedule."
That still gives plenty of time to get vaccinated before flu season starts in December, Pavia said.
The Centers for Disease Control and Prevention says it is not worried.
“Some companies have communicated information to their customers about delays in shipments that had originally been anticipated for August and September,” CDC said in a statement posted on its website.
“Despite these early season shipping delays, however, manufacturers anticipate the majority of their flu vaccine distribution will occur by the end of October. While this is slightly later than vaccine was shipped last year, it is not an unusual pattern for seasonal flu vaccine distribution overall.”
Flu vaccine supplies depend on the private market. Vaccines are made by drug companies and they decide how much to make. But the federal government influences this by buying vaccines for use in child vaccination programs. Federal advisers also decide on the formulation.
“In our case, a portion of our flu vaccines supply has been delayed due to production difficulties that we experienced at a manufacturing facility outside of Montreal,” said Robert Perry, a spokesman for GlaxoSmithKline.
“Vaccines manufacturing is an inherently complex undertaking. When vaccines batches fail quality-assurance tests at any stage of the process, we discard them and start over. This is the primary reason for some of our vaccines being delayed, and it reflects that that patient safety trumps all else, particularly shipping considerations,” he added.
The vaccines that Glaxo makes are done the old-fashioned way, using virus injected into chicken eggs. It’s an inherently unreliable process, prone to delays. Sometimes the virus used as a seed to make the vaccines doesn’t grow well in the eggs.
Perry says Glaxo will eventually deliver 25 to 27 million doses by the end of October.
Dr. Henry Bernstein, a specialist in pediatrics at North Shore-LIJ Health System in New Hyde Park, N.Y., who writes flu vaccine policies for the American Academy of Pediatrics, says he is not unduly worried.
“We have heard it is a little bit of a hassle for some people."
“Any time there are delays, there is always some concern that some children will not get vaccinated,” Bernstein told NBC News. But he said in terms of overall numbers, the shortage wasn’t bad compared to years past. “We have heard it is a little bit of a hassle for some people,” he said. “Hopefully, it won’t last long.”
This year, the CDC expects up to 159 million flu vaccine doses to be available. As of last week, 98.9 million doses had been distributed. To compare, last year companies made about 135 million doses and by mid-October, 110 million doses were distributed.
Seven companies now make vaccines for the U.S. market – a big change over the 1990s, when just four companies did. There are also more varieties of flu vaccine available than ever before – special formulations for the elderly, for people allergic to eggs, vaccines that protect again four strains of flu instead of three, needle-free vaccine that is sprayed up the nose and vaccines delivered with a shorter needle.
And some companies have vaccines that are not made using chicken eggs. Flucelvax is made using dog cells cultured in the lab. Another is made using genetic material.
Public health experts struggle every year to get the flu vaccine supply right. Vaccine makers only want to make as much as they can sell and in 2012 the U.S. threw away 30 million doses. In 2008-2009 companies shipped 162 million doses of vaccine, but only 90 million were used.
The CDC says everyone 6 months and older should get vaccinated against flu, or about 300 million people. But last year, less than half the population did. People are not afraid of the flu, even though it kills as many as 40,000 people in a bad year, including 100 children every year. But in some years it may be a mild season and kill 4,000 people. This variation lulls people into thinking flu isn’t a problem.
The flu vaccine isn’t perfect, either, leading many to think it’s a waste of time to get one.