By now everyone has a pretty good idea of how important the flu vaccine is. Even in a mild flu season, the vaccine saves thousands of lives and millions of dollars in healthcare costs and lost workdays. But if you’re a public health official, it isn't so easy—it takes a really long time, often months, to actually produce a vaccine.
That should change, at least for next flu season: Two new flu vaccines were recently approved that will significantly cut the lead time needed to produce a flu vaccine targeted to a specific strain. (Every season’s virus has to be created specifically to fight that year’s predicted strain or strains.)
Public health experts have been waiting for a faster way to make the flu vaccine for a long time. The painfully slow process of making flu shots became clear during the H1N1 pandemic in 2009-2010. That outbreak began in the spring of 2009, and by April the U.S. government had declared a public health emergency. By June, 18,000 cases of H1N1 had been reported.
But it took until early October before an H1N1-specific vaccine was available—and even then there was a limited supply of it.
The new shots will help health officials get vaccine to people much faster. One new product, called Flublok, was approved recently by the Food and Drug Administration (FDA) and will be available for the 2013-14 flu season for people ages 18 to 49. The other new vaccine, Flucelvax, was approved in November 2012 and is already available for people ages 18 and older. Both vaccines are unique because they are not manufactured with chicken eggs. (Chicken eggs have been used to make vaccine for seven decades; the viruses need a host cell in which to replicate, and chicken eggs are seen as the least expensive type of host.)
Traditionally, the process of making a flu vaccine begins when officials with the Global Influenza Surveillance Network determines which strains are most likely to be a problem for the upcoming flu season and orders vaccines for those strains. The actual manufacturing process is time-consuming and involves hundreds of millions of eggs. It can take up to six months—and that's if everything goes well. Manufacturing problems, such as contamination, are common.
But instead of chicken eggs, Flublok is made by infecting cultures of insect cells with a virus that turns them into hemagglutinin factories. Hemagglutinin is a protein that covers the surface of the virus. Flucelvax is made using mammalian cells. There is no risk of getting the flu from either vaccine.
"If we're suddenly afflicted with a new pandemic virus, we always struggle to create a vaccine as quickly as possible. Both of these methods, we anticipate, will curtail the time from the identification of the new pandemic virus to actually having a vaccine for use," Dr. William Schaffner, chair of the department of preventive medicine at Vanderbilt University and a spokesman for the Infectious Diseases Society of America, told TakePart.
According to the manufacturer of Flublok, the production of the vaccine was achieved 21 days after obtaining the genetic sequence of the target virus. Flublok was found to be about 44.6 percent effective against all flu strains in studies (by comparison, this year’s vaccine is estimated to be about 62 percent effective). The vaccine's safety was tested in about 2,500 volunteers, according to the FDA. The most common side effects were pain at the injection site, headache, fatigue, and muscle aches, which are also common in recipients of conventional egg-based flu vaccines.
"The immune response they create is comparable to the existing vaccine," Schaffner says. Moreover, studies indicate that Flublok may even confer protection against a broader spectrum of viruses.
Some consumers who are allergic to eggs may prefer one of the two new vaccines, when they become available next year. However, Schaffner notes, several recent studies show the current vaccine that is grown in chicken eggs is safe even for people with egg allergies.
The new vaccine-manufacturing process is part of a new era of advances in influenza prevention. Researchers, for example, are intent on developing a vaccine that provides protection for more than one year and for many different strains of flu.
"I think it's fair to say in the last six years—ever since bird flu was on the horizon—there has been more investment in researching improved influenza vaccines," Schaffner says. "Everyone is trying to work on a way to make a better vaccines."
Would you get the new egg-free vaccine during the next flu season? Did you get a flu shot this year?