- The Washington Times - Wednesday, October 6, 2004

The influenza vaccine can’t give someone the flu, says Jay Barbaccia, director of the pharmacy at Washington Hospital Center in Northwest. However, influenza causes about 36,000 deaths and 200,000 hospitalizations in the United States each year.

“There are a lot of misconceptions in the public,” he says. “The influenza injection is not a live virus and cannot produce influenza. Some people get the vaccine and develop a cold, and that has nothing to do with the vaccine. … It’s an excuse that people use to not be vaccinated.”

Making the flu vaccine is a complicated process. Because it’s a new product every flu season, the creation of a vaccine must occur each year, accommodating the most prevalent types of strands of the illness. Researchers also study new ways to improve the vaccine.

Manufacturing companies planned to deliver about 100 million doses of the flu vaccine to the United States this year, says Dr. Keiji Fukuda, team leader of the epidemiology unit in the influenza branch at the Centers for Disease Control and Prevention in Atlanta, Ga.

Because of contamination, however, only about 54 million doses will be delivered from Aventis Pasteur, CDC says. MedImmune also will deliver about 1.5 million doses of the vaccine nasal spray by the end of October.

Chiron Corp., which was scheduled to deliver 46 million to 48 million doses by the end of November, destroyed eight lots of the vaccine because they did not “meet product sterility specifications,” officials say. Originally, this was only going to cause a delay in delivery.

However, as of the beginning of October, the Medicines and Healthcare products Regulatory Agency in the United Kingdom suspended Chiron’s license for three months, which prevents the company from delivering any doses during the 2004-05 season. Because Chiron didn’t release any vaccine, there will not be a recall of the product.

About 185 million people in the United States should get the vaccine, Dr. Fukuda says. Because there is a shortage of the vaccine this year, however, it should be reserved for people in the highest risk categories such as people 65 and older and those with significant chronic illnesses, according to the American Lung Association.

Manufacturers usually gauge how much vaccine to make from the demand of the previous year. With an increase in the demand for the vaccine, there would be more supply. Last year, about 87 million doses were made.

“Obviously, [manufacturers] don’t want to make so much vaccine that they throw out a lot,” he says. “Two years ago, they ended up throwing out several million doses.”

Global surveillance is conducted year-round to determine which three strands of flu virus will be part of the upcoming vaccine, says Alexander Klimov, chief of the strain surveillance section of the influenza branch at the CDC. He holds a doctorate in biology.

In both the Northern and Southern hemispheres, once a year, the vaccine strains used in the upcoming flu season are selected about eight months in advance. Those are selected by looking at data from the World Health Organization’s 110 National Influenza Centers and other laboratories in 83 countries. WHO Collaborating Reference Centers for Influenza, which are located in Atlanta, London, Tokyo and Melbourne, Australia, oversee the program.

“In Atlanta, which is also a National Influenza Center and WHO collaborating center for surveillance, epidemiology and control of influenza, we receive between 2,500 and 3,000 strains per year,” Mr. Klimov says. “Analyzing those viruses allows us to better understand whether vaccine strains have to be updated or previously selected vaccine strains still can be used.”

The Vaccines and Related Biological Products Advisory Committee (VRBPAC), which is under the Food and Drug Administration, makes the final decisions as to which vaccine strains are recommended for the United States.

The strains chosen for the vaccine must be antigenically similar, or have the same makeup, as the majority of viruses predicted to be circulating in the flu season. They also must be antigenically similar to the World Health Organization’s recommendations. Further, the strains must be isolated and maintained in eggs and be able to grow well in eggs.

According to the Centers for Disease Control and Prevention, this year’s vaccine includes A/Fujian/411/2002 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Shanghai/361/ 2002- like antigens. For the A/Fujian/ 411/2002 (H3N2)-like antigen, manufacturers can choose the equivalent A/Wyoming/3/2003 (H3N2) virus; and for the B/Shanghai/361/2002-like antigen, manufacturers can choose the equivalent B/Jilin/20/ 2003 virus or B/Jiangsu/10 /2003 virus.

“With any kind of vaccine, most people don’t understand how much work was done before it was approved,” Mr. Klimov says. “It’s much more complicated than it looks like.”

After the strains are chosen, the virus is inoculated into eggs, says Dr. William Schaffner, professor and chairman in the Department of Preventive Medicine at Vanderbilt University Medical Center in Nashville, Tenn.

“The vaccine is actually made in a very standard, but somewhat old-fashioned way,” he says. “It’s not grown in a test tube. It’s grown in eggs.”

The FDA has a foray of specially certified egg producers that have to meet special standards, Dr. Schaffner says. In general, it takes one egg per dose of vaccine.

“So if you’re making 100 million doses of vaccine, that’s a lot of eggs,” he says. “We need lots of roosters and lots of chickens, under ideal circumstances, to make a lot of eggs.”

The manufacturers harvest the viruses from the eggs and then kill the virus, Dr. Schaffner says. Then the virus is fractionated so only pieces of the virus go into the vaccine, and they are mixed with the constituents of the rest of the vaccine. All along the production, the vaccine must meet certain FDA quality-assurance standards.

Last year for the first time, MedImmune offered a live virus vaccine through a nasal spray, which is slightly different from the inoculated vaccine, Dr. Schaffner says.

People spray the live virus into their noses. It multiplies there and creates immunity. Because it’s a temperature-sensitive vaccine, it can’t create the illness, Dr. Schaffner says. It is unable to live in the chest, which is 98.6 degrees Fahrenheit, he says.

Doctors and scientists continue to study ways to develop new vaccines, says Dr. Gregory A. Poland, director of the Mayo Vaccine Research Group in Rochester, Minn. Identifying the piece of a virus or bacteria that is responsible for generating immunity in the human body is one of the main challenges.

He uses mass spectrometry to feed cultured cells a virus. Then he pulls from the cultured cells a little piece of virus that the human body sees.

“What we hope to do is after identifying that, actually make a vaccine after the little piece,” he says. “The advantage of that is you don’t have to give someone a live virus” (like the live virus smallpox vaccine).

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