How safe is the H1N1 vaccine? November 17, 2009

Today a friend of mine shared with me an article he had published this morning about students at a local university receiving free swine flu vaccinations.

As I was reading the article, I decided the topic of H1N1 would make for an interesting blog post.

While doing a little research of my own, I was confronted with the question of just how safe the new H1N1 vaccine really is.

As a result, I have written my own article in response to the first. Here goes.

 

How safe is the H1N1 vaccine?

Despite its novelty and quick release into the market, the H1N1 vaccine is just as safe as any other flu shot.

No serious adverse effects have yet occurred during the more than 3,600 clinical trials of the vaccine, according to a letter issued November 10, by FDA Commissioner Dr. Margaret A. Hamburg to national healthcare professionals.

“We are not cutting any corners,” Hamburg said.  “Just as for seasonal influenza vaccine, no lot of the 2009 H1N1 vaccine can be used until it has been carefully evaluated and released as sterile and potent by both the manufacturer and by the FDA.”

Developers of the 2009 H1N1 vaccine follow the same procedure that is used to create seasonal influenza vaccines each year. And the same factories that are licensed to produce seasonal vaccines use the same equipment to manufacture the 2009 H1N1 vaccine, Hamburg said. 

Scientists begin by modifying the virus in laboratories until they achieve a weakened strain of it. The weakened virus is then injected into specially produced chicken eggs, she explained.

Next, the virus is allowed to multiply within the eggs until they are inoculated and a large amount of the inactivated virus can be harvested. The harvested virus is then used to produce an injectable vaccine.

“It is the efficiency of this growth that determines how much vaccine can be produced and how quickly,” she said.

The process, which is used annually to combat new strains of influenza, was approved in July 2009 by the FDA’s expert vaccine advisory committee for specific use with the H1N1 strain. And on September 15, the FDA licensed four vaccines against the 2009 H1N1 virus.

“Had this new virus emerged a few months earlier, it could have been included as one of the three strains in the 2009 seasonal vaccine,” Hamburg said.

“In this key respect, although the strain of the 2009 H1N1 virus is new, the 2009 H1N1 influenza vaccines are not.”

According to Hamburg, the testing procedures for the 2009 vaccine are nothing novel either. They are identical to the testing used for previous influenza vaccines.

First, scientists from the United States, United Kingdom, Australia, Japan and other nations collaborated as part of the World Health Organization to develop the correct proportions of antigen per dose of the vaccine.

Then, vaccine manufacturers and the National Institutes of Health began clinical trials to determine proper dosage, she said.

Although no serious adverse effects have yet been reported as a result of the 2009 H1N1 vaccine, Hamburg said that the FDA continues to watch for any unexpected, rare or serious events that may occur in connection with it.

“Should any safety concerns arise, we will evaluate them thoroughly and bring them to the public’s attention quickly,” she said.

Regardless of any uncertainties that may still exist with the new vaccine, Hamburg strongly recommends that anyone at high risk of influenza infection be inoculated.

“It is likely that most families in the United States will be touched by H1N1 influenza this year,” she said. “The benefits of preventing serious consequences from infection with the 2009 H1N1 influenza virus far outweigh the risks associated with vaccination.” 
 

To view Hamburg’s original letter, visit the following link.