New Vaccine May Be Most Promising Yet Against Bird Flu

August 28, 2008 02:00 PM
by Cara McDonough
Novavax, Inc. has conducted its first human safety trials with a vaccine that appears to protect against the H5N1 avian influenza strain.

A New Method

The vaccine uses a mock version of the virus, the biotech company said, and is safe enough to continuing testing on humans.

These results are strong and very competitive and they compare well with any vaccine against pandemic flu, whether licensed or in development,” Novavax President and Chief Executive Officer Dr. Rahul Singhvi said, as quoted in Reuters.

Most vaccines used weakened or killed viruses, which requires a complicated process of reformulating the strain each year using chicken eggs. The fact that Novavax’s virus uses a mock version of avian flu means their vaccine may be quicker to produce, and more effective than those developed in the past.

In the trial, 160 participants received two injections of the vaccine of varying doses, one month apart. Of those who received the highest doses, 94 percent developed immunity to H5N1, which is an Indonesian strain of the bird flu that emerged in 2005, reports The Washington Post.

There are several other biotechnology companies, including GlaxoSmithKline, Sanofi-Aventis and Novartis, currently working on bird flu vaccines under government contract.

Promising results do not guarantee a government contract for Novavax, however, said financial analyst Ken Trbovich to Bloomberg. He said that most contracts awarded in recent years have gone to “large, established players in the vaccine field.”

Bird flu rarely infects humans
, but has killed 245 out of 385 people infected since 2003, and scientists believe it could mutate into a more infectious form, according to Reuters.

Background: The first bird flu vaccine

The first avian flu vaccine, made by French company Sanofi-Aventis, was approved in April 2007 for stockpiling by the U.S. government in the case of an influenza pandemic.

But the vaccine had its faults and was only approved as “an interim measure in case an influenza pandemic strikes before a better immunisation comes along,” reported New Scientist. Two injections given 28 days apart proved to provide limited protection against avian flu. Roughly 45 percent of people given the vaccine developed an immune response to the virus.

Norman Baylor, director of the FDA’s Office of Vaccines Research and Review, said at the time that, ideally, a more highly effective vaccine would be preferable, but that “we feel as part of pandemic preparedness it would be best to have a licensed vaccine.”

Related Topic: Pandemic preparedness

In May, a report in American College of Chest Physicians’ journal, Chest, recommended which groups of people not to treat in the case of a pandemic, such as people over 85, those with mental impairment such as advanced Alzheimer’s disease, and people with severe chronic diseases.

Concern over a global pandemic has risen due to the H5N1 virus. Even though it is not yet easily transmissible to humans, some worry the virus could mutate and become highly contagious.

In January, The New York Times reported on the threat of avian flu becoming a pandemic. The flu has not become “less lethal or widespread in birds,” and experts continue to say that preparing for a major human outbreak is important, even if the H5N1 has not yet proved capable of mutating into a pandemic strain.

Dr. David Nabarro, the senior United Nations coordinator for human and avian flu, said to the newspaper that he feels less worried about avian flu than he did years ago, “not because I think the threat has changed,” but because the world is more prepared with countries, cities and schools writing pandemic plans, and vaccines being developed.

Reference: Avian flu


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