New info on current flu shows it's resistant to Tamiflu

The flu season might have to get along without the Tamiflu vaccines, this year. Fortunately, other drugs work, but the development of the resistance is interesting immunologists. Apparently the popularity of Tamiflu is one of the problems.

This is an illustration of the global nature of disease. It’s believed that the use of Tamiflu to treat upper respiratory diseases around the world has created the resistant flu strain. As Paul Bright's DJ article in December last year pointed out, nobody was sure how the new resistance would operate. Now, some rather scary information has explained that for us. The Washington Post

There were reports last year from Europe and other countries that a certain type of flu -- H1N1 -- was resistant to oseltamivir, (the technical name of Tamiflu) according to Dr. Joseph Bresee, chief of flu prevention at the U.S. Centers for Disease Control and Prevention.

This year, the CDC was on the lookout for flu resistance to Tamiflu in the United States and, sure enough, it showed up. Moreover, the proportion of the strain that is resistant has gone up from around 10 percent last year to all of the H1N1 strains this year, Bresee said.

The change in percentage is significant. The new form has taken over the strain population. This would be like a new species of cockroach replacing all other species in a year. Viral ecology is very different from the bacterial version, and this is an indicator of the (excuse the term) virulence of viral adaption. We’re talking about a continent-sized population here. Just to simplify the job of immunization, strains of flu also vary over the flu season, with different strains taking over the job of making life a misery as the season progresses. The problem is that strains create new strains, as the viral cycle of development reacts to its environment and treatments. Added to which, treatments of known strains, obviously, may not be adequate against the emerging strains. Interestingly, no resistance to Relenza, the other big name in the anti flu arsenal, has developed. That may be a result of overuse of Tamiflu in previous seasons, or a quirk in the normal resistance creation machinery where the drug was used properly, and the flu’s over adaption to Tamiflu was no use against alternative treatments. (Well, it was bound to make a mistake, sometime.) Flu remains a menace. 36,000 people die in the US every year, usually older people or infants with other medical conditions like asthma or heart disease, where the added strain of flu is fatal.