The New England Journal of Medicine (NEJM) is carrying an article this week on the Chinese success in creating a serum from a bird flu survivor to treat someone with an active infection. The article requires a full subscription to the NEJM in order to access it, but WebMD has a pretty good synopsis.
First the article, then a little more background, and some discussion.
Blood Plasma From Bird Flu Survivors May Help Other Bird Flu Patients
By Miranda Hitti
WebMD Medical News
Reviewed by Louise Chang, MD
Oct. 3, 2007 -- Chinese doctors may have found a new approach for treating bird flu: Give bird flu patients plasma from bird flu survivors.
Antibodies in the bird flu survivors' plasma might help bird flu patients recover, the doctors report.
At least, that's what happened when they tried that technique on a Chinese bird flu patient.
The doctors -- who included Boping Zhou, MD, PhD, of the Shenzhen Donghu Hospital in Shenzhen, China -- describe that case in The New England Journal of Medicine.
The bird flu patient was a 31-year-old man who came to a Shenzhen clinic in June 2006 with a high fever, chills, and a cough. He had bird flu (also called avian influenza).
The doctors gave the man the flu drug Tamiflu. But the man still needed more help.
Zhou's team gave the bird flu patient three plasma transfusions from an unrelated Chinese person who had recovered from bird flu a few months earlier.
Plasma is the liquid part of blood. It contains antibodies, which fight infection.
After receiving the plasma transfusions, the bird flu patient had higher levels of antibodies that fight the H5N1 bird flu virus. He recovered and was released from hospital in early August 2006.
The bird flu patient and the bird flu survivor had had H5N1 bird flu viruses that were genetically very similar.
The results suggest that the plasma transfusion technique "may be a viable option" for bird flu treatment, Zhou and colleagues conclude.
Admittedly, this sounds promising.
Harvesting serum antibodies from someone who has been vaccinated, or who has contracted a disease and recovered, is not a new idea. Recently Chinese scientists have suggested infecting horses with an attenuated (weakened) H5N1 and producing a serum.
The process is relatively simple. Once someone (or an animal) is able to produce antibodies, a quantity of blood can be removed and through a process called plasmapheresis, the blood cells are removed from the blood plasma. This is done by passing the blood through a special filter, or by using a centrifuge. The blood plasma will contain antibodies that could then be injected into people.
A serum could, theoretically, be used as either a treatment for someone already infected, or as a prophylactic, to prevent infection.
There are problems involved, however. It takes a large amount of blood product to produce a small amount of serum. Human donors would have to be screened for AIDS and Hepatitis, among other blood borne diseases. Horse serum is still used today, although sparingly, because of `serum sickness’, a reaction to the serum that can be fatal.
And lastly, a serum is not a vaccine. It confers a temporary immunity, not a permanent one. The effects of a serum would last a few weeks, and then another injection would be needed. With each new injection, the likelihood of a bad reaction increases.
While a serum might be produced and even used, it is unlikely to be available in any quantity, and it will have a substantial potential for side effects.
In March of 2007, Chinese scientists tried again to use human serum to treat a bird flu patient, as reported by People's Daily Online.
The farmer from East China's Anhui Province, who contracted the deadly H5N1 strain of bird flu last December but was later cured of the avian disease, was called in to donate his serum for treatment of another rural Chinese woman who was confirmed last month to have been infected of the same virus.
Xu Longshan, spokesman and chief of the Fujian Provincial Professional Panel for Prevention and Control of Human Infection of bird flu, told Xinhua Saturday health workers from Anhui Province Thursday escorted the farmer, identified by his surname as Li, to Fuzhou, capital of Fujian Province, where experts from the blood center affiliated to the Fujian Provincial Bureau of Health got serum from him the second day.
Li has returned back home.
"The serum was brought to Jian'ou on the same day, and so far, medical workers have carried out the first round of injection on the woman who was just confirmed of being infected of the lethal strain of the avian disease," said Xu.
"The method is new but is for sure to be of some effect in improving the woman's capability of fighting against new rounds of infection," said Xu, who admitted it would take some time before the woman could develop immunity of her own against the avian disease.
While this experimental treatment was announced with much fanfare, follow up reporting on this patient was virtually non-existent. I saw one report that led me to believe this patient eventually died, but it did not reference her by name, making it difficult to know for sure.
While the use of human serum may have some limited applications in the treatment of H5N1 victims, it is hard to envision it becoming a panacea for a pandemic.