Because it takes a lot of eggs to make the influenza vaccine each year, I wonder if this is a feasible solution for the epidemic:
At the beginning of any flu season, identify the first individual who recovers from that year’s virus infection, take blood sample and isolate individual B-cells into several sets of 96-well plates. Extract RNA from these cells and prepare recombinant antibodies and screen the ones that react with the virus. Once identified, we will have an unlimited supply of “monoclonal” antibodies that can be used for passive transfer to highly susceptible individuals. While the idea may be labor intensive, there are probably companies that are already spending huge sums of money to address the possible epidemic.
Along these lines, I saw a recent paper in which they obtained human monoclonals from a vaccinated individual.
http://www.ncbi.nlm.nih.gov/pubmed/20096915
This is an interesting idea. So, readers, what do you think of raviM7630's suggestion? Cost, practicality, possible risks, duration of action, all need to be considered, compared to conventional vaccine treatment.
ReplyDeleteI can see a couple of potential problems with this idea. First, an effective identification method needs to be established for the person who recovers from the flu first. Many people meet with their family physicians when they have less-severe symptoms such as a cold or the flu, and some never even see medical personnel if the symptoms are mild enough. Unless a nationwide communication network is established or an incentive is given, these first individuals would never be identified. Second, even if identification were possible, will they be willing to have their blood sample taken to be “manipulated” and distributed to other members of the public? The general population might find that to be a privacy/security issue and object to it. Lastly, if complications occur as a result of the vaccine, is the blood donor in any way responsible? Obviously because we are dealing with human subjects, the whole ethics and morality problem comes into play. If cost and human sampling were not an issue, this may be where the vaccination program is headed in the future.
ReplyDeleteThis is a really interesting concern, but I have to agree that the general public is likely not well-informed enough for this to be feasible. The individual who recovers first may have such good immune responses to the particular strain of flu that he or she doesn't even recognize that they have the flu, especially if symptoms only last a few days. Also, when you consider how many people are hesitant to get vaccines, I can only imagine how many people would be terrified of the thought of receiving treatment using something extracted from another person's blood. While the concept makes sense and would be very useful, I think a greater level of background education in immunology would be necessary for most people to appreciate it.
ReplyDeleteWhile the idea of extracting someone’s B-cells and replicating them for protection of others is a wonderful idea there are risks that many may not see who have not had an immune education. Each of us is different; our immune system is very smart in determining what is us and what is not and while the possibility of our body attacking the antibodies is a potential risk I also see many others. What would happen if the person who we removed the B-cells from to replicate these antibodies also had other immune problems or reactions? Their antibodies might be over active or under active. Another problem that can occur is that the flu for the most part is the same type or strain, but what would happen if this first person had used partially some medicine and did not beat the virus, thus the virus might now have turned into a new strain and this might not be as effective against the virus most of the country gets, or even the opposite could occur. The person who is the donor might have the original strain but most people are getting a mutated version of the flu. I personally don’t think we would ever find the “first” person of the flu season and be able to make a vaccine for everyone.
ReplyDeleteThis is a very sophisticated idea. Flu is a public health problem that affects millions of people, over a period of a few weeks every year. We need inexpensive, simple solutions. After the first case occurred, there probably would not be enough time to create the monoclonal Ab before the epidemic ran its course, and there would not be enough resources to make it available to many people.
ReplyDeleteGoing along the line of the post by maryb7630, the CDC website says that the flu shot is a killed virus or sometimes weakened live viruses. They also say that the prep time to make enough vaccine takes at least 6 months. Given that it takes this long just to grow enough virus (which seems like it would be quicker), the time to create an Ab from the time of first infection may be expansive. Although it may not require quite as much of the Ab to achieve the goal, the time may just be too much.
ReplyDeletehttp://www.cdc.gov/flu/professionals/vaccination/virusqa.htm
Great post! I agree with the masses in that pinpointing the "first" person infected would be like finding a needle in a haystack. If ,hypothetically,this was made available as an alternative to the flu vaccine would virus mutation be a concern??
ReplyDeleteSo I think a key question to consider may be: What is the duration of effect (half-life) of treatment with an antibody (passive immunization) compared to that with a vaccine (active immunization)?
ReplyDeleteThe challenge with Anti-body derived immunization (passive immunization) is that it lasts for only a short period of time. There is also a potential risk for hypersensitivity reactions, and serum sickness, especially from gamma globulin of non-human origin. (Since influenza is a cross-over virus, there is potential here). Passive immunity provides immediate protection, but the body does not develop memory, therefore the patient is at risk of being infected by the same pathogen later. So while antibodies to, say H1N1, may save you this season, when another breakout occurs you are left vulnerable. Is the labor intensity and cost worth the payoff?
ReplyDeleteThis would be cool, but prohibitively expensive and complicated. Wouldn't it be more effective to obtain the antibody itself from already immunized people or previously infected people for the treatment of those currently infected and faring poorly?
ReplyDeleteThe other issue with H1N1 is that the statistics widely available from the 2009 season are somewhat suspect and the media-induced panic, as always, seems to be worse than the reality. The fact is, any influenza can be deadly and still accounts for a large portion of deaths in the elderly. Influenza is the leading cause of death by direct infection in the elderly.
The take home message is, get your flu shot! They are widely available this year and immunize against H1N1. If everybody gets it, maybe the elderly and immunodeficient can rest a little easier.
The big question here (which Dr. Cohen Sr. brought up above)...is: How long would a person be protected when given passive immunity? (Can you think of other diseases where we give antibodies to patients? How often do we need to do this).
ReplyDeletePassive immunity can last from weeks to months*. Antibody vaccines like the tetanus vaccine require boosters every 10 years. This is only after receiving a series of 5 doses as a child at 2,4,6 months, around 1 year, and at 4-6 years. However, if you have not had the vaccine before, the CDC recommends a series of 3 dosages**. Other antibody vaccines, for example rabies Ig, are used after being infected.
ReplyDeleteIt seems that an antibody vaccine would require more vaccine available since people would need to return throughout the flu season. More vaccine would need to be produced to keep up with the fact that passive immunity fades rather rapidly. Of course, this is assuming that the influenza antibody titer would decrease on the order of weeks. As long as the scientists predict the influenza strains correctly for the year, the attenuated vaccine should provide a longer lasting immunity.
*Baxter, David. "Active and passive immunity, vaccine types, excipients and licensing." Occupational Medicine. 2007;57:552–556
** CDC. http://www.cdc.gov/vaccines/vpd-vac/tetanus/in-short-both.htm#who