High dose flu vaccine contains 4 times the amount of antigen (killed flu virus) than the standard vaccine. People with the highest risk for death from influenza are infants, pregnant women and adults over 65. The high dose flu vaccine is recommended as an option in the latter group. People over age 65 have immune systems that are also aged and by giving them a higher dose there is a better chance of stimulating a good immune response. In fact, research showed a 24% improvement in immune protection.
The tradeoff for some people is a greater likelihood of local reaction or systemic “achiness” after the higher dose. For those individuals leery of these side effects the CDC proposes as another option receiving two of the regular dose vaccines a couple of months apart. However, the second dose is not covered by Medicare or commercial insurance plans.
Remember the word “recombinant” as it relates to flu vaccines for those over 50 years old.
The definition of the term is a little “medical,” but progress in the research for a better flu vaccine to protect that age group is definitely worth cheering on. The current flu vaccine confers only 36% to 80% protection.
This new DNA technology, as recently reported in The New England Journal of Medicine, was successfully used by the researchers to vaccinate with only the viral marker protein, instead of the whole virus. The patients receiving the “recombinant” vaccine had better antibody response – and fewer cases of influenza – than the patients receiving the standard vaccine.
Flu vaccines currently are produced by growing the virus in eggs, inactivating it and using it to vaccinate. Recombinant DNA technology involves inserting the DNA encoding only for the viral marker protein into a bacterial cell and allowing the bacteria to produce the marker. This gets purified and used to vaccinate.
Recent research done at St. Jude Children’s Research Hospital in Memphis led to an unusual discovery!
Rapamycin, a drug normally used to suppress the immune system was found to bolster the powers of the flu vaccine.
Rapamycin was originally discovered in a soil sample taken on Easter Island (whose Polynesian name is Rapanui; hence, “rapamycin).” Early on it was found to have antifungal properties, but additional research revealed it to also have immunosuppressant and anti-tumor properties. Giving low doses to healthy mice, it actually increases their life span.
Its main use in humans is to prevent kidney transplant rejection. Taken in small amounts with the flu vaccine, it allows the immune cells in experimental animals to make high-level and broad-spectrum antibodies.
If human results prove similar, we may all end up taking a small amount of Rapamycin prior to our then once-every-10-years flu shot.
Dear Dr.: I heard there might be a new flu vaccine that is egg-free.
You’re right. In fact you’re double right as there are two egg-free flu vaccines soon to be available.
The first one is called Flucelvax, produced by Novartis. Canine kidney cells culture is used to grow the virus instead of chicken eggs. Tested in 11,000 patients, this new vaccine was 84 percent effective in preventing influenza.
The second is Flublok, offered by Protein Sciences. This one is produced by taking the gene that encodes for hemagluttinin antigen and injecting it into baculovirus – a virus found in insects – which then produces large amounts of hemagluttinin antigen. (Remember, flu virus has two main targets for vaccination: hemagluttinin and neuraminidase.)
Tested in 4,600 patients, this vaccine was 75 percent effective. Both vaccines are currently recommended only for persons 18 years old or older.