New study indicates smallpox vaccination effective for decades
A study describing how cells within blood vessel walls move en masse overturns an assumption common in the age of genomics - that the proteins driving cell behavior are doing so much multitasking that it would be near impossible to group them according to a few discrete functions. But now researchers at the Stanford University
Full Post: Multitasking proteins driving cell behavior
Although naturally occurring smallpox was eradicated in 1977, there is concern that bioterrorists might obtain smallpox from a laboratory and release it into the population.
Under such circumstances, the supply of smallpox vaccine may be insufficient for universal administration. In a study published in the December 2008 issue of The American Journal of Medicine, researchers found that lifetime protection is obtained from just one vaccination, even when that vaccination occurred as much as 88 years ago. They conclude that in the event of a smallpox bioterrorist attack, vaccinia smallpox vaccine should be used first on individuals who have not been vaccinated previously.
Examining 246 participants of the Baltimore Longitudinal Study of Aging, investigators from the National Institute on Aging and the National Institute of Allergy and Infectious Diseases, National Institutes of Health found permanent immunity was conferred by vaccination or by survival from an active smallpox infection. In the sample, 209 subjects were vaccinated one or more times 13 to 88 years prior to the study; an additional 18 had had childhood smallpox, and 29 with no history of vaccination or smallpox were included.
Although the vaccinia virus vaccine was used since the late 18th century, routine vaccination was discontinued more than 30 years ago in many countries. Most Americans under 35 have never been vaccinated and most over 35 have not received booster immunizations since the early 1970s. If a bioterrorist attack were to occur, it would be critical to know who already had effective immunity and would not need to be vaccinated, leaving another dose available for someone else.
Current recommendations relating to smallpox vaccination has been that people with repeated exposure to smallpox, for example travelers to endemic areas, should be revaccinated every five years. This study suggests that such reimmunizations may not be necessary because multiple vaccinations achieve only marginally higher levels of antibody and virus neutralizing activity than single vaccination.
Writing in the article, Dan L. Longo, MD, National Institute on Aging, states “A major question posed today is whether those individuals vaccinated 40 or more years ago would be protected in the event of smallpox exposure. This may be a critical question because the availability of smallpox vaccines is limited and currently inadequate for a mass inoculation program. We found that vaccinated subjects maintain what appear to be protective levels of neutralizing antibodies to vaccinia indefinitely and do not require booster vaccinations even if they are many decades removed from primary vaccination. These data imply that limited supplies of vaccine can be more usefully applied to individuals who have never been vaccinated, primarily individuals born after 1972.”
The HPV vaccine, sold as Gardasil in the U.S., is intended to prevent four strains of the human papillomavirus, the most common sexually transmitted infection in the world. The vaccine also prevents against cervical cancer. While the vaccine represents a significant public health advance, a new article in the Journal of Law, Medicine & Ethics
Full Post: State mandates for HPV vaccination unwarranted and unwise
Individuals younger than 50 who have been previously vaccinated do not appear to have a substantially different immune response to a half-dose of influenza vaccine than to a full dose, according to a report in the December 8/22 issue of Archives of Internal Medicine. This suggests that half-dose vaccination in healthy young individuals may be
Full Post: Half-dose vaccination in healthy young individuals may be effective in times of vaccine shortage
The National Association of County and City Health Officials (NACCHO) has announced a donation of up to one million doses of FluMist (Influenza Virus Vaccine Live, Intranasal) by MedImmune in a partnership aimed at increasing influenza awareness and vaccinations in underserved communities and populations. NACCHO will make these donated doses of vaccine available to selected state
Full Post: NACCHO to donate up to one million doses of FluMist
Despite recent doubts about its effectiveness, the influenza vaccine does give valuable protection against illness, hospital admission and death caused by influenza, and people over 65 should have the flu jab this winter, say experts on bmj.com. Several prominent media articles have suggested that the flu vaccination programme for the over 65s is not worthwhile.
Full Post: Seniors should have the flu jab this winter, say experts
Results from the Step study, a test-of-concept efficacy study of a Merck & Co., Inc. HIV vaccine candidate, were published online in two papers in The Lancet this week. These analyses of the Step study are being conducted, presented and published to inform the continued search for an effective HIV vaccine. The two analyses, one
Full Post: Analyses of Merck’s HIV vaccine ‘Step’ study