Showing posts with label vaccination. Show all posts
Showing posts with label vaccination. Show all posts

Tuesday, April 26, 2016

Vaccinations are more effective when administered in the morning

Vaccine
Credit: National Cancer Institute
New research from the University of Birmingham has shown that flu vaccinations are more effective when administered in the morning.

26 april 2016--The findings, published in the journal Vaccine, suggest administering vaccinations in the morning, rather than the afternoon, could induce greater, and thus more protective, antibody responses.
24 general practices in the West Midlands, UK, were analysed between 2011 and 2013 in a cluster-randomised trial during the annual UK influenza vaccination programme.
276 adults aged over 65 were vaccinated against three strains of influenza, either in morning surgeries (9-11am) or afternoon surgeries (3-5pm).
In two of the three given influenza virus strains, those in the morning cohort saw a significantly larger increase in antibody concentration one month following vaccination, when compared with those in the afternoon cohort. In the third strain, there was no significant difference between morning and afternoon.
Dr Anna Phillips, the Principal Investigator of the study from the School of Sport, Exercise and Rehabilitation Sciences at the University of Birmingham explained, "We know that there are fluctuations in immune responses throughout the day and wanted to examine whether this would extend to the antibody response to vaccination. Being able to see that morning vaccinations yield a more efficient response will not only help in strategies for flu vaccination, but might provide clues to improve vaccination strategies more generally."
The influenza vaccination is part of the seasonal vaccination programme carried out by general practices across the UK, and in many other countries, with a particular focus on patients over 65 years old.
Despite this, the influenza virus is responsible for between 250,000 and 500,000 deaths each year worldwide. The age-related decline in immunity reduces the ability of older adults to produce adequate antibody responses following vaccination, compromising the given protection.
Other interventions to improve outcomes of vaccination have been attempted with limited success, including exercise routines and additives to the vaccine itself.
Professor Janet Lord, a co-investigator on the study from the Institute of Inflammation and Ageing at the University of Birmingham, said, "A significant amount of resource is used to try and prevent flu infection each year, particularly in older adults, but less than half make enough antibody to be fully protected. Our results suggest that by shifting the time of those vaccinations to the morning we can improve their efficiency with no extra cost to the health service."
The team will now look to investigate further in a large scale study. This is important to see if the morning vaccination strategy benefits a wide range of over 65s including those with conditions like diabetes, liver and kidney disease that impair immunity. They will also look to see if the morning vaccination strategy is effective for the pneumococcal vaccine that protects against pneumonia; a vaccine recommended to all individuals aged 65 years old in the UK.

More information: "Morning vaccination enhances antibody response over afternoon vaccination: a cluster-randomised trial," VaccineDOI: 10.1016/j.vaccine.2016.04.032


Provided by University of Birmingham

Tuesday, July 08, 2008

Finding suggests novel ways to boost vaccination or natural defenses

8 july 2008--Our bodies rely on the production of potent, or 'high affinity', antibodies to fight infection. The process is very complex, yet Sydney scientists have discovered that it hinges on a single molecule, a growth factor, without which it cannot function.
There is much we do not yet understand about our immune system. In simple terms, our bodies produce B cells, which make antibodies, and T cells, which help them. Ways in which these cells operate and interact with each other are still coming to light.
Roughly eight years ago, a new subset of T cells, T follicular helper (TFH) cells, was identified. This important class of T cells operates in specific environments termed 'germinal centres', specialised areas within lymph organs where B cells proliferate to form high affinity antibodies whenever we fight infection. TFH cells play a critical role in that they communicate with, and help activate, B cells.
The novel finding made by Dr Cecile King and PhD student Alexis Vogelzang, from the Garvan Institute of Medical Research in Sydney, was that the molecule interleukin 21 (IL-21) is a growth factor for TFH cells. A paper detailing this finding was published online today in the prestigious international journal Immunity.
A cytokine, or chemical messenger, IL-21 is already well known to immunologists. While its newly identified growth factor role is only one of several functions, that function is fundamental. Without IL-21, the all-important TFH cells could neither develop nor survive.
Dr Cecile King, head of the Mucosal Autoimmunity Group at Garvan, has been investigating the roles of IL-21 for several years. "We already knew that IL-21 was produced by TFH cells and that it was a major initiator of proliferation in B cells," she said. "We were surprised to find that TFH cells not only produce IL-21, they also absolutely need it to survive and they utilise it to function."
"We showed that if you take a mouse genetically deficient in IL-21 and immunise it, you don't get TFH cells and you don't get antibody production. Conversely, if you put IL-21 receptor sufficient, or normal, T cells into the same mouse, where of course the B cells remain abnormal, you recover the normal immune reaction."
"These specialised T cells are thought to be the ones that direct traffic. They are the only ones that can move into the B cell zone and initiate high affinity antibody production."
"Without IL-21, we probably wouldn't be completely immunodeficient, just severely compromised. In addition to the high affinity antibodies we're talking about, our bodies also produce a lot of low affinity antibodies for mopping up infection. That low level response happens around-the-clock and is one of our body's first lines of defence."
"You could say that IL-21 directs the most finely-tuned aspect of our immune response. The highly specialised weaponry developed on-the-spot to target aggressive invaders."
"This finding suggests novel ways to boost vaccination or natural defences."