The 2013 influenza season is well underway with most of the United States reporting a greater than average volume at most hospitals. Many of those seeking medical attention are doing so with Influenza like symptoms. I have compiled a list of FAQs that have recently come up:
As we head into another influenza season we are trying to improve our hospital staff vaccination rates. The goal of vaccinating hospital staff is two fold. First to keep the staff from getting influenza themselves and second by keeping the staff from getting ill they do not become involuntary spreaders of disease to hospitalized patients. Thereby protecting the chronically ill patients at the hospital. The second reason described is often forgotten and overlooked. I cannot begin to count the number of times I have been told that they do not need a flu shot because they don’t sick from the “flu”.
Remember it is more about protecting patients, the weak and infirm who may not have the ability to tolerate a respiratory tract infection
After that discussion the next heard is concerns over vaccinating patients and how the vaccine can or will make them ill. Often cited is a concern that a post vaccination fever is not discern able from a post op fever. Archives of Internal Medicine published this study in 1996 by Nichol et al. The study, a randomized placebo controlled prospective trial looked at the number of symptoms including minor ones such as injection site pain and fever post vaccination compared to placebo. Their findings include that fever post vaccination is no more common than placebo.
This review was published in the Nov 18th, 2010 issue of the New England Journal of Medicine. It does a great job detailing the vaccine production and some of the pitfalls in developing newer universal vaccines; influenza vaccines that do not require annual shots. It is a must read.
Lately I have been approached several times about the incidence of fever post vaccination. Data suggests that it is a rare and benign issue at best. In a placebo controlled trials it was no more frequent than in the control group.
Placebo-controlled trials demonstrated that among older persons and healthy young adults, administration of TIV is not associated with higher rates for systemic symptoms
Therefore the presence of low grade fever or the concern for fever should not be a contraindication for vaccination.
Also of interest is the recurring concern for Guillian-barre. In this series there were no cases in over 4 million doses administered.
Just another reason to have the elderly vaccinated every year with Influenza vaccine along with appropriate 23-valent pneumococcal vaccine (when is pneumovax given?).
This prospective study in Hong Kong observed readmission rates among 36,000 elderly patients. The study found statistically significant decrease in the number of deaths, pneumonia, strokes and myocardial infarctions among the studied population.
One may ask “What does a vaccine have to do with prevention of stroke or MI?”. The reasons are that this population is at risk for these stressful infections. The burden of these conditions (sepsis) can further stress a compromised elderly patient and can “push” them into a stroke or and MI. These vaccine may not even completely prevent the illnesses themselves but by reducing the stress of the illness can go a long way in reducing morbidity and mortality from other conditions such as MI and strokes.
Also of note that very few if any “side effects” that are often cited in the lay media were seen. If there were more side effects it should have been seen in the higher hospitalization rate. In fact the vaccinated group had lower death and hospitalization rates.
For more information read the reference:
1. Hung, Ivan F N, Angela Y M Leung, Daniel W S Chu, Doris Leung, Terence Cheung, Chi-Kuen Chan, Cindy L K Lam, et al. 2010. Prevention of acute myocardial infarction and stroke among elderly persons by dual pneumococcal and influenza vaccination: a prospective cohort study. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 51, no. 9 (November): 1007-16. doi:10.1086/656587. http://www.ncbi.nlm.nih.gov/pubmed/20887208.
What Gullian barre? Guillain barre sydrome is a neurologic condition where the body immune systems antibodies misrecognizes parts of the nervous system as foreign and attacks it. The host can develop muscle weakness and even paralysis. This can be a serious condition. Fortunately it is very rare. This is NOT caused directly by a vaccine but by the immune system itself. This can therefore happen with anything that stimulates the immune system to produce more antibodies. In other words infection itself can produce GBS. Most GBS is caused by viral infections and by a common bacteria that causes food poisoning called Campylobacter.
There are about 10-20 cases of GBS per million population in any given year, this is known as the “background rate” of occurrence. This has been closely watched since the initial cases of GBS were reported in the 1970s and does not appear to have changed that much with subsequent influenza seasons. (Roper AH. The Guillain barre syndrome. N Engl J Med 1992 326:1130-6)
The first series of GBS related to vaccination was reported in JAMA in 1980. This was based on data collected from the 1976 influenza vaccination season where it was believed that people were getting GBS from the vaccination. In this study they cite an attributable risk of 13 cases of GBS per 100,000 population vaccinated (an alarmingly high number) based on a collection of 32 cases with a history of vaccination. They needed a background rate for comparison. Due to the lack of public health records for GBS at that time they called local neurologists on the roster of the local medical associations in the state of Ohio and asked them about all the cases they had seen in the studied time interval. With this information they arrived at a background prevalence of 2.6 cases per 100,000. Of course this data was met with appropriate alarm, it turned out to be a public relations fiasco.
More detailed studies of the initial finding were later published regarding the 1976 swine flu vaccination where 40 million people were vaccinated and possible 532 cases of Guillian Barre were reported and 32 people died. This gives a rate of
about 13 cases per million. One tenth the number originally cited in the smaller study and a number more in the middle of the expected background rate. Definitely less alarming.
Data collected prospectively in subsequent years have failed to demonstrate any increased risk.
The risk from vaccination therefore may add an additional risk of perhaps up to 1 additional case per 1,000,000 administered doses of influenza vaccine this is a very small number compared with the original 130 cases per 1,000,000 that was reported in the 1980 article. This is rare enough to go so far as to say that there is probably no causal relationship influenza vaccination and GBS.