Archive for April, 2014

What is in a vaccine and why?

Wednesday, April 30th, 2014 (last updated)

The main ingredient of any vaccine is the disease-causing virus, bacteria or toxin, but a number of other components are needed to make the final vaccine as safe and effective as possible.

Killed and live vaccines

Vaccines contain ‘killed’ (inactivated) or ‘live’ versions of the disease-causing virus, bacteria or toxin. These are known as the vaccine antigen.

Killed vaccines contain previously virulent micro-organisms that have been destroyed with chemicals or heat. These vaccines are also known as inactivated or ‘dead’. Examples of killed vaccines are the flu jab, whooping cough vaccine, and polio vaccine.

Live vaccines, also called ‘attenuated vaccines’, contain a version of the bacteria or virus that’s been weakened (though not destroyed) to make sure it can’t cause disease. Examples of ‘live’ vaccines are the BCG vaccine, MMR vaccine and the children’s nasal spray flu vaccine.

Both types of vaccine work by stimulating the immune system so it thinks it’s being attacked by the active germ. Your body responds by producing antibodies that stay in your system to protect you in the future.

Because a live vaccine is the closest thing to a natural infection it produces a strong immune response and often confers lifelong immunity.

Killed vaccines generally produce a weaker immune response so it often takes several doses or a ‘booster’ to maintain your immunity.

Thiomersal (mercury) in vaccines

Thiomersal is a preservative which contains small amounts of mercury. It’s used to prevent the growth of bacteria or fungi in the vaccine.

High doses of mercury can be toxic to the brain and other organs. However, no harmful effects have been linked with the level of thiomersal used in such small amounts in vaccines.

Although there have been concerns in the past that thiomersal-containing vaccines can cause autism, there is no scientific evidence that this is the case.

The World Health Organization (WHO) has stated that there is no risk from thiomersal in vaccines. Read the full WHO statement.

Thiomersal is no longer used in any of the vaccines routinely given to babies and young children in the NHS childhood immunisation programme.

Adjuvants in vaccines

Adjuvants work to boost our immune response to a vaccine and make it more effective and long-lasting. Using an adjuvant makes it possible to reduce the amount of antigen used in a vaccine and sometimes the number of doses that need to be given.

The amount of adjuvant used in a vaccine is very small and has been shown to be safe, although adjuvants in vaccines can be associated with minor reactions such as a small lump or redness at the injection site.

Most killed vaccines contain a very small amount of aluminium-based adjuvant. Although aluminium can be toxic in large quantities, no harmful effects are seen with the level of aluminium used in such small amounts in vaccines.

Gelatin in vaccines

Gelatin derived from pigs is used as a stabilising agent in some vaccines. Stabilisers are added to vaccines to help protect them from the effects of heat or freeze-drying and to also help maintain the shelf life of the vaccine.

The only vaccines containing gelatin in the UK routine schedule are the MMR vaccine and the children’s nasal flu vaccine.

There have been a small number of allergic reactions to vaccines containing gelatin so people with a known allergy to gelatin are advised to consult their doctor before receiving a gelatin-containing vaccine.

Religious groups such as Muslims and Jews may be concerned about using vaccines containing gelatin from pigs, however many faith group leaders have stated that the use of gelatin in vaccines is acceptable and doesn’t break any religious rules. Read more about religious opinion on pork gelatin in vaccines.

Human serum albumin in vaccines

Human serum albumin is a substance from human blood. It’s a protein used to stabilise a vaccine and maintain its quality during storage.

The serum used in vaccines comes from screened blood donors and the manufacturing process ensures that any risk of transmitting disease is eliminated.

Human serum albumin is used as a stabiliser in the MMR vaccine.

Eggs in vaccines

Two vaccines in the UK routine schedule contain small amounts of egg protein – MMR vaccine and flu vaccine.

Flu vaccine is grown on hens’ eggs and is capable of triggering an allergic reaction. Children and adults with egg allergy are therefore advised to have an alternative such as an egg-free inactivated flu vaccine.

MMR vaccine is grown on cells from chick embryos, which isn’t the same as hens’ eggs and therefore doesn’t trigger an allergic reaction. Children and adults with severe egg allergy can safely receive the MMR vaccine.

Formaldehyde in vaccines

Formaldehyde, widely known as an embalming fluid, is a chemical that’s also used in the production of killed vaccines. It’s used very early in the manufacturing process to kill or ‘inactivate’ the bacteria, virus or toxin.

Once the antigens are inactivated the formaldehyde is diluted out but it’s possible trace amounts may remain in the final vaccine.

Formaldehyde can be harmful in high concentrations, however there are no health concerns about the small amounts found in vaccines. Formaldehyde can be found naturally in our bloodstream. It helps with metabolism and is present at levels far higher than we would be exposed to in vaccines.

Antibiotics in vaccines

Antibiotics are added to some vaccines to prevent growth of bacteria during production and storage of the vaccine. They can only be found in tiny amounts in the final vaccine.

Antibiotics that are associated with allergic reactions, such as penicillin, generally aren’t used in vaccines. However, MMR vaccine contains tiny amounts of an antibiotic called neomycin which is capable of triggering an allergic reaction. Anyone known to be allergic to neomycin should consult their doctor before receiving the MMR vaccine.

How to find out what’s in a vaccine

A complete list of ingredients for each vaccine is given in the Patient Information Leaflet (PiL) and Summary of Product Characteristics (SPC).

These ingredient lists include any products used in the making of a vaccine, even though most are only needed during the production process and are removed, or only found in tiny amounts, in the final vaccine.

Visit the European Medicines Agency website to search for the SPC of a particular vaccine.

vaccines

Source:
NHS Choices

How many vaccine-preventable outbreaks have to happen before we realize this?

Tuesday, April 29th, 2014 (last updated)

vaccines work Unicef

Source:
Unicef

New vaccine hope for leading viral cause of birth defects

Monday, April 28th, 2014 (last updated)

Experts in infection and immunity have made a path-finding discovery that could lead to the development of a vaccine for a health-ravaging virus that affects around 50% of adults in the UK.

Cytomegalovirus (CMV) is the leading viral cause of congenital birth defects, with 1 in 750 babies in the UK being born with permanent disabilities – these include blindness, deafness and brain damage – as a result of infection within the womb.

Scientists from Cardiff have uncovered a novel defence mechanism to control disease, using the most common form of white blood cell – neutrophils.

Although it has long been known that neutrophils are important in killing bacterial infections, it was largely thought that they were specifically designed for this cause; the fact that they can also fight a viral attack is a major breakthrough according to Dr Ian Humphreys from the University’s School of Medicine:

“Our study shows that neutrophils protect our organs from CMV by producing a protein called TRAIL that can directly kill virus-infected cells. Our body attracts the neutrophils to where the virus is replicating by producing the protein IL-22, which acts as a homing signal.

“Disease may actually be prevented if we can teach the immune system to quickly send antiviral neutrophils to the first site of infection. We are now developing a vaccine that may protect the body against CMV. Our findings may also have implications for other destructive viruses such as flu, hepatitis and even HIV.”

Dr Chris Benedict from the La Jolla Institute for Allergy and Immunology (San Diego, California) said:

“Neutrophils are the rapid-response arm of the immune system’s war against infection.  The discovery of a new molecular mechanism for neutrophil mobilization and execution in the fight against CMV is very exciting, and provides key insights for developing more effective vaccines and therapies to combat this little-known viral pathogen.”

Currently there is no known treatment for CMV. Given that the virus spreads via bodily secretions such as urine, saliva and breast milk, scientists at Cardiff sought to understand how to protect mucosal sites from infection, and how to prevent the virus taking its grip in other important organs such as the liver.

The virus is also a major reason behind life-threatening diseases in bone marrow and organ transplant recipients and is known to have a major impact on the immune system of even the healthiest of adults.

The research was conducted as part of a collaboration between Cardiff University, The Wellcome Trust, Sanger Institute (Cambridge), the University of Oxford and La Jolla Institute for Allergy and Immunology in California.

The paper is published in the journal Cell Host & Microbe.

New vaccine hope for leading viral cause of birth defects Click here

Source:
Cell Host & Microbe

Afghanistan: stopping polio in its tracks

Sunday, April 27th, 2014 (last updated)

Vaccinators are out in full force after a new case of polio was discovered in Afghanistan’s capital.

Source:
Unicef

Melanoma vaccine

Saturday, April 26th, 2014 (last updated)

The University of Adelaide has developed a vaccine that is giving new hope to thousands of Australians diagnosed with melanoma.

Source:
9NewsAdel

Measles on the rise as immunization falls

Friday, April 25th, 2014 (last updated)

measles

In the history of medicine few discoveries have had the impact that vaccination has had. For the sheer number of lives saved, vaccination ranks with clean water: Unicef estimates it saves nine million lives a year. Immunisation has eradicated smallpox and turned once ubiquitous illnesses such as polio into rarities. Despite this, a legacy alternating between complacency and hostility towards immunisation continues to have serious consequences.

Measles is a good example; it is incredibly infectious, with each case leading to 12-18 secondary infections. It is airborne, readily transferable and difficult to avoid. Its effects can be devastating and even fatal, killing 160,000 annually. The vaccine saves more than a million lives a year but, due to the tenacity of measles, the collective resistance of the population has to be high to stop it becoming endemic, so individuals with immunity provide a “firewall”, protecting those who cannot be vaccinated, such as infants. For a disease as virulent as measles, the herd immunity has to be about 94 per cent.

Outbreaks on the rise 
Yet this isn’t happening and outbreaks are on the rise worldwide – California and New York are in the midst of their greatest measles outbreaks in decades; and 2011 saw 26,000 cases of measles in Europe, nine deaths and 7,288 hospitalisations. Infections in the UK have surged to 20-year highs. The same trend is evident in Ireland – the 402 cases in 2010 were more than double the 2009 figure. One outbreak in west Cork in 2012 infected more than 50 people, 88 per cent of whom had not received even a single dose of the vaccine. In north Cork, vaccination figures of a shockingly low 26.5 per cent have been reported.

This apathy towards or opposition to vaccination is not solely confined to MMR; cases of whooping cough in Ireland have increased dramatically too, despite a simple vaccine being available. Protection rates this low are courting disaster.

It is unsurprising teenagers have been badly affected: these children were toddlers back in 1998 when the now discredited research from Andrew Wakefield linked the MMR vaccine to autism.

Yet sensationalism sells – by 2002, MMR was the dominant science scare story. Anti-MMR campaigners abounded, and targeted non-science journalists, ensuring their stories were uncritically disseminated and perpetuating the false impression that MMR was dangerous.

This had tragic consequences; and the un-immunised continue to be the biggest victims of this.

Sadly, much of the opposition to vaccines is psychological in nature – as a 2011 New England Journal of Medicine editorial put it: “the spectrum of anti-vaccinationists ranges from people who are simply ignorant about science . . . to a radical fringe element who use deliberate mistruths, intimidation, falsified data and threats of violence in efforts to prevent the use of vaccines and to silence critics”.

Studies have found anti- vaccination campaigners tend to have traits of denialism, conspiratorial thinking, reasoning flaws, preference for anecdote over data and low cognitive complexity in thinking patterns.

Some of the staunchest opposition comes from the alternative medicine community: a study of Australian homeopaths, for example, showed 83 per cent warned patients against immunisation while peddling useless homeopathic interventions.

Conspiracy theories about vaccination abound, usually claiming it is just a money-spinning tool of “big pharma”, despite the fact most vaccines have low profit margins.

Parents who deny their children appropriate vaccines are putting not only their own children but other vulnerable people at risk. Vaccination has saved countless lives. Let us not take that for granted.

Source:
Dr. David Robert Grimes – Irish Times

Yeah, I’m vaccinated

Thursday, April 24th, 2014 (last updated)

I'm vaccinated

Source:
VacciNewsNet

Anecdotal ‘Amish-don’t-vaccinate’ claims disproved by fact-based study

Wednesday, April 23rd, 2014 (last updated)

amish

The various vaccine manufactroversies that have spread in the wake of the Andrew Wakefield’s bogus claims that the measles component of the MMR vaccine might be linked to autism are too numerous to unpack in one brief blog post. One of the most persistent has been the Amish fallacy: Most Amish don’t vaccinate; there’s almost no record of autism in Amish communities; ergo, vaccines cause autism. (This argument has also been used, time and time and time again, to illustrate the efficacy of a proposed vaccinated-versus-unvaccinated study.)

Not surprisingly, no part of the Amish fallacy — which has been kicking around for over a decade and gained new prominence and attention with this, purely anecdotal 2005 dispatch* — is true. Over the years, Ken Reibel at Autism News Beat has documented the problems with the Amish report, although the myth still persists.

Yesterday, Reuters Health reported on a recent study in Pediatrics titled “Underimmunization in Ohio’s Amish: Parental Fears Are a Greater Obstacle Than Access to Care.” The study found that majority of Amish parents do, in fact, vaccinate their children…and among the minority that don’t, the most common reasons cited were the same anti-vaccine fueled fears that have infected people around the country.

Unlike the theories propagated by anti-vaccine activists, this study was definitely not anecdotal: It was based on surveys sent to hundreds of families in Holmes County, which has a large number of Amish families. As Reuters reports, “Of 359 households that responded to the survey, 85 percent said that at least some of their children had received at least one vaccine. Forty-nine families refused all vaccines for their children, mostly because they worried the vaccines could cause harm and were not worth the risk.”

The study’s conclusions summarize the issue quite succinctly:

The reasons that Amish parents resist immunizations mirror reasons that non-Amish parents resist immunizations. Even in America’s closed religious communities, the major barrier to vaccination is concern over adverse effects of vaccinations. If 85% of Amish parents surveyed accept some immunizations, they are a dynamic group that may be influenced to accept preventative care. Underimmunization in the Amish population must be approached with emphasis on changing parental perceptions of vaccines in addition to ensuring access to vaccines.

It’ll be interesting to see how this plays out in the days to come…and what objections will be raised to invalidate this latest piece of evidence.

* Correction: In the first iteration of this post, I attributed the Amish-don’t-vaccinate myth to the 2005 UPI dispatch linked to above; as was pointed out in the comments, it has been kicking around since at least 2000.

Vaccines Work

Tuesday, April 22nd, 2014 (last updated)

vaccines work

Source:
Unicef

Innovative vaccines companies and the ‘decade of vaccines’

Monday, April 21st, 2014 (last updated)

decade of vaccines

Source:
IFPMA