Wednesday, July 12, 2017

Are Vaccines Safe ???

Reducing and eliminating the diseases that vaccines prevent is one of the top achievements in the history of public health. But some how the number of anti vaccinators increased from the past. Its mainly through the widespread of news regarding misconceptions of vaccines. The widespread fear that vaccines increase risk of autism originated with a 1997 study published by Andrew Wakefield, a British surgeon. The article was published in the Lancet, a prestigious medical journal, suggesting that the measles, mumps, rubella (MMR) vaccine was increasing autism in British children. But later this paper was completely discredited due to serious procedural errors. ts publication set off a panic that led to dropping immunization rates. However that went unnoticed by many as usual and still rumours continue to spread.
Vaccines need additives to improve the way they work, increase their shelf life and make them as safe and effective as possible. The three main substances added to vaccines are:
  • adjuvants or enhancerto make the vaccine more effective
  • stabiliser to stop the vaccine deteriorating when it is exposed to changes in the environment, such as light and temperature
  • preservativesto increase the vaccine’s shelf life.
Any licensed vaccine is rigorously tested across multiple phases of trials before it is approved for use, and regularly reassessed once it is on the market. Scientists are also constantly monitoring information from several sources for any sign that a vaccine may cause an adverse event. Most vaccine reactions are usually minor and temporary, such as a sore arm or mild fever. In the rare event a serious side effect is reported, it is immediately investigated. So available vaccines remain safe.
Common Myth is that: Vaccines can cause autism bacause they contain ingredients that are dangerous. The most often blamed culprit is thimerosal.
Thimerosal, which is approximately 50% mercury by weight, has been one of the most widely used preservatives in multi-dose vaccines. It is metabolized or degraded to ethylmercury and thiosalicylate. Ethylmercury is an organomercurial that should be distinguished from methylmercury, the chemical actually known to cause harm. Methylmercury is the type of mercury found in certain kinds of fish. At high exposure levels methylmercury can be toxic to people. But over a lifetime, everyone is exposed to some methylmercury through food and environment. The different type of mercury in thiomersal has the ability to be metabolised at a faster rate and they get excreted quickly from our body. Thus thiomersal is less likely to produce harmful effects on the human body.
Thimerosal is used to prevent the growth of microbes during the manufacturing process..Thiomersal is more commonly used in mixed dose vaccines. Live and single dose vaccines do not necessarily need agents likeThimerosal. When each new needle is inserted into the multi-dose vial, it is possible for microbes to get into the vial. The preservative, thimerosal, prevents contamination in the multi-dose vial when individual doses are drawn from it. Receiving a vaccine contaminated with bacteria can be deadly.
In developing countries like India, multi dose vaccines are still being used at large as these countries cannot afford to make single dose vaccines and not to use preservatives like thiomersal. The cost of producing single dose vaccines and the need to refrigerate them for proper storage and transport makes the use of thiomersal absolutely necessary. However, USA and some countries have decreased the use of thiomersal in vaccines only as a precaution. But even in those countries, it’s use has not been discontinued altogether.
Research indicates there is no difference in the rates of autism between vaccinated and unvaccinated children. While autism may seem more common in recent years, This is because the diagnosis of autism now includes children with milder symptoms who would not have been included in the past. There is also greater public awareness of autism, and more parents are seeking help. Even today the true causes of autism remain a mystery, but to the discredit of the autism-vaccination link theory, recent studies provides evidence that autism develops in utero, well before a baby is born or receives vaccinations. There is no evidence of a link between MMR vaccine and autism or autistic disorders. Still anti-vaccine ideologists uses ”thiomersal” and “mercury poisoning” as their main weapon for propagating base-less ideas and creating alarm in minds of parents.
Another myth is that Babies Immune system get overloaded with vaccines. Based on the number of antibodies present in the blood, a baby would theoretically have the ability to respond to around 10,000 vaccines at one time. Even if all 14 scheduled vaccines were given at once, it would only use up slightly more than 0.1% of a baby’s immune capacity. And scientists believe this capacity is purely theoretical. The immune system could never truly be overwhelmed because the cells in the system are constantly being replenished. In reality, babies are exposed to countless bacteria and viruses every day, and immunizations are negligible in comparison.
WHO has closely monitored scientific evidence relating to the use of thiomersal as a vaccine preservative for over 10 years, in particular through its independent expert advisory group, the Global Advisory Committee on Vaccine Safety. The Committee has consistently reached the same conclusion: there is no evidence to suggest that the amount of thiomersal used in vaccines poses a health risk. Immunization with thiomersal-containing multi-dose vaccines currently protects at least 64% of all infants and children against four diseases with high mortality rates: diphtheria, tetanus, pertussis and Haemophilus influenza type b. The use of thiomersal-containing vaccines to protect against these diseases averted at least 1400000 child deaths in 2010. Thiomersal-containing vaccines are being used in over 120 countries. Removing thiomersal completely from vaccines would require either using alternative preservatives or using preservative-free single dose vaccines exclusively. Alternatives would incur significant costs for development and regulatory approval, thereby limiting the ability to offer affordable vaccines.
Immunisation is one of our most significant achievements. It saves around 3 million lives world-wide each year and helps to prevent outbreaks and hospitalisations from vaccine-preventable diseases. As a parent its your duty to protect your child by ensuring vaccines are given on time. Vaccine-preventable diseases are still common in many countries. Increased travel and immigration means the risks are real.

In reality, the benefits of vaccination greatly outweigh the risk i.e., having a vaccination is much safer than not having one. They're not 100% effective in every child, but they're the best defence against the epidemics that used to kill or permanently disable millions of children and adults. Choosing to protect your child with vaccines is also a choice to help protect your family, friends, and neighbors. i.e. to get vaccinated means to protect ourselves and to protect those around us. Successful vaccination programmes depend on the cooperation of every individual to ensure the wellbeing of all. We should not rely on people around us to stop the spread of disease; we, too, must do what we can.

Tuesday, July 4, 2017

Why We Want to Redefine Kg???

What we call a kg might soon change in future.? Yes you heard right, a substantial change to the International System of Units (SI) is currently under discusstion and might be a reality by 2019. The General Conference on Weights and Measures (CGPM) is scheduled to have its 26th meeting in 2018 and will likely vote on a proposal put forward by the International Committee for Weights and Measures (CIPM) to revise the SI. According to this proposal, the structure of the SI will change fundamentally. The present SI is built upon seven base units: the metre, the second, the kilogram, the ampere, the kelvin, the mole, and the candela. The goal of the new SI is to define all of these units completely in terms of fundamental constants with exact values. Some constants, such as the speed of light, are currently defined in this way, as exact quantities.
At present, the kilogram is the SI unit of mass and is equal to the mass of the international prototype of the kilogram which is an artefact, not a constant of nature. The kilogram is the only SI unit still based on a physical object. The kilogram will be defined in terms of a quantum-mechanical quantity known as the Planck constant (h) which will be assigned an exact fixed value based on the best measurements obtained worldwide.
The International Prototype Kilogram(IPK) or “Le Grand K” or “Big K” is the palm-sized platinum and iridium cylinder that for 126 years has defined the kilogram from a high-security vault outside Paris where it was protected from dust, moisture, fingerprints, and other corruptions of the outside world and was hailed as the “perfect” kilogram”. Since hydrocarbons on fingertips or moisture in the air could contaminate its pristine surface, it goes untouched for decades, under triple lock and key at the International Bureau of Weights and Measures. Every 40 years, the weight is ushered from its chamber, washed with alcohol, polished, and weighed against 80 official replicas hand-delivered from laboratories around the world.
It is seen that world’s most perfect weight isn’t so perfect anymore. In its most recent weigh-in in 1988, it was found to be 0.05 milligrams,about the weight of a grain of sand, lighter than its underling replicas. But Le Grand K’s guardians are not sure if it is Le Grand K that has slimmed, or whether its comparators have gained weight. Whatever is right ,its not good for a standard to change. You may think why should we care whether a kilogram in a vault is “perfect” or not? We must, as a small discrepancy can become a gargantuan one if you’re dealing with a large quantity, for eg. a full tanker of Rice. Also the kilogram is used as a building block in other measurements. As in the case of the joule( the amount of energy required to move a one-kilogram weight one meter) and candela, a measure of the brightness of light, is measured in joules per second. Therefore if the kilogram is flawed, so are the joule and candela, which could eventually cause problems in an array of industries, particularly in technology.
The slighter instability of big K is unacceptable in precise fields like medicine or engineering, where tiny differences can cause immense problems. Therfore a more reliable standard has to be defined for measuring kg. For instance, the meter, which was originally represented by a metal bar, was redefined in 1983 as the distance light travels in a vacuum during 1/299,792,458 of a second. However standardizing the kilogram is little trickier as the standard could not be changed physically due to environmental changes, accidental damage, or even sabotage. To overcome such risks and also to improve our system of units, we need a definition that depends on nothing other than the value of a fundamental constant, e.g. the Planck constant h, a fixed quantity linked to E=MC2 and quantum theory that specifies the amount of energy carried by a single particle of light, or photon.

To be continued....

Saturday, July 1, 2017

Babies & Vaccination

As a parent, everyone wants best for their children. Protecting your child's health is one of your main concerns. So most of us choose to vaccinate children to prevent previously devastating, widespread disease by significantly reducing childhood infection rates. Vaccines not only help keep your child healthy, they help all children by stamping out serious childhood diseases.
We may often wonder why vaccines are given at such an early stage?? Its because the diseases they prevent often strike at an early age. Since their immune systems are not yet fully mature and also their stomachs produce less acid, making it easier for ingested bacteria and viruses to multiply. These factors leave them more susceptible than older kids and adults to the devastating effects of these serious diseases. Infants need 2-5 doses of each recommended vaccine. Each dose increases your baby’s protection against a specific disease. For the earliest and best protection, your baby needs to complete each vaccine series on time.
Next Question is whether your infant's immune system can handle all the vaccines. The truth is that infants can respond to multiple vaccines, which play a vital role in helping their immune system avoid diseases. Babies may get some temporary immunity (protection) from mother during the last few weeks of pregnancy, but only for the diseases to which mom is immune. Breastfeeding may also protect your baby temporarily from minor infections, like colds. These antibodies do not last long, leaving your baby vulnerable to disease. Natural immunity occurs when your child is exposed to a disease and becomes infected. It is true that natural immunity usually results in better immunity than vaccination, but the risks are much greater. A natural chickenpox infection may result in pneumonia, whereas the vaccine might only cause a sore arm for a couple of days.
Vaccines are made from the same germs (or parts of them) that cause disease; for example, polio vaccine is made from polio virus. But the germs in vaccines are either killed or weakened so they won’t make you sick. Vaccines containing these weakened or killed germs are introduced into your body, usually by injection. Your immune system reacts to the vaccine in a similar way that it would if it were being invaded by the disease i.e. by making antibodies. The antibodies destroy the vaccine germs just as they would the disease germs like a training exercise. Then they stay in your body, giving you immunity. If you are ever exposed to the real disease, the antibodies are there to protect you.
Vaccines, like any medication, may cause some side effects. Most of these side effects are very minor, like soreness where the shot was given, fussiness, or a low-grade fever. The se side effects typically only last a couple of days and are treatable. For example, you can apply a cool, wet washcloth on the sore area to ease discomfort. Serious side effects following vaccination, such as severe allergic reaction, are very rare and doctors and clinic staff are trained to deal with them. The disease-prevention benefits of getting vaccines are much greater than the possible side effects for almost all children.
Some people have suggested that thimerosal (a compound that contains mercury) in vaccines given to infants and young children might be a cause of autism, and others have suggested that the MMR (measles- mumps-rubella) vaccine may be linked to autism. However, numerous scientists and researchers have studied and continue to study the MMR vaccine and thimerosal, and reach the same conclusion: that there is no link between them and autism. 
Getting every recommended dose of each vaccine provides your child with the best protection possible. Depending on the vaccine, more than one dose is needed to build high enough immunity to prevent disease, boost immunity that fades over time, make sure people who did not get immunity from a first dose are protected, or protect against germs that change over time, like flu. Every dose of a vaccine is important because they all protect against infectious diseases that are threats today and can be especially serious for infants and very young children.
The recommended schedule is designed to protect infants and children by providing immunity early in life, before they are exposed to life-threatening diseases. I prefer and advise every parent to vaccinate as the consequences of these diseases can be very serious, and even life-threatening, for infants and young children. For more information about vaccination in India, click here.