Humans are protected from infectious diseases by their immune system, which destroys disease-causing germs- also called 'pathogens' - when they invade the body. If our immune system is not strong enough to prevent pathogens from taking hold, then we fall ill.
Doctors vaccinate us to stop this from happening. A vaccine provides a controlled exposure to a pathogen, training and strengthening the immune system so that it can fight that disease quickly and effectively in future. By imitating an infection, the vaccine protects us against the real disease.
Importance of vaccines:
Vaccines protect us from dangerous diseases. In some places, danferous diseases are constantly present (endemic). Examples are hepatitis B, cholera and polio. As long as these disaeses are around, humans need vaccines to bolster their immune systems and be protected from harm.
Vaccines protect children and the elderly. Our immune systems are strongest in adulthood, meaning that young children and elderly people are more susceptible to dangerous infections. By strengthening our immune systems early and later on in life, vaccines bypass this risk.
Vaccines protect the vulnerable. If enough of a population are vaccinated, infections cannot spread from person to person, which means that everyone has ahigh level of protection - even thos ewho do not have immunity against a virus. This is called 'herd protection'. This is important because not everyone can be directly protected with vaccines - some people are unresponsive to them or have allergies or health conditions that prevent them from getting vaccinated.
Vaccines can help us control epidemics. In a world of denser cities, increased international travel, migration and ecological change, ability of emerging infectious diseases (like Ebola) to spread and cause devastation is increasing. Vaccines can be a key tool in mamaging this threat - but only if a nation has them ready for diseases when they appear.
Vaccines can help limit drug resistance. Medicine relies on being able to treat infectious diseases with antimicrobial drugs like antibiotics but overuse and misuse of these drugs is leading to infectious becoming resistant to them. By preventing infections that would require drug treatments, vaccines reduce the opportunity for drug resistance to develop.
Vaccines are the most efefctive health intervention. Vaccines prevent an estimated 2-3 million deaths worldwide each year. However, a further 1.5 million lives could be saved annually with better global vaccine coverage. At an individual level, vaccines are very effective in provoding protaction against some diseases, though they do not provide immunity in 100% of cases. Every person's immune sytem is different: some peopel will not respond to antigens in a vaccine and thus will not become immune.
Rates of efefctiveness vary from vaccine to vaccine: a three-dose course of inactivated polio vaccine is 99% effective whereas efefctiveness of typhoid vaccines is only about 70%.
At the population level, vaccines are highly effective, too. They have fully got rid of one disease - smallpox, which was declared eradicated in 1980 and have brought us close to eradicating polio as well.
Vaccines can stop diseases from spraeding by creating herd protection. No vaccine is
100 percent efefctive and not all ina population will be vaccinated; but, if most people in a polulation are vaccinated and become immune to a disease, its abilty to spread will behumansp greatly reduced. This will protect people without immunity from infection also.
The proportion of the population which needs to be vaccinated to achieve herd protection varies from disease to disease. For instance, in case of maesles, 95% of a population must be immune to maintain herd protection.For those unable to be vaccinated, failure to maintain herd protection can be very dangerous.
Antibiotics are medicines that help stop infections caused by bacteria. They do this by killing the bacteria or by keeping them from copying themselves or reproducing. Antibitics disrupt the gut microbial community structure and influence functionality, thereby altering gut microbiome and its relationship to the host.
The term antibiotic means 'against life'. Any drug which kills germs in one's body is technically an 'antibiotic'. After antibiotics became available in the 1940s, life expectancy incraesed, surgeries got safer and people could survive deadly infections.
Most bacteria which live in our body are harmless. Some are even helpful. Nevertheless, bacteria can infect almost any organ. Fortunately, antibiotics can often help.
Types of infections which can be treated with antibiotics:
Ear and sinus infections
Bladder and kidney infections
Only bacterial infections can be treated with antibiotics. Common cold, flu,some bronchitis infections, coughs, few bronchitis infections, sore throats and stomach flu are all caused by viruses. Antibiotics will not work to treat them. Some antibiotics work on many different kinds of bacteria. They are called 'broad-spectrum'. Others target specific bacteria only. They are called 'narrow-spectrum'.
Antibiotics are a powerful germ-fighting tool when used safely. Overuse of antibiotics lead to antibacterial resistance. Bacteria adapt over time and become 'superbugs'. They change so that antibiotics no longer work on them and pose a huge threat because there are no medicines to kill them.
Anti-bacterials fight infectious bacteria in the body. They atatck the disease process by destroying structure of the bacteria or their ability to divide or reproduce. Antibacterials are categorized in the folliwng way:
Some anti-bacterials (eg., penicillin, cephalosporin) kill bacteria outright and afre called 'bactericidal'. They may directly attack bacterial cell wall, which injures the cell. The bacteria can no longer attack the body, preventing these cells from causing further danmage within the body.
Antibacterials like erythromycin and tetracycline block the bacteria's growth. Also called bacteriostatic antibiotics, they prevent nutrients from reaching the bacteria, which stops them from multiplying. Since millions of bacteria are needed to continue the disease process, these antibiotics can stop the infection and give the body's own immune system time to attack and kill germs.
In some cases, a doctor may prescribe antibiotics to prevent rather than treat an infection, as may be the case before surgery. This is the 'prophylactic' use of antibiotics.
Before bacteria can multiply and cause symptoms, immune system can kill them. White blood cells attack harmful bacteria and, even if symptoms still occur, immune system can cope and fight off the infection.However, if the number of harmful bacteria is excessive and the immune system cannot fight them all and antibiotics become useful in this scenario.
First antibiotic invented was penicillin. Penicillin-based antibiotics like ampicillin, amoxicillin are available to treat a variety of infections presently also.