Do you know What’s the difference between a bacterial infection and a viral infection?

Bacteria
Bacteria are single-celled microorganisms that thrive in many different types of environments. Some varieties live in extremes of cold or heat. Others make their home in people’s intestines, where they help digest food. Most bacteria cause no harm to people, but there are exceptions.

Infections caused by bacteria include:
Strep throat
Tuberculosis
Urinary tract infections
Inappropriate use of antibiotics has helped create strains of bacterial disease that are resistant to treatment with different types of antibiotic medications.

Viruses
Viruses are even smaller than bacteria and require living hosts — such as people, plants or animals — to multiply. Otherwise, they can’t survive. When a virus enters your body, it invades some of your cells and takes over the cell machinery, redirecting it to produce the virus.

Diseases caused by viruses include:
Chickenpox
AIDS
Common colds
In some cases, it may be difficult to determine whether a bacterium or a virus is causing your symptoms. Many ailments — such as pneumonia, meningitis and diarrhea — can be caused by either type of microbe.

Childhood vaccines: Tough questions, straight answers
Do vaccines cause autism? Is it OK to skip certain vaccines? Get the facts on these and other common questions.
By Mayo Clinic Staff
Childhood vaccines protect children from a variety of serious or potentially fatal diseases, including diphtheria, measles, meningitis, polio, tetanus and whooping cough. If these diseases seem uncommon — or even unheard of — it’s usually because these vaccines are doing their job.
Still, you may wonder about the benefits and risks of childhood vaccines. Here are straight answers to common questions about childhood vaccines.

Is natural immunity better than vaccination?
A natural infection often provides more complete immunity than a series of vaccinations — but there’s a price to pay for natural immunity. For example, a natural chickenpox (varicella) infection could lead to pneumonia. A natural polio infection could cause permanent paralysis. A natural mumps infection could lead to deafness. A natural Hib infection could result in permanent brain damage. Vaccination can help prevent these diseases and their potentially serious complications.

Do vaccines cause autism?
Vaccines do not cause autism. Despite much controversy on the topic, researchers haven’t found a connection between autism and childhood vaccines. In fact, the original study that ignited the debate years ago has been retracted.
Although signs of autism may appear at about the same time children receive certain vaccines — such as the measles, mumps and rubella (MMR) vaccine — this is simply a coincidence.

Are vaccine side effects dangerous?
Any vaccine can cause side effects. Usually, these side effects are minor — low-grade fever, and soreness, redness or swelling at the injection site. Some vaccines cause a temporary headache, dizziness, fatigue or loss of appetite. Rarely, a child may experience a severe allergic reaction or a neurological side effect, such as a seizure. Although these rare side effects are a concern, vaccines are much safer than the diseases they prevent.
Of course, vaccines aren’t given to children who have known allergies to specific vaccine components. Likewise, if your child develops a life-threatening reaction to a particular vaccine, further doses of that vaccine won’t be given.

Why are vaccines given so early?
Diseases that childhood vaccines are meant to prevent are most likely to occur when a child is very young and the risk of complications is greatest. That makes early vaccination — sometimes beginning shortly after birth — essential. If you postpone vaccines until a child is older, it may be too late.

Is it OK to pick and choose vaccines?
In general, skipping vaccines isn’t a good idea. This can leave your child vulnerable to potentially serious diseases that could otherwise be avoided. And consider this: For some children — including those who can’t receive certain vaccines for medical reasons — the only protection from vaccine-preventable diseases is the immunity of the people around them. If immunization rates drop, vaccine-preventable diseases may once again become common threats.
If you have reservations about particular vaccines, discuss your concerns with your child’s doctor. If your child falls behind the standard vaccines schedule, ask the doctor about catch-up immunizations.

http://www.mayoclinic.org/diseases-conditions/infectious-diseases/expert-answers/infectious-disease/faq-20058098