Dumaguing: Know your vaccines
VACCINES are all over the place lately, not so much for their demand but rather the fear that the Dengvaxia issue has generated so that it is perfectly understandable that there is massive tri-media monitoring of the development of the investigation not only by the Department of Health but also the Department of Justice, and now the Senate.
In the United States, there is an increasing reluctance of parents to have their children vaccinated. It seems that it's only the elderlies are eager to have their flu shots in anticipation of the cold weather brought by old man winter.
Dear readers, friends and patients alike, with your kind indulgence, your columnist would like to share his one-cent worth of thoughts, comments and opinion. Standard textbooks in microbiology and immunology define vaccine as a material that can artificially- not by getting sick- induce immunity to an infectious disease, usually after ingestion of the material(e.g. oral polio vaccine) or thru injection.
In other words, vaccine deliberately, that is, purposely exposes a person to a harmless version of a pathogen- microbes like viruses, bacteria) to stimulate/challenge the person's immune system to produce protective antibodies and memory cells.
In this manner, the person's immune system is primed and prepared to mount a strong protective and defensive antibody response should the same microbe or pathogen be encountered again in the near future.
Various materials are used in vaccines. Most vaccines are made from living or dead (inactivated) pathogens or even from some toxins which the microbes themselves produce.
In general vaccines made from living organisms are most effective but they must be prepared from harmless organisms that are antigenecally closely related to the microbe or from what is called attenuated-weakened- microbe that have been genetically changed so that they are no longer capable of causing the full-blown disease.
Progress in research propelled by a broad background in biochemistry showed that it was practical and found it safe to vaccinate against several diseases by combining specific vaccines in a single injection.
Classic examples are the DTP vaccine which contain toxoids to prevent diphtheria and tetanus and antigenic portions of killed bacteria (Bordatella pertussis) to prevent whooping cough or pertussis. Of course, most mothers know the MMR or the measles-mumps-rubella (German measles) vaccine.
Basic requirements for a vaccine to be called "ideal" include, it must contain enough antigenic determinants to stimulate/challenge the immune system of the person to produce the desired amount of protective antibodies, it must contain antigenic determinants from all strains of the pathogen/microbe that cause the disease- in the case of polio- Leon, Brunhilde, Lansing- such vaccines are called multivalent or polyvalent.
The vaccine has few (preferably, NO) side effects. And most importantly, the vaccine does not cause disease in the vaccinated person.
Allow us to give a dash of historical highlights. The word vaccine comes from “vacca” the latin word for cow and the medical world remembers Edward Jenner, a British physician who volunteered to be immunized by then the so-called Chinese method using powder prepared from dried smallpox scabs- inhaling the powder.
He later noticed that milkmaids working closely with cows never had small pox, thus he hypothesized that having the milder cowpox protected the patients from having the more serious, deforming and fatal small pox. Jenner vaccine, using material from dried cowpox lesions, eradicated smallpox and humanity is eternally grateful