>> VIRUSES.

THESE MICROSCOPIC BEINGS CAN MAKE YOU REALLY SICK OR COULD BE THE HOPE FOR TREATING DISEASE.

WHAT MAKES SOMETHING SO SMALL SO POWERFUL?

STAY TUNED.

THE SCIENTISTS WHO KNOW ARE HERE TO ANSWER YOUR QUESTIONS ABOUT VIRUSES.

"DIALOGUE FOR KIDS" IS NEXT.

>> HELLO, I'M JOAN CARTAN-HANSEN.

THANKS FOR JOINING US HERE ON IDAHO PUBLIC TELEVISION AND ON THE WORLDWIDE WEB.

I DON'T KNOW ABOUT YOU, BUT I'M JUST GETTING OVER A COLD.

A COLD CAN MAKE YOU FEEL REALLY AWFUL.

SO WHAT MAKES US SICK?

THE ANSWER IS A VIRUS.

VIRUSES ARE LITTLE GLOPS OF CHEMICALS THAT USE OTHER ORGANISMS TO MAKE COPIES OF THEMSELVES.

THEY'RE SO SMALL, TOO SMALL TO BE SEEN WITH THE NAKED EYE.

SCIENTISTS HAVE TO USE SPECIAL MICROSCOPES TO EVEN STUDY THEM.

VIRUSES EXIST EVERYWHERE, EVEN IN SPACE.

THEY CAN HANG AROUND FOR YEARS WITHOUT DOING ANYTHING AT ALL, UNTIL THE RIGHT HOST COMES ALONG.

A HOST IS A PLANT OR ANIMAL, OR A LIVING THING.

VIRUSES ARE TRANSMITTED IN DIFFERENT WAYS.

SOME TRAVEL THROUGH THE AIR INTO THE MOUTH AND NOSE.

OTHERS ARE TRANSMITTED THROUGH BODY FLUIDS OR BREAKS IN THE SKIN.

YOU CAN GET A VIRUS FROM A MOSQUITO OR OTHER BUG BITE.

ONCE INSIDE THE HOST BODY, A VIRUS ATTACHES ITSELF TO A CELL WALL.

AND THEN THE BATTLE BEGINS.

THE VIRUS'S OUTER SHELL HAS A SPECIAL SPECIFICALLY SHAPED PROTEIN COATING THAT ALLOWS THE VIRUS TO ATTACH ITSELF TO THE CELL.

IT THEN ATTACKS THE CELL, BURROWING INSIDE AND USES THAT CELL TO MAKE COPIES OF ITSELF.

THE ORIGINAL HOST CELL GENERALLY DIES AND THE MULTIPLYING VIRUS SEEKS OUT NEW CELLS TO ATTACK.

AND THAT CAN MAKE YOU SICK.

SCIENTISTS HAVE FOUND EVIDENCE OF VIRUS-CAUSED ILLNESSES IN THE MUMMIES OF ANCIENT EGYPTIANS.

THE BUBONIC OR BLACK PLAGUE KILLED MILLIONS OF PEOPLE IN THE MIDDLE AGES, AND TODAY WE KNOW A LOT MORE ABOUT HOW VIRUSES MAKE US SICK.

WHEN A VIRUS ENTERS THE BODY, T-CELLS, OR WHITE BLOOD CELLS IN THE BLOODSTREAM, IDENTIFY IT.

AND THAT ALERTS YOUR BODY'S IMMUNE SYSTEM.

YOUR BODY THEN CREATES ANTIBODIES, CHEMICALS DESIGNED TO RECOGNIZE THE SPECIFIC PROTEIN COATINGS OF THE INVADING VIRUS, AND THEN THE ANTIBODIES ATTACK THE VIRUS.

A FEVER IS ONE SIGN THAT YOUR BODY IS FIGHTING OFF AN INFECTION.

YOUR BODY KEEPS A PROTEIN RECORD OF INVADING VIRUSES, SO IF ONE EVER ATTACKS YOU AGAIN, YOUR DEFENSES ARE READY TO FIGHT.

THAT'S CALLED IMMUNITY.

YOU CAN ALSO GET IMMUNITY FROM A VACCINATION.

THAT'S A SHOT CONTAINING A SMALL AMOUNT OF A DEAD OR WEAKENED VERSION OF A VIRUS.

THAT WAY YOUR BODY IS READY TO PROTECT ITSELF FROM THAT DISEASE.

MOST OF US HAVE BEEN VACCINATED AGAINST A NUMBER OF DISEASE THAT'S ONCE KILLED THOUSANDS.

WE'VE EVEN ELIMINATED ONE DISEASE FROM THE EARTH, THAT'S SMALL POX.

POLIO, A DISEASE THAT CAN PARALYZE OR KILL ITS VICTIMS, IS NEXT FOR ELIMINATION, THANKS TO WORLDWIDE EFFORTS BY GROUPS LIKE ROTARY INTERNATIONAL.

BUT WE CAN'T STOP ALL VIRUSES.

VIRUSES CONSTANTLY CHANGE THEIR PROTEIN COATING.

THAT'S CALLED MUTATING.

AND EACH TIME A VIRUS MUTATES, YOU HAVE TO DEVELOP NEW ANTIBODIES TO FIGHT IT.

AND ONCE YOU GET A VIRUS, THERE ISN'T MUCH OF A DOCTOR CAN DO EXCEPT TREAT THE SYMPTOMS.

YOUR BODY'S IMMUNE SYSTEM JUST HAS TO DO THE WORK.

AND THAT'S WHY IT'S IMPORTAN TO PREVENT SPREADING VIRUSES FIRST.

SO BE SURE TO COVER YOUR MOUTH OR NOSE WHEN YOU SNEEZE OR COUGH.

WASH YOUR HANDS FREQUENTLY, ESPECIALLY AFTER GOING TO THE BATHROOM OR BEFORE EATING.

AND KEEP YOUR IMMUNIZATIONS UP TO DATE.

AND IF YOU'RE SICK, STAY AWAY FROM OTHERS UNTIL YOU'RE FEELING BETTER TO REDUCE THE SPREAD OF DISEASE.

SOME SIMPLE STEPS WILL KEEP YOU HEALTHY AND KEEP VIRUSES AT BAY.

AND JOINING ME NOW TO ANSWER YOUR QUESTIONS ABOUT VIRUSES ARE TWO SCIENTISTS.

IN OUR MOSCO BUREAU IS JACOB HORNBY, ASSISTANT PROFESSOR OF BIOLOGY IN THE DIVISION OF NATURAL SCIENCES AND MATHEMATICS AT LEWIS AND CLARK STATE COLLEGE LEWISTON.

THANK YOU FOR JOINING US.

>> THANKS FOR HAVING ME.

>> ALSO IN OUR BOISE STUDIO IS DR.

CHRISTINE HAHN, IDAHO STATE'S EPIDEMIOLOGIST.

AND WE WA TO HEAR FROM YOU.

GIVE US A CALL AT 1-800-973-9800.

OR YOU CAN EMAIL ME AT "D4K" AT -- AT D4K@IDAHOPTV.ORG.

WHEN YOU SEND IN A QUESTION, YOU AND YOUR CLASS WILL HAVE A CHANCE TO WIN A D.V.D.

PLAYER AND OTHER PRIZES.

LET ME ASK YOU, WHAT IS AN EPIDEMIOLOGIST?

>> EPIDEMIOLOGIST, THAT WORD IS RELATED TO OUR WORD FOR EPIDEMIC, OR AN OUTBREAK.

SO EPIDEMIOLOGISTS STUDY DISEASE AND HOW THEY CAUSE OUTBREAKS AND OTHER HEALTH PROBLEMS.

>> AND YOU STARTED YOUR CAREER AS A MEDICAL DOCTOR?

>> YES.

I WENT TO MEDICAL SCHOOL, TRAINED IN MEDICINE, BUT I LOVE PUBLIC HEALTH SO MUCH I TOOK THIS JOB IN EPIDEMIOLOGY BECAUSE I -- INSTEAD OF TREATING THE INDIVIDUAL PATIENT I LIKE TREATING THE WHOLE POPULATION, IF IT WERE, TRYING TO CONTROL DISEASES AND HOW IT SPREADS.

>> AND PROFESSOR HORNBY, YOU'RE A PROFESSOR OF BIOLOGY, WHAT WORK DO YOU DO WITH VIRUSES?

>> I'M BASICALLY A GENERAL MICROBIOLOGIST.

>> LET'S GO TO OUR FIRST CALLER.

SKYLER IN ST.

ANTHONY, ARE YOU THERE?

>> Caller: YES.

>> WHAT'YOUR QUESTION?

>> Caller: HOW DOES A VIRUS START?

>> HOW DOES A VIRUS START?

HOW DOES IT START GET TO INFECT SOMEWYNN, OR HOW DO YOU MEAN?

>> Caller: HOW DOES IT GET ON TO THE EARTH?

>> WHERE DID IT COME FROM?

OK.

LET'S SEE, HOW -- LET'S GO BACK TO THE VERY BEGINNING.

THANK YOU.

>> I CAN GO AHEAD AND TAKE A SHOT AT THAT ONE.

>> OK.

>> AS FAR AS WHERE VIRUSES ORIGINATED FROM, WHERE THEY FIRST STARTED, NUMBER ONE, IT'S A GREAT QUESTION BECAUSE NOBODY KNOWS THE ANSWER TO THAT.

MOST LIKELY VIRUSES HAVE BEEN AROUND AS LONG AS ANY TYPE OF CELL HAS BEEN AROUND.

BUT VIRUSES LIKE -- UNLIKE OTHER CELLS, DON'T LEAVE A FOSSILIZED RECORD, SO WE CAN'T REALLY TRACK WHERE THEY FIRST ORIGINATED, BUT MOST LIKELY THEY STARTED WHEN CELLS BEGAN TO APPEAR, AND WE HAVE FOUND NEW VIRUSES ALL THE TIME WITH DIFFERENT CELL TYPES, AND THEY SEEM TO COME FROM THAT POPULATION.

>> OUR FIRST EMAIL QUESTION CAME IN FROM MRS.

WELLS' CLASS, FOURTH GRADE CLASS, MALLORY WANTS TO KNOW WHAT'S THE DIFFERENCE BETWEEN A VIRUS AND BACTERIA?

>> BOTH VIRUS AND BACTERIA ARE GERMS, OF COURSE, AND THEY CAN BOTH MAKE YOU SICK.

AND VIRUSES, THOUGH, ARE MUCH SMALLER AND MUCH SIMPLER THAN BACTERIA.

BACTERIA ARE PRETTY COMPLEX LITTLE CELLS, AND THEY HAVE A LOT OF INTRICATE STRUCTURES, AND VIRUSES YOU CAN THINK ABOUT THEM AS A VERY SUPER SIMPLE LITTLE OUTFIT, USUALLY A SHELL AND WITH SOME GENETIC INFORMATION INSIDE.

>> LET'S SEE, AN EMAIL FROM CATHY RANKIN'S CLASS, COLTON, HUGO, JOE, AND WANTS TO KNOW HOW A VIRUS GETS INTO YOUR BODY.

>> I CAN TRY THAT.

>> GO AHEAD.

>> I'LL TRY THAT.

IT'S REALLY USUALLY THROUGH THE NOSE OR MOUTH, OR SOMETIMES THROUGH BREAKS IN THE SKIN, SUCH AS A MOSQUITO BITE.

I REALLY LIKE THE EXAMPLES THAT WERE SHOWN IN THE VIDEO, REALLY FOR MOST OF US IT'S THROUGH THE MOUTH OR THROUGH EVEN RUBBING YOUR EYES, THAT TYPE OF THING.

THE VIRUS LIKES THOSE SOFT SURFACES AND IT CAN BURROW IN THAT WAY.

I DON'T KNOW IF YOU HAD ANYTHING ELSE THAT YOU'RE -- >> THE ONLY THING, YOU SAID IT VERY WELL, THAT THROUGH EITHER THE BREATHING IN OR INGESTING BY EATING FOOD THAT'S BEEN IMPROPERLY HANDLED, OR SOME LINE LIKE THAT.

>> LET'S GO TO OUR NEXT CALLER, AUBREY IN HALEY.

>> Caller: MY QUESTION IS, HOW DO YOU GET RID OF A VIRUS?

>> HOW DO YOU GET RID OF A VIRUS?

GOOD QUESTION.

>> HOW TO GET RID OF A VIRUS, OFTEN TIMES YOUR OWN IMMUNE SYSTEM, SO YOUR OWN BODY WILL GET RID OF A VIRUS THAT IS TRYING TO INFECT YOU OR INFECT YOURSELVES.

WE HAVE A VERY, VERY EFFECTIVE DEFENSE AGAINST VIRUSES THERE.

ARE SOME VIRUSES THAT TAKE A LITTLE BIT MORE AND ACTUALLY REQUIRE MEDICATION, OR IN SOME CASES WE HAVEN'T FOUND A WAY TO GET RID OF CERTAIN VIRUSES.

SO THEY MAY STAY WITH YOU FOR THE REST OF YOUR LIFE.

THINGS LIKE COLD SORES OR CANKER SORES WOULD STAY WITH YOU FOR THE REST OF YOUR LIFE.

>> WE HAVE BEEN ABLE TO ERADICATE SMALL POX.

HOW DID WE DO THAT?

>> THAT -- COMPARED TO SOME OF THE OTHER VIRUSES IT WAS A LITTLE EASIER TO GET RID OF.

ONE REASON, THERE'S A VACCINE THAT'S VERY EFFECTIVE, SO YOUNG KIDS PROBABLY NEVER GOT THIS SHOT, BUT IF THEY LOOK AT THEIR PARENTS' ARMS THEY CAN SHOW YOU A SCAR, BECAUSE IT'S REALLY A VACCINE THAT CAUSE AS BIG SCAR.

SO THAT WAS A VERY KEY.

SECONDLY, SMALL POX DOESN'T LIVEOUT SIDE A HUMAN SO YOU DON'T HAVE AN ANIMAL HOST OR PLACE TO FIND IT AND GET RID OF IT TOO, WHERE OTHER VIRUSES ES, LIKE WEST NILE VIRUS, WHERE BIRDS CAN GET IT, MOSQUITOES CARRY IT, THAT'S GOING TO BE A BIGGER CHALLENGE.

>> HOW ABOUT POLIO?

WILL WE EVER BE ABLE TO ERADICATE POLIO?

>> AS YOU MENTION IN THE INTRODUCTION, POLIO IS CERTAINLY ON THE RADAR SCREEN AS SOMETHING THAT COULD BE ELIMINATED, THERE IS A VACCINE, IT'S VERY EFFECTIVE, AND ALSO IT TENDS TO LIVE ONLY IN HUMANS.

IT'S NOT ONE THAT HAS A LOT OF ANIMAL HOSTS OR OTHER THINGS.

BUT IT'S BEEN VERY CHALLENGING, AND RECENTLY THE WORLD HAS BEEN STRUGGLING TO TRY GET RID OF POLIO, PARTLY BECAUSE OF WARS AND CONFLICTS AROUND THE WORLD, IT'S BEEN HARD FOR HEALTH WORKERS TO GET ALL THE KIDS VACCINATED.

SO THIS VIRUS IS STILL OUT THERE, UNFORTUNATELY, AND THAT'S ONE REASON WHY KIDS TODAY ARE STILL GETTING THE POLIO SHOTS AS PART OF THEIR ROUTINE SHOTS WHEN THEY GO TO SCHOOL.

>> A QUESTION FROM MRS.

HAGER'S THIRD GRADE CLASS IN GRANGEVILLE, SAVANNAH AND BRANDON WANT TO KNOW HOW GERMS MAKE YOU SICK.

HOW DOES THAT VIRUS GET INTO YOUR BODY AND MAKE YOU SICK?

>> AGAIN, A COUPLE DIFFERENT REASONS.

SOME VIRUSES WILL ACTUALLY CAUSE DAMAGE TO YOUR OWN CELLS, AND SO WE'LL END UP LEADING TO ILLNESSES LIKE, YOU COULD LOOK AT INFLUENZA, THE FLU VIRUS WILL ACTUALLY CAUSE DAMAGE TO SOME OF YOUR CELLS, AND WILL LEAD TO PROBLEMS ASSOCIATED WITH THAT.

THE OTHER REASONS WHY YOU END UP FEELING SICK WHEN YOU HAVE A VIRAL INFECTION IS BECAUSE OF YOUR BODY TRYING TO DEFEND YOURSELF AGAINST ITSELF.

THE FEVER AND THE RUN AYE NOSE AND THE COUGH AND EVERYTHING LIKE THAT IS ACTUALLY A GOOD THING BECAUSE IT'S TRYING TO GET RID OF THAT VIRUS, AND MAKE YOU HEALTHY AGAIN.

>> ARE THERE ONLY BAD VIRUSES, AND NO GOOD ONES?

>> YES, THERE ARE GOOD VIRUSES.

WE HAVE OUR HUMAN-CENTERED VIEW THAT ANYTHING THAT MAKES US SICK IS A BAD VIRUS, AND THAT'S NOT A BAD PERSPECTIVE TO HAVE, BUT THERE ARE LOTS OF VIRUS THAT'S DON'T INFECT HUMANS.

SOMETIMES THEY INFECT EITHER ANIMALS OR PLANTS, OR THEY INFECT HUMAN AND DON'T MAKE YOU SICK.

SOME PEOPLE CAN -- THERE ARE CERTAIN TYPES OF VIRUS THAT'S PROBABLY DON'T CAUSE A LOT OF ILLNESSES, AND SOME VIRUS THAT'S MAY ACTUALLY BE BENEFICIAL TO WHOEVER HAS IT.

AND SO, YEAH, THEY RUN THE WHOLE GAMUT.

WE TEND TO THINK OF ALL GERMS AS BAD, BUT REALLY THEY AREN'T.

THEY'RE IMPORTANT PARTS OF NATURE.

>> DREW FROM MRS.

KERR'S CLASS WANTS TO KNOW, WHAT'S THE MOST DANGEROUS VIRUS?

>> THE MOST DANGEROUS?

PROBABLY AGRICULTURE USABLE, BUT MOST LIKELY -- ARGUABLE, BUT MOST LIKELY, LIKE EEBOLA VIRUS, WHICH TENDS TO BE VERY DIFFICULT TO CONTROL ONCE IT INFECTS AN INDIVIDUAL, AND ALSO HAS A FAIRLY HIGH MORTALITY RATE AND CAN LEAD TO QUITE A FEW DEATHS.

SO EBOLA VIRUS, OR A RELATED VIRUS THAT'S OUT IN THE WORLD AS WELL.

>> AND I WILL -- >> THAT WOULD BE MY ANSWER.

>> AS JACOB KNOWS, I'M GOING TO THROW IN WHAT I THINK IS A VIRUS THAT'S CLOSER TO HOME FOR MOST OF US, IN IDAHO I DEFINITELY AGREE THAT EBOLA AND MARBURG ARE INCREDIBLY DANGEROUS, BUT RABIES VIRUS, WHICH EXISTS IN IDAHO AND IS MOSTLY IN BATS IN IDAHO, AND IN -- A GOOD REASON TO REMEMBER TO AVOID BATS AND NOT TOUCH THEM IS THAT IF YOU'RE INFECTED WITH THAT VIRUS, IT IS ALMOST, ALMOST ALWAYS LEAD TO DEATH.

SO IT'S A REALLY NASTY VIRUS IF YOU GET INFECTED.

>> AND NOT TREATED.

>> FORTUNATELY IF YOU GET BITTEN YOU CAN GET SHOTS AND PREVENT GETTING SICK.

BUT ONCE PEOPLE GET SICK WITH THIS VIRUS IT'S A REALLY NASTY ONE.

>> IT'S A VERY PAINFUL SERIES OF SHOTS.

>> IT USED TO BE THERE.

ARE NEW SHOTS AND IT'S NOT AS BAD.

WHEN I WAS IN KID WE LIVED IN FEAR OF GETTING THE SHOTS.

BUT IT'S NOT SO BAD ANYMORE.

>> LET'S GO TO FAITH.

>> Caller: HOW DOES A PERSON GET -- HOW DOES THE FIRST PERSON GET A VIRUS?

>> I'LL TAKE A SHOT AT THAT.

AGAIN, WE DON'T REALLY KNOW HOW THAT FIRST PERSON GOT A VIRUS, BUT IT IS VERY LIKELY THAT IT PROBABLY GOT IT FROM AN ANIMAL.

BECAUSE A VIRUS IS AS JACOB MENTIONED EARLIER IN THE PROGRAM, VIRUSES HAVE PROBABLY BEEN AROUND AS LONG AS THERE HAVE BEEN LIVING BEINGS, PROBABLY LONGER THAN HUMANS HAVE BEEN AROUND.

SO ONCE HUMANS CAME AROUND, THEY PROBABLY GOT THEIR FIRST INFECTIONS FROM, LET'S SAY, THEIR PET DOG, OR MAYBE A BIRD.

WE JUST TALKED ABOUT WEST NILE VIRUS AND HOW YOU CAN GET IT FROM MOSQUITOES, ETC.

SO IT'S PROBABLY HOW IT FIRST JUMPED INTO HUMANS, WAS FROM SOME ANIMAL OR ANOTHER.

>> LET'S GO TO MIRANDA IN PULLMAN.

>> Caller: HOW ARE VIRUSES DISCOVERED?

>> HOW DID THEY DISCOVER VIRUSES?

>> I CAN ANSWER THAT ONE.

AS FAR AS WHEN THE VIRUSES WE FIRST DISCOVERED, FIRST OF ALL, PEOPLE KNEW OF DISEASES THAT WERE -- WE WILL EVENTUALLY FIND OUT AS BEING FROM A VIRUS FOR MANY HUNDREDS OF YEARS, ALL THE WAY BACK TO WHEN SMALL POX WAS IDENTIFIED AS FAR AS A DISEASE.

BUT WHEN VIRUS WERE FIRST IDENTIFIED, AND ACTUALLY THE TERM VIRUS WAS FIRST USED, THAT WAS ABOUT IN THE LATE 1800S, SO PROBABLY OVER A HUNDRED YEARS AGO.

TWO PEOPLE WERE LOOKING AT A VIRUS THAT WAS INFECTING A PLANT, INFECTING THE TOBACCO PLANT, AND FOUND THAT IF YOU TRIED TO FILTER A SOLUTION THAT CAME FROM THAT PLANT, YOU COULD STILL INFECT ANOTHER PLANT AND CAUSE IT TO GET THE SAME DISEASE, AND WE'RE ABLE TO SHOW THAT FIRST OF ALL BACTERIA WOULD BE FILTERED, AND ELIMINATED, BUT THE VIRUS CAN ACTUALLY GET THROUGH THAT FILTER.

AND THAT CAME TO ALLOW US TO FIRST KNOW, I GUESS FIRST UNDERSTAND A VIRUS AS THE TOBACCO MOSAIC VIRUS THAT INFECTED A PLANT, AND THE WORD "VIRUS" IS USED AS A LATIN WORD FOR POISON.

SO THAT'S WHAT WAS FIRST USED TO DESCRIBE THIS.

>> LET'S GO TO BYRON -- EXCUSE ME, BRYAN IN COEUR D'ALENE.

>> Caller: YEAH?

>> GO AHEAD.

YOU'RE ON THE AIR.

GO AHEAD.

>> Caller: WHY DO VIRUSES COPY THEMSELVES?

>> OK.

WHY DO THEY MAKE COPIES OF THEMSELVES?

>> WELL, VIRUSES EVEN THOUGH WE CAN DISCUSS WHETHER THEY'RE REALLY LIVING CREATURES LIKE BACTERIA AND ANIMALS AND PLANTS, THEY ARE DRIVEN GENETICALLY IN THE SAME WAY THAT PEOPLE AND ANIMALS ARE DRIVEN TO HAVE KIDS AND TO REPRODUCE THEMSELVES.

SO IT'S REALLY NO DIFFERENT IN THAT THE VIRUS EXISTENCE, A BIG PART OF IT, IF THEY DIDN'T MAKE COPIES OFTHEMSELVES, THEY WOULD EVENTUALLY BE BROKEN DOWN, MAYBE FALL APART, AND THEY WOULD GO AWAY.

SO IF THEY'RE STILL AROUND IT'S ONLY BECAUSE THEY'VE MANAGED TO KEEP MAKING COPIES OF THEMSELVES AND GO OUT AND MAKE MORE COPIES.

IT'S SORT OF A FIGHT FOR SURVIVAL.

>> TRISTAN FROM POT LATCH, THIS IS -- WHAT DO VIRUSES FEED ON?

>> WHAT DO THEY FEED ON?

BASICALLY AS CHRISTINE JUST MENTIONED, THE MAJOR GOAL FOR A VIRUS IS TO KEEP ON GOING AND MAKE MORE THEMSELVES.

SO AS FAR AS WHAT DO THEY EAT, THEY REALLY DON'T EAT ANYTHING.

THEY INFECT OR ENTER INTO A CELL THAT WE WOULD CALL A HOST CELL, AND THEN THEY BASICALLY USE PROTEINS AND VARIOUS PARTS OF THAT HOST CELL TO MAKE COPIES OF THEMSELVES.

TO MAKE COPIES OF THE VIRUS.

AND THEN THEY WILL LEAVE THAT CELL AND GO FIND MORE CELLS TO INVADE AND INFECT.

SO THEY REALLY DON'T EAT ANYTHING TO CONTINUE ON, THEY JUST SIMPLY ENTER A CELL, MAKE COPIES, AND THEN LEAVE THAT CELL.

>> LET'S GO TO RACHEL IN CALDWELL.

RACHEL?

>> Caller: WHY ARE SCIENTISTS NOT SURE WHETHER A VIRUS IS A LIVING THING?

>> IS A VIRUS A LIVING THING OR NOT?

THAT'S A VERY GOOD QUESTION.

>> I THINK WHAT YOU GET INTO, I THINK YOU PROBABLY HEARD THIS DISCUSSION, THERE ARE AREAS AS WELL, IT REALLY BOILS DOWN TO, WHAT IS LIFE?

WHAT DOES IT MEAN TO BE ALIVE, AND THAT'S NOT REALLY A PURELY SCIENTIFIC QUESTION, THAT'S ALSO A PHILOSOPHICAL QUESTION.

PEOPLE HAVE DIFFERENT OPINIONS ABOUT THAT, ABOUT WHAT EXACTLY IS LIFE.

I THINK FOR VIRUSES, I THINK BOTH JACOB AND I FEEL LIKE WE DON'T -- THEY DON'T MEET WHAT WE THINK IS WHAT MANY SCIENTISTS FEEL ARE NECESSARY MINIMUM CRITERIA FOR LIFE, BUT THERE ARE OTHER PEOPLE THAT WOULD SAY NO, IT CAN MAKE COPIES OF ITSELF, IT CAN DO THIS AND THAT, AND FOR ME THAT MEANS IT'S ALIVE.

SO I THINK THAT'S ONE THING THAT'S FUN AND EXCITING ABOUT SCIENTISTS, NOT -- IT'S NOT ALL CUT AND DRY.

THERE'S ROOM FOR ARGUMENT, ROOM FOR MORE STUDY.

>> I'LL TOSS THE LIVING QUESTION UP TO YOU TOO.

>> OK.

>> WHAT DO YOU THINK?

>> I'D AGREE WITH THE -- DR.

HAHN'S COMMENTS AS WELL, THAT DEBATING WHETHER OR NOT A VIRUS IS LIVING OR NOT IS ONGOING AND PROBABLY WILL CONTINUE FOR AS LONG AS WE CAN KEEP DEBATING EACH OTHER.

WHY SCIENTISTS CAN'T COME TO A CONCLUSION ON THIS IS BECAUSE WE LOVE TO ARGUE WITH EACH OTHER.

WE -- [LAUGHTER] WE DON'T LIKE TO SETTLE ON SOMETHING IF WE REALLY DON'T BELIEVE IN IT, SO -- AND WE USE DATA, WE USE EVIDENCE TO SUGGEST ONE WAY OR ANOTHER, AND THE -- AS CHRISTINE SAID, ONE OF THE BEST PARTS ABOUT BEING A SCIENTIST IS CONTINUALLY QUESTIONING EVEN INFORMATION THAT WE FEEL IS WELL ESTABLISHED ESTABLISHED, THAT IT'S VERY ENJOYABLE TO CONTINUE TO QUESTION IT AND CONTINUE TO LOOK AT THOSE TOPICS.

SO WHETHER A VIRUS IS LIVING OR NOT, AS I WAS TALKING BEFORE THIS SHOW, I POSE THIS QUESTION TO MY FIRST YEAR BIOLOGY CLASS EVERY YEAR, AND WE NEVER COME TO A CONCLUSION ON IT.

I HAVE MY BELIEFS, BUT THERE ARE OTHERS WHO HAVE DIFFERENT UNDERSTANDINGS OR OPINIONS ON IT.

>> LET'S GO TO CADEN.

>> Caller: BARRING TOYS OR TRADING SOMETHING -- COULD BORROWING TOYS OR TRADING SOMETHING GIVE YOU A COLD?

>> CAN YOU GET A COLD BY HANDLING OTHER PEOPLE'S THINGS?

>> YES, YOU CAN.

THERE ARE -- YOU KNOW, WE DON'T WANT PEOPLE TO BE AFRAID TO PLAY WITH THEIR FWRENDZ AND THINGS LIKE THAT, BUT IT'S A GOOD REMINDER THAT THESE -- SOME OF THESE VIRUSES DO SURVIVE, AT LEAST FOR SHORT PERIODS OF TIME ON THINGS.

YOUR TOYS, YOUR SURFACES, LIKE TABLES AND THINGS LIKE THAT.

SO IT'S JUST A GOOD REMINDER THAT FIRST OF ALL IF YOU'RE SICK, TO TRY NOT TO EXPOSE OTHER PEOPLE BY WASHING YOUR HANDS FREQUENTLY, USING A KLEENEX TO SNEEZE INTO, THAT TYPE OF THING, SO YOU ARE NOT SPREADING THOSE GERMS AROUND.

AND ALSO A REMINDER THAT DURING FLU SEASON, DURING COLD SEASON, BE ESPECIALLY CAREFUL ABOUT WASHING YOUR HANDS A LOT.

BUT IT'S IMPOSSIBLE TO COMPLETELY AVOID ALL VIRUSES, AND STILL LIVE A NORMAL LIFE.

>> COREY WANTS TO KNOW WHY ISN'T THERE A CURE FOR THE DISMOALD YOU MAKE A LOT OF MONEY IF YOU CAN FIGURE OUT A CURE FOR THE COLD.

>> I CAN START TO ANSWER THAT.

I CAN CHIME IN ON THAT ONE.

ONE OF THE MAJOR REASONS WHY THERE ISN'T A REAL CURE FOR THE COLD, NUMBER ONE, THERE'S A LARGE NUMBER OF DIFFERENT TYPES OF VIRUSES THAT ACTUALLY CAUSE WHAT WE CALL THE COMMON COLD.

THE MOST COMMON ONE GOES BY THE NAME OF RHINO VIRUS, BUT THERE ARE MANY OTHER TYPES OF VIRUS THAT'S DO CAUSE THE COLD.

WHEN WE LOOK AT THE RHINO VIRUS, THE ONES THAT CAUSE THE MOST COMMON TYPES OF COLDS, ONE OF THE PROBLEMS WE HAVE IS THAT AS THEY INFECT A CELL THEY HAVE -- THEY CAUSE ERRORS WHEN THEY COPY THEMSELVES.

WHEN THEY LEAVE THE CELL THEY ACTUALLY LEAVE A LITTLE BIT DIFFERENT THAN THEY ENTERED.

AND SO YOUR BODY HAS A DIFFICULT TIME REMEMBERING OR RECOGNIZING THAT VIRUS OR THE DIFFERENT VIRUS THAT'S WILL END UP COMING OUT OF DIFFERENT PEOPLE.

SO THEY'RE CONSTANTLY CHANGING, AND THE OTHER THING IS THAT WE DON'T HAVE A VERY GOOD MEMORY FOR RHINO VIKINGS FOR THE COLD BECAUSE THEY DON'T REALLY CAUSE AN INCREDIBLY SUBSTANTIAL INFECTION, SO WE DON'T HAVE A TENDENCY TO REMEMBER THOSE AS WELL.

>> BECKY FROM JEROME WANTS TO KNOW WHAT -- HOW DID WE FIND THE FIRST VACCINE FOR VIRUSES?

THE FLU VIRUS, THERE'S AN INTERESTING PROCESS IN MAKING -- >> I'M TRYING TO THINK THE BEST I CAN WHAT THE VERY FIRST FLU -- VIRAL VACCINE WAS, AND I'M NOT QUITE SURE OFFHAND.

SMALL POX IS PROBABLY IT.

AND THAT ONE IS A REALLY INTERESTING STORY.

IT WAS A VERY BRAVE EXPERIMENT, REALLY ON THE PART OF A LITTLE BOY WHO AGREED WHAT HAPPENED WAS THERE'S A SIMILAR DISEASE TO SMALL POX CALLED COWPOX, AND IN THE COW -- THE COWS CARRIED THIS VIRUS, AND IT WAS NOTICED THAT MILK MAIDS, GIRLS THAT YOUNG LADIES THAT WORKED AROUND COWS A LOT DIDN'T TEND TO GET SMALL POX AS MUCH, AT LEAST THAT WAS THE THEORY.

YOU ALWAYS HEARD THAT TERM "PRETTY AS MILK MAID," THEIR PHASES WEREN'T SCARRED FROM SMALL POX.

SO BASED ON THAT THEY TRIED TAKING A LITTLE BOY AND PURPOSELY GIVING HIM COWPOX.

AND IT TURNED OUT -- AND THEN THEY CHALLENGED HIM BY EXPOSING HIM TO SMOG.

I CAN'T -- SMALL POX.

I CAN'T IMAGINE WHAT MOTHER AGREED TO THAT.

BUT THE LITTLE BOY SURVIVED AND DID JUST FINE.

SO THAT WAS A HUGE STEP FORWARD IN PROVING THAT IF YOU GOT EXPOSED TO ONE VIRUS OR SOMETHING CLOSE TO WHAT THE DISEASE THAT YOUR BODY COULD BUILD UP THIS IMMUNITY AND THEN YOU WOULDN'T GET SICK.

SO IT WAS A REALLY INTERESTING STORY, AND REALLY A HUGE LEAP FORWARD FOR VACCINE DEVELOPMENT WHEN THEY TRIED THAT EXPERIMENT.

>> OK.

>> I COULD ADD TO THAT TOO.

IN -- PRIOR TO THAT AS WELL, AT DR.

THE DOCTOR FAULKED ABOUT THE FIRST ACTUAL USE OF WHAT WE CALL VACCINATIONS, OR VACCINE, ABOUT I WOULD SAY MAYBE 60 OR 70 YEARS BEFORE THAT, THIS IS IN THE EARLY 1700'S, THERE WAS A WOMAN BY THE NAME OF MARY MONTEGUETHAT WAS A WRITER FROM ENGLAND, WHO HER HUSBAND WAS AN AMBASSADOR, I BELIEVE, TO WHAT IS NOW TURKEY, AND SHE ACTUALLY HAD SMALL POX AND W TERRLY SCARRED FROM IT.

AND SHE SAW THAT THE LOCAL WOMEN WERE DOING SOMETHING CALLED ENGRAFTING, WHERE THEY WOULD TAKE FLUIDS FROM A PERSON WHO HAD SMALL POX AND A CERTAIN TYPE OF SMALL POX, ACTUALLY, THE ONE THAT ISN'T AS DEADLY, OR DAMAGING, CALLED -- >> WE'RE ALMOST OUT OF TIME.

>> OK.

AND INFECTED OTHER INDIVIDUALS, AND THEN SHE WANTED TO DO THAT ON HER OWN SON TO PROTECT HIM FROM WHAT SHE HAD.

>> FOR THE FOLKS WHO ARE STILL ONLINE, HANG ONLINE, BECAUSE WE'LL BE TAPING OUR WEB-ONLY, WEB EXTRA EFFORT, SO HANG IN, WE'LL GET TO YOUR QUESTIONS.

WE'VE RUN OUT OF TIME FOR THIS BROADCAST PROGRAM.

I'D LIKE TO THANK OUR GUESTS, THANK YOU BOTH FOR BEING HERE.

I APPRECIATE IT.

IF YOU DIDN'T GET YOUR QUESTIONS ANSWERED, GO TO IDAHOPTV.ORG.

THAT WEB-ONLY PROGRAM WILL BE THERE, ONE YOU CAN SEE ONLY ON THE WEB.

AND THERE OUR EXPERTS WILL ANSWER MORE QUESTIONS.

THERE'S ALSO LOTS OF LINKS AND MORE INFORMATION ABOUT VIRUS AND MANY OTHER TOPICS.

CHECK IT OUT AT IDAHOPTV.ORG.

AND CLICK ON "D4K," "DIALOGUE FOR KIDS."

IN OUR NEXT BROADCAST PROGRAM, WE'LL HAVE A SPECIAL PROGRAM CALLED "SIMPLE EXPERIMENTS."

WE HAVE TWO SCIENTISTS COMING ON WHO WILL SHOW SMUS BASIC EXPERIMENT THAT'S ILLUSTRATE SOME BASIC SCIENTIFIC PRINCIPLES, AND I THINK EXPLOSIONS MIGHT BE INVOLVED.

IT'S ALWAYS ON SPECIAL DATE, DECEMBER 12, THE SECOND TUESDAY RATHER THAN OUR USUAL THIRD TUESDAY SLOT, SO JOIN US DETECTIVE 12 AT OUR REGULAR TIME.

2:00 P.M.

MOUNTAIN, 1:00 P.M.

PACIFIC, AND SEND IN YR QUESTIONS.

THIS MONTH'S WINNER OF THE CONTEST WAS GORDON FROM MRS.

WALTON AND MRS.

ALLEN'S CLASS FROM A.H.

BUSH ELEMENTARY IN IDAHO FALLS.

REMEMBER, WHEN YOU SEND IN THAT QUESTION, YOU AND YOUR CLASS ARE ELIGIBLE TO WIN IN OUR CONTES CHECK US OUT ON THE WEB AND WE'LL SEE YOU NEXT TIME HERE ON "D4K," "DIALOGUE FOR KIDS."

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