3 ms·

That's the truly nasty part of this dilemma: we can't stop vaccinating for it. People who haven't been vaccinated are most at risk of being infected due to the

by makomk 7y ago

That's the truly nasty part of this dilemma: we can't stop vaccinating for it. People who haven't been vaccinated are most at risk of being infected due to the polio vaccine, since the vaccine-derived strains spread from person to person just like the wild polio that they almost eliminated and become more dangerous as they do so. In order to keep those infections under control people are being vaccinated on a massive scale, which works in the short term but spreads massive amounts of the vaccine poliovirus which will cause infections further down the line. The injectable polio vaccination might offer a solution since it uses a dead virus that can't cause an actual infection, but there's just not the infrastructure to treat eveyone with it.

gus_massa 7y ago
Read the recomendad schedule by WHO in https://en.wikipedia.org/wiki/Polio_vaccine#Schedule https://en.wikipedia.org/wiki/Polio_vaccine#Schedule * For countries with endemic: case use a few doses of the oral vaccine (that is more powerful) and at least one dose of the injectable version. * For countries without recent cases an a good vaccination coverage: A few injectable doses and later a few oral doses * For countries with very good coverage and low risk of imported cases: Use only the injectable version (that don't cause vaccine derived infections) When your country gets no case for a long enough time and you get a better vaccine coverage, you can "upgrade" the vaccination schedule. (We changed the vaccination schedule a few years ago here in Argentina. Now it is injectable-injectable-oral-oral-oral.)
- kortex 7y ago
  This answers a long-standing question I have had in the back of my mind: Why aren't oral vaccines more common? I imagine it takes a more aggresive formulation to be effective orally, whereas injection is a straight shot into the fray of the immune system's war on pathongens. These more active forms seem to raise the risk of mutation to active virulence.
  - gus_massa 7y ago
    IANAMD. The polio virus usually attack the intestine, moreover it usually attack only the intestine and cause no symptoms. The normal way of transmission is eating something that is contaminated with poop of an infected person. So it is probably easier to create a vaccine that can be "eaten".

by makomk 7y ago

gus_massa 7y ago

Read the recomendad schedule by WHO in https://en.wikipedia.org/wiki/Polio_vaccine#Schedule https://en.wikipedia.org/wiki/Polio_vaccine#Schedule * For countries with endemic: case use a few doses of the oral vaccine (that is more powerful) and at least one dose of the injectable version. * For countries without recent cases an a good vaccination coverage: A few injectable doses and later a few oral doses * For countries with very good coverage and low risk of imported cases: Use only the injectable version (that don't cause vaccine derived infections) When your country gets no case for a long enough time and you get a better vaccine coverage, you can "upgrade" the vaccination schedule. (We changed the vaccination schedule a few years ago here in Argentina. Now it is injectable-injectable-oral-oral-oral.)

kortex 7y ago
This answers a long-standing question I have had in the back of my mind: Why aren't oral vaccines more common? I imagine it takes a more aggresive formulation to be effective orally, whereas injection is a straight shot into the fray of the immune system's war on pathongens. These more active forms seem to raise the risk of mutation to active virulence.
- gus_massa 7y ago
  IANAMD. The polio virus usually attack the intestine, moreover it usually attack only the intestine and cause no symptoms. The normal way of transmission is eating something that is contaminated with poop of an infected person. So it is probably easier to create a vaccine that can be "eaten".