Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
The centre of the nucleus is an atom
Answer:
the balance is everything must have a process of living and dying in an ecosystem. such as, an animal killing another animal for prey to eat it, that is a process. in a water ecosystem, fish lay eggs and come out and usually get eaten by a bigger animal, as they grow up, usually by bigger fish itself such as the Grayling.
Explanation:
Neutron stars are created when
giant stars die in supernovas and
their cores collapse, with the
protons and electrons essentially
melting into each other to form
neutrons. Credit: NASA/Dana
Berry
The answers are following
1)a
2)a
3)d
