The term used for a group of words that does not contain a verb or a subject and that acts as a single part of speech is D. a phrase.
A species that is not native to an ecosystem but is introduced artificially. Usually cause harm to the native species in the area.
<span>James Hutton developed the concept of erosion and deposition.</span>
The post-eradication era is a period of history for which there has been no precedent whatsoever in terms of a zero base of immunity. Cessation of immunization will eventually create a population susceptible to widespread infection in the event of accidental or intentional reintroduction or re-emergence of the eradicated virus. Thus, even after immunization ceases, vaccine production must continue.
However, many currently available vaccines may not be appropriate for continued post-eradication vaccine production or reinstatement. Vaccines must be continually improved and ongoing vaccination research maintained. Other potentially useful antiviral strategies—antivirals, prophylaxis, and probiotics—must also be considered as means to strengthen the immune system and serve as adjuvant or prophylactic therapies.
In the case of polio, for example, it remains to be determined which vaccine (oral polio vaccine [OPV] or inactivated polio vaccine [IPV]), or variant thereof, should be produced in the post-eradication, post-vaccination era. A detailed plan for vaccine production will require more information on OPV-derived viral persistence and transmission, as well as continuing dialogue between public health and research communities in order to ensure that appropriate vaccination research continues.
