True or false a. The immune system normally produces "self-antibodies" to recognize self cells b. Vaccines work by showing the immune system a "preview" of a virus or other pathogen. c. Viruses cannot evolve because they are not alive. d. We can stop vaccinating for a disease once no more cases are being reported. Choose one of the FALSE statements from the previous question and explain why it is false.

All of the following statements about polioviruses are correct except _____. a. Poliovirus vaccines are produced in both inactivated and live-attenuated forms. b. The oral poliovirus vaccine is composed of three liveattenuated viral strains. c. Poliovirus infects both humans and cattle. d. If genetic reversion of strain 3 occurs when the virus is replicating in vaccinated people, pathogenesis may occur. e. In the United States, the recommended vaccine for poliovirus is the inactivated poliovirus vaccine (IPV).

Using two antibiotics together has a high probability of producing multi-drug resistant strains. a. True b. False

From: "Why our flu vaccines can't keep up" In a population with herd immunity... O The virus spreads, but the symptoms it produces are mild. O The virus spreads, but the symptoms it produces are short-lived. O The virus does not spread because there are too few hosts to maintain the virus population. O The virus does not spread because the hosts move, or migrate, too quickly from one area to another.

One of the leading causes of morbidity and mortality after a person gives birth is sepsis. Some cases are caused by invasive Group A streptococcus. What is a potential reservoir for this pathogen?   A. There are so many species of Group A streptococcus that it is impossible to identify a reservoir.   B. It can be normal flora in the person's throat, and respiratory secretions can be transmitted by direct contact.   C. It is normal flora in the blood, and therefore colonizes the surface of the baby's skin as the baby is being born.

Please help with the following: The frequency of the CCR5Δ32 allele varies between populations. Research has shown that individuals with this allele are resistant to HIV with an increased frequency in European populations. This conferred resistance is a direct result of: A. An adaptation to smallpox. B. An adaptation of domesticated animals. C. An adaptation to malaria. D. None of the above. E. An adaptation to thousands of years of exposure to infectious diseases.

There are two tests for a disease, one is rapid and the other is slow. Given that an individual is infected, the rapid test will register positive 40% of the time, while the slow test will register positive 80% of the time; additionally, both tests will be positive 35% of the time. Suppose in the above example that people not infected always test negative for both tests.   Suppose in the above example that people not infected always test negative for both tests.   5. Of the people in the population who are tested, 75% of their results from the slow test are positive. What is the chance that a persons has the virus conditioned on getting negative result on the slow test?

The whooping cough vaaccine and the MMR vaccine are what type of vaccines? a. conjugated b. natural c. globulin d. gamma e. whole cell / virus

Answer question 33

Use this for the next three questions: In two communities of similar size and age structure (A and B), there were outbreaks of viral illnesses (Virus A in community A, and Virus B in community B), both of which were traced back to a single source. Exposure to these viruses in each community confers permanent immunity. In community A, 200 susceptible people were exposed to an index case, 150 people were infected (not including the index case), 75 people became ill, and 40 people died. In community B, pathogenicity was 40%, infectivity was 90%, and virulence was 60%. Choose the best response:Which virus had the greatest infectivity?