Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered...

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 22 to 26.

        Vaccines train the immune system to recognize and fight harmful pathogens. Most vaccines introduce a harmless version of the virus or bacteria, prompting the body to produce antibodies. (22) _______. These antibodies stay in the system, ready to respond quickly if the real threat appears. Scientists often use weakened or inactive forms of the virus to trigger this response. (23) _______. Some newer vaccines use genetic instructions to help cells build a harmless protein found on the virus. This method has proven effective in recent outbreaks. (24) _______. For example, mRNA vaccines became widely known during the COVID-19 pandemic. Developing a vaccine involves multiple stages: lab research, animal testing, and human trials. (25) _______. Each phase must follow strict safety protocols and be approved by health authorities. Once approved, vaccines are distributed through public health systems. (26) _______.

(Adapted from National Geographic, “Searching for a Coronavirus Vaccine: How Would It Work?”)

Question 22. A. This immunological response prepares the body to defend against future encounters with actual pathogens

B. These antibody-producing mechanisms enable the immune system to respond more rapidly to subsequent exposures

C. This defensive preparation allows the body to recognize and neutralize genuine threats when they appear

D. These protective protocols help the immune system mount effective responses against real infections

Question 23. A. However, this approach occasionally produces mild adverse reactions in certain individuals

B. Consequently, the pathogen becomes significantly more dangerous when introduced to the immune system

C. Therefore, the immune response typically fails to recognize these weakened viral components

D. Meanwhile, bacterial multiplication accelerates dramatically following the initial vaccine administration

Question 24. A. This innovative methodology has fundamentally transformed contemporary vaccine development and production processes

B. Such technological breakthroughs have revolutionized how researchers approach immunization strategies

C. These advances have substantially altered the landscape of modern preventive medicine

D. This approach has significantly influenced the trajectory of recent pharmaceutical research

Question 25. A. Each developmental phase requires meticulous planning and comprehensive expert oversight

B. Every testing stage demands rigorous protocols and thorough scientific evaluation

C. All trial phases necessitate careful coordination and extensive regulatory review

D. Each research stage involves detailed procedures and systematic safety assessment

Question 26. A. This systematic distribution ensures communities receive protection and minimizes outbreak frequency

B. Such coordinated delivery programs help populations achieve immunity and reduce disease transmission

C. These organized immunization campaigns enable societies to control epidemics and prevent widespread illness

D. This structured approach allows healthcare systems to provide coverage and limit infection rates