Influenza vaccination US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Influenza vaccination. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Influenza vaccination US Medical PG Question 1: A 24-year-old woman with HIV infection comes to the physician for a follow-up examination. She has been inconsistently taking combined antiretroviral therapy for the past 5 years. She did not receive any childhood vaccinations because her parents were against them. During the consultation, the patient says that she wants to catch up on the missed vaccinations. Laboratory studies show a CD4+ T lymphocyte cell count of 180/mm3. Administration of the vaccine against which of the following agents should be avoided in this patient?
- A. Clostridium tetani
- B. Human papillomavirus
- C. Varicella zoster virus (Correct Answer)
- D. Bordetella pertussis
- E. Haemophilus influenzae
Influenza vaccination Explanation: ***Varicella zoster virus***
- The **varicella zoster vaccine is a live attenuated vaccine**, which is generally contraindicated in individuals with severe **immunodeficiency**, such as HIV patients with a **CD4+ count below 200 cells/mm³**.
- Administering a live vaccine to an immunocompromised patient can lead to **uncontrolled viral replication** and potentially cause the disease it is meant to prevent.
*Clostridium tetani*
- The **tetanus vaccine** is a **toxoid vaccine**, meaning it contains inactivated bacterial toxins, not live organisms.
- It is **safe and recommended** for individuals with HIV, regardless of their CD4+ count, to provide protection against tetanus.
*Human papillomavirus*
- The **HPV vaccine** is a **recombinant vaccine**, consisting of viral-like particles (VLPs) and containing no live virus.
- It is **safe and recommended** for HIV-positive individuals and helps prevent HPV-related cancers.
*Bordetella pertussis*
- The **pertussis vaccine** (part of DTaP or Tdap) is an **acellular vaccine**, containing purified bacterial components, not live bacteria.
- It is **safe and recommended** for HIV patients to protect against whooping cough.
*Haemophilus influenzae*
- The **Haemophilus influenzae type b (Hib) vaccine** is a **conjugate vaccine**, made from bacterial capsular polysaccharide linked to a carrier protein.
- It is **safe and recommended** for HIV-positive individuals, as they are at increased risk for invasive Hib disease.
Influenza vaccination US Medical PG Question 2: An investigator studying influenza virus variability isolates several distinct influenza virus strains from the respiratory secretions of a study subject. Mass spectrometry analysis of one strain shows that it expresses neuraminidase on its surface. Subsequent sequencing of this strain shows that its genome lacks the neuraminidase gene. Which of the following is the most likely explanation for this finding?
- A. Complementation
- B. Recombination
- C. Transduction
- D. Phenotypic mixing (Correct Answer)
- E. Reassortment
Influenza vaccination Explanation: ***Phenotypic mixing***
- **Phenotypic mixing** occurs when a virus genome is packaged into a capsid or envelope proteins derived from a *different* but co-infecting virus. In this case, the influenza strain's genome lacks the **neuraminidase gene**, but it expresses neuraminidase on its surface because it acquired the protein from another co-infecting strain.
- This process is temporary, as the progeny of this mixed virus will replicate normally according to its own **genome**, and thus would not express neuraminidase unless it also inherited the gene.
*Complementation*
- **Complementation** occurs when two viruses infect the same cell, and one virus provides a **gene product** (a protein) that the other virus, which has a defective gene, needs to replicate.
- In complementation, the defective virus *replicates its own genome*, but uses the protein supplied by the other virus; it would not express a protein derived directly from another virus's genome on its surface if its own genome did not encode it.
*Recombination*
- **Recombination** involves the exchange of genetic material between two different but related viruses, resulting in a **hybrid genome** containing genes from both parental viruses.
- If recombination had occurred, the virus's genome *would* contain the neuraminidase gene, which is contradicted by the finding that the genome *lacks* it.
*Transduction*
- **Transduction** is a process where **bacteriophages** (viruses that infect bacteria) transfer bacterial DNA from one bacterium to another. This mechanism is specific to bacteria and their phages, and is not applicable to human influenza viruses.
- This process involves the transfer of genetic material between bacteria via a viral vector, which is unrelated to the expression of a surface protein from a *non-encoded gene* in influenza.
*Reassortment*
- **Reassortment** is a unique characteristic of viruses with **segmented genomes**, such as influenza, where segments can be exchanged between different strains during co-infection.
- If reassortment had occurred, the influenza strain's genome *would have acquired* the neuraminidase gene segment, which contradicts the finding that the genome *lacks* the neuraminidase gene.
Influenza vaccination US Medical PG Question 3: A 4-month-old boy is brought to the physician by his parents for a well-child examination. He has cystic fibrosis diagnosed by newborn screening. His parents report frequent feedings and large-volume and greasy stools. His 4-year-old brother has autism. Current medications include bronchodilators, pancreatic enzyme supplements, and fat-soluble vitamins. He is at the 18th percentile for height and 15th percentile for weight. Scattered wheezes are heard throughout both lung fields. Examination shows a distended and tympanic abdomen with no tenderness or guarding. Which of the following is a contraindication for administering one or more routine vaccinations?
- A. Allergy to egg protein
- B. History of cystic fibrosis
- C. History of febrile seizures
- D. Fever of 38.2°C (100.7°F) following previous vaccinations
- E. History of intussusception (Correct Answer)
Influenza vaccination Explanation: ***History of intussusception***
- A history of **intussusception** is a **contraindication for rotavirus vaccine** administration, as the vaccine itself has a small risk of intussusception, particularly with the first dose.
- The rotavirus vaccine is part of routine childhood immunizations, so this would be a contraindication for one of the routine vaccines.
*Allergy to egg protein*
- Egg allergy is a contraindication primarily for yellow fever vaccine and some influenza vaccines, which are typically not routine vaccinations for a 4-month-old. Many flu vaccines are egg-free or can be safely administered to those with egg allergy under supervision.
- The MMR vaccine is generally safe for those with egg allergy since the amount of egg protein is negligible.
*History of cystic fibrosis*
- **Cystic fibrosis** itself is **not a contraindication** to routine vaccinations; in fact, patients with chronic conditions like CF are often *more* encouraged to receive vaccinations to prevent severe infections.
- The patient's symptoms (poor growth, greasy stools, wheezing) are manifestations of CF, not reasons to defer vaccination.
*History of febrile seizures*
- A history of **febrile seizures** is generally **not a contraindication** to routine vaccinations.
- Parents should be counseled on fever management after vaccination, but the risk of recurrent febrile seizures is not increased by vaccination to a level that warrants deferral.
*Fever of 38.2°C (100.7°F) following previous vaccinations*
- A **low-grade fever** after vaccination is a common and **expected immune response**, not a contraindication for future doses.
- Only a **severe allergic reaction** (e.g., anaphylaxis) to a previous dose of a vaccine or one of its components is a contraindication to subsequent doses of that specific vaccine.
Influenza vaccination US Medical PG Question 4: A young man about to leave for his freshman year of college visits his physician in order to ensure that his immunizations are up-to-date. Because he is living in a college dormitory, his physician gives him a vaccine that prevents meningococcal disease. What type of vaccine did this patient likely receive?
- A. Live, attenuated
- B. Killed, attenuated
- C. Toxoid
- D. Conjugated polysaccharide (Correct Answer)
- E. Killed, inactivated
Influenza vaccination Explanation: ***Conjugated polysaccharide***
- The **meningococcal vaccine** commonly administered to college students is a **polysaccharide vaccine** wherein the polysaccharide antigens are conjugated to a protein carrier.
- This **conjugation** improves the immune response by converting a T-independent antigen into a T-dependent one, inducing better memory responses and allowing for vaccination of infants.
*Live, attenuated*
- Live, attenuated vaccines contain a **weakened form of the pathogen** that can replicate but does not cause disease, such as the MMR or varicella vaccine.
- While they elicit strong, long-lasting immunity, the meningococcal vaccine is not typically of this type due to the risk of opportunistic infection, especially in immunocompromised individuals.
*Killed, attenuated*
- This term is a **contradiction**; vaccines are either **killed (inactivated)** or **live (attenuated)**, but not both.
- Attenuation implies weakening, for which the organism would still be alive.
*Toxoid*
- **Toxoid vaccines** are made from inactivated bacterial toxins, used to protect against diseases where the toxin, not the bacterium itself, causes the disease, such as diphtheria and tetanus.
- Meningococcal disease is primarily caused by **direct bacterial invasion and inflammation**, not solely by a toxin.
*Killed, inactivated*
- **Killed, inactivated vaccines** contain whole pathogens that have been killed and cannot replicate, such as the inactivated poliovirus vaccine.
- While there are inactivated meningococcal vaccines, the most common type for broad use, especially in college settings, is the conjugated polysaccharide vaccine, which elicits a stronger and more long-lasting immune response against multiple serotypes compared to plain inactivated whole-cell vaccines.
Influenza vaccination US Medical PG Question 5: A 3255-g (7-lb) female newborn is delivered at term. Pregnancy and delivery were uncomplicated. On the day of her birth, she is given a routine childhood vaccine that contains a noninfectious glycoprotein. This vaccine will most likely help prevent infection by which of the following pathogens?
- A. Bordetella pertussis
- B. Rotavirus
- C. Poliovirus
- D. Haemophilus influenzae type b
- E. Hepatitis B virus (Correct Answer)
Influenza vaccination Explanation: ***Hepatitis B virus***
- The **Hepatitis B vaccine** is routinely given at birth and contains a **noninfectious glycoprotein** (HBsAg) that elicits an immune response.
- This vaccine is crucial for preventing mother-to-child transmission and provides long-term protection against **Hepatitis B infection**.
*Bordetella pertussis*
- The vaccine for **Bordetella pertussis** (whooping cough) is part of the DTaP vaccine and is typically given at 2 months of age, not at birth.
- The DTaP vaccine usually contains **inactivated toxins** or acellular components, not solely a glycoprotein.
*Rotavirus*
- The **Rotavirus vaccine** is an **oral live-attenuated vaccine** administered in two or three doses, with the first dose typically given at 2 months of age.
- It does not contain a noninfectious glycoprotein.
*Poliovirus*
- The **Poliovirus vaccine** (IPV) is an **inactivated vaccine** given at 2 months of age, and the **oral poliovirus vaccine (OPV)** is a live-attenuated vaccine.
- Neither is routinely given at birth, nor described as a noninfectious glycoprotein.
*Haemophilus influenzae type b*
- The **Haemophilus influenzae type b (Hib) vaccine** is a polysaccharide-protein conjugate vaccine, first administered at 2 months of age.
- While it contains a protein component, it is not typically given at birth.
Influenza vaccination US Medical PG Question 6: A 19-year-old male arrives to student health for an annual check up. He is up to date on his infant and childhood vaccinations up to age 10. At age 12, he received a single dose of the tetanus, diphtheria, and acellular pertussis vaccine, and a quadrivalent meningococcal conjugate vaccine. A month ago, he received the influenza vaccine. The patient has no significant medical history. He takes over the counter ibuprofen for occasional headaches. He has a father with hypertension and hyperlipidemia, and his brother has asthma. He is sexually active with his current girlfriend. He denies tobacco use, illicit drug use, and recent or future travel. The patient’s temperature is 98°F (36.7°C), blood pressure is 118/78 mmHg, pulse is 70/min, and respirations are 14/min with an oxygen saturation of 99% O2 on room air. A physical examination is normal. What of the following is the best recommendation for vaccination?
- A. Human papillomavirus vaccine (Correct Answer)
- B. Hepatitis A vaccine
- C. Herpes zoster vaccine
- D. Pneumococcal vaccine
- E. Tetanus and reduced diphtheria toxoid booster
Influenza vaccination Explanation: ***Human papilloma virus***
- This patient, being 19 years old and **sexually active**, is a prime candidate for the **HPV vaccine** to prevent infections that can lead to various cancers.
- The CDC recommends routine HPV vaccination at age 11-12, but catch-up vaccination is recommended for individuals up to age 26 if not adequately vaccinated previously.
*Hepatitis A vaccine*
- The Hepatitis A vaccine is generally recommended for individuals at **increased risk** of infection, such as travelers to endemic areas, men who have sex with men, or those with chronic liver disease, none of which apply to this patient.
- There is no indication for routine vaccination without specific risk factors in this otherwise healthy young male.
*Herpes zoster vaccine*
- The herpes zoster (shingles) vaccine is recommended for adults **age 50 years and older** to prevent shingles.
- This patient is only 19 years old, making him too young for this vaccine recommendation.
*Pneumococcal vaccine*
- Pneumococcal vaccines (PCV13 and PPSV23) are typically recommended for **young children**, adults **65 years and older**, or individuals with **certain underlying medical conditions** (e.g., chronic heart, lung, or kidney disease, or immunocompromised states).
- This 19-year-old patient has no such risk factors for pneumococcal disease.
*Tetanus and reduced diphtheria toxoid booster*
- The patient received a Tdap vaccine at age 12. A Td booster is recommended **every 10 years** for adults.
- Since it has been only 7 years since his last Tdap vaccine, he is not due for a Td booster at this time.
Influenza vaccination US Medical PG Question 7: A parent presents to her pediatrician requesting information about immunizations for her newborn. The pediatrician explains about basic principles of immunization, types of vaccines, possible adverse effects, and the immunization schedule. Regarding how immunizations work, the pediatrician explains that there are mainly 2 types of vaccines. The first type of vaccine provides stronger and more lasting immunity as it induces both cellular and humoral immune responses. The second type of vaccine produces mainly a humoral response only, and its overall efficacy is less as compared to the first type. Which of the following vaccines belongs to the first type of vaccine that the pediatrician is talking about?
- A. Hepatitis A vaccine
- B. Polio vaccine (Salk)
- C. Yellow fever vaccine (Correct Answer)
- D. Rabies vaccine
- E. Hepatitis B vaccine
Influenza vaccination Explanation: ***Yellow fever vaccine***
- The Yellow fever vaccine is a **live-attenuated vaccine**, which mimics natural infection and effectively stimulates both **cellular and humoral immune responses**, leading to strong and long-lasting immunity.
- Live-attenuated vaccines contain a weakened form of the pathogen, allowing for replication within the host and robust immune system activation.
*Hepatitis A vaccine*
- The Hepatitis A vaccine is an **inactivated vaccine**, which primarily induces a **humoral (antibody-mediated) immune response**.
- Inactivated vaccines generally do not stimulate a strong cellular immune response and often require booster doses to maintain protective immunity.
*Polio vaccine (Salk)*
- The Salk polio vaccine is an **inactivated polio vaccine (IPV)**, meaning it contains killed viral particles.
- As an inactivated vaccine, it mainly elicits a **humoral immune response** producing circulating antibodies but less mucosal or cellular immunity.
*Rabies vaccine*
- The Rabies vaccine is an **inactivated vaccine** given after exposure or for pre-exposure prophylaxis.
- It primarily induces a **humoral antibody response** rather than a strong cellular immune response.
*Hepatitis B vaccine*
- The Hepatitis B vaccine is a **recombinant vaccine**, containing only a portion of the viral antigen (HBsAg).
- This type of vaccine primarily stimulates a **humoral immune response** leading to antibody production, which is effective but does not typically induce a strong cellular response like live vaccines.
Influenza vaccination US Medical PG Question 8: A 24-year-old newly immigrated mother arrives to the clinic to discuss breastfeeding options for her newborn child. Her medical history is unclear as she has recently arrived from Sub-Saharan Africa. You tell her that unfortunately she will not be able to breastfeed until further testing is performed. Which of the following infections is an absolute contraindication to breastfeeding?
- A. Human Immunodeficiency Virus (HIV) (Correct Answer)
- B. Latent tuberculosis
- C. Hepatitis B
- D. Hepatitis C
- E. All of the options
Influenza vaccination Explanation: ***Human Immunodeficiency Virus (HIV)***
- In developed countries where safe alternatives are available, **HIV-positive mothers** are advised against breastfeeding due to the risk of **vertical transmission** through breast milk.
- This is considered an **absolute contraindication** in settings where formula feeding is accessible and safe.
*Latent tuberculosis*
- **Latent tuberculosis** is not a contraindication to breastfeeding; mothers can breastfeed while receiving treatment.
- Active, untreated tuberculosis, however, generally requires temporary separation of mother and child until the mother is no longer infectious, but pumping and feeding expressed milk is often still an option.
*Hepatitis B*
- **Hepatitis B** infection in the mother is not a contraindication to breastfeeding, especially if the infant receives **hepatitis B vaccine** and **Hepatitis B Immune Globulin (HBIG)** at birth.
- Breastfeeding is considered safe and does not increase the risk of transmission to the infant.
*Hepatitis C*
- **Hepatitis C** is generally **not a contraindication** to breastfeeding, as studies have shown a very low risk of transmission through breast milk.
- Breastfeeding is supported unless the mother has **cracked or bleeding nipples**, which could potentially allow viral transmission.
*All of the options*
- This option is incorrect because **only HIV** is considered an absolute contraindication to breastfeeding in settings where safe alternatives are available.
- Latent TB, Hepatitis B, and Hepatitis C alone do not preclude breastfeeding.
Influenza vaccination US Medical PG Question 9: A 2-year-old boy presents to the pediatrician for evaluation of an elevated temperature, sore throat, runny nose, and lacrimation for the past week, and a rash which he developed yesterday. The rash began on the patient’s face and spread down to the trunk, hands, and feet. The patient’s mother gave him ibuprofen to control the fever. The child has not received mumps, measles, and rubella vaccinations because he was ill when the vaccine was scheduled and was later lost to follow-up. The vital signs include blood pressure 90/50 mm Hg, heart rate 110/min, respiratory rate 22/min, and temperature 37.8°C (100.0℉). On physical examination, the child was drowsy. His face, trunk, and extremities were covered with a maculopapular erythematous rash. Two irregularly-shaped red dots were also noted on the mucosa of the lower lip. The remainder of the physical examination was within normal limits. What is the probable causative agent for this child’s condition?
- A. Group A Streptococcus
- B. Rubulavirus
- C. Influenzavirus
- D. Morbillivirus (Correct Answer)
- E. Herpesvirus
Influenza vaccination Explanation: ***Morbillivirus***
- The constellation of symptoms—**elevated temperature**, **sore throat**, **runny nose**, **lacrimation**, a **maculopapular erythematous rash** that began on the face and spread downward, and especially the **irregularly-shaped red dots on the mucosa of the lower lip** (likely **Koplik spots**)—are classic for **measles**, caused by Morbillivirus.
- The patient's **unvaccinated status** against MMR further supports measles as the most probable diagnosis, as it is a highly contagious disease prevented by vaccination.
*Group A Streptococcus*
- This bacterium causes **scarlet fever**, characterized by a **sandpaper-like rash** and **strawberry tongue**, not a maculopapular rash spreading from face to extremities with Koplik spots.
- While it can cause pharyngitis and fever, the specific rash progression and oral lesions rule out Group A Streptococcus.
*Rubulavirus*
- Rubulavirus causes **mumps**, which primarily presents with **parotitis** (swelling of parotid glands), fever, and headache.
- It does not typically cause a generalized maculopapular rash or Koplik spots, making it an unlikely cause for the described symptoms.
*Influenzavirus*
- Influenzavirus causes **influenza**, characterized by sudden onset of high fever, cough, myalgia, and headache.
- While it can cause fever and respiratory symptoms, it does not typically present with a widespread maculopapular rash or Koplik spots.
*Herpesvirus*
- Herpesviruses cause a variety of conditions, including **chickenpox** (Varicella-zoster virus), which presents with **vesicular lesions** that crust over, and **roseola infantum** (HHV-6/7), which primarily causes a high fever followed by a non-pruritic rash appearing *after* the fever subsides.
- Neither of these typically presents with Koplik spots or the specific maculopapular rash progression described.
Influenza vaccination US Medical PG Question 10: An investigator is studying the mechanism of HIV infection in cells obtained from a human donor. The effect of a drug that impairs viral fusion and entry is being evaluated. This drug acts on a protein that is cleaved off of a larger glycosylated protein in the endoplasmic reticulum of the host cell. The protein that is affected by the drug is most likely encoded by which of the following genes?
- A. gag
- B. env (Correct Answer)
- C. tat
- D. pol
- E. rev
Influenza vaccination Explanation: ***env***
- The **env (envelope) gene** of HIV encodes for the precursor protein **gp160**, which is then cleaved by host cellular proteases into **gp120** and **gp41** within the endoplasmic reticulum.
- **gp120** and **gp41** together form the viral envelope glycoproteins responsible for viral binding to host cells and **fusion/entry**, making them the target of drugs that impair these processes.
*gag*
- The **gag (group-specific antigen) gene** encodes for structural proteins of the viral core, such as **p24 (capsid protein)**, p17 (matrix protein), and p7 (nucleocapsid protein).
- These proteins are primarily involved in the assembly of new virions and do not directly mediate viral fusion and entry.
*tat*
- The **tat (trans-activator of transcription) gene** encodes a regulatory protein that significantly enhances the transcription of viral genes.
- It plays a crucial role in the viral life cycle by increasing the efficiency of HIV gene expression, but it is not directly involved in viral fusion or entry.
*pol*
- The **pol (polymerase) gene** encodes for essential viral enzymes, including **reverse transcriptase**, integrase, and protease.
- These enzymes are critical for converting viral RNA into DNA, integrating viral DNA into the host genome, and cleaving viral polyproteins, respectively, but they are not involved in mediating viral entry.
*rev*
- The **rev (regulator of virion expression) gene** encodes a regulatory protein that facilitates the transport of unspliced and partially spliced viral RNAs from the nucleus to the cytoplasm.
- This transport is crucial for the synthesis of structural and enzymatic proteins and for packaging viral RNA into new virions, but it does not directly participate in viral fusion and entry.
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