M2 Infection Prevention - Modules 2

Infection Prevention Exam 1

Vaccine Characterization (3)

Vaccines may be categorized as whole-pathogen vaccines, subunit vaccines, or nucleic acid vaccines.

Whole-pathogen vaccines

Consist of either live attenuated or inactivated microorganisms

Live attenuated vaccines

Use a weakened form of the pathogen, which after administration replicates and induces an immune response.NO

Subunit vaccines

Are prepared from fractional antigenic components of an organism and may be protein-based, pure polysaccharide-based, conjugate polysaccharide-based, or recombinant protein-based.

Nucleic acid vaccines

• Introduce the specific genetic material encoding the target antigen or antigens against which an immune response is sought.

• Once introduced, the body’s own cells then use the genetic material to produce the antigens.

• Potential advantages of this approach include no risk of infection; improved vaccine stability; stimulation of broad long-term immunity; and rapid, inexpensive, and scalable vaccine manufacturing.

What do antitoxins do?

Antitoxins inactivate toxic microbial protein products (toxins).

What do opsonins do?

Opsonins facilitate phagocytosis of microorganisms, making them easier for immune cells to engulf and destroy.

What do lysins do?

Lysins damage the microbial cell membrane, leading to destruction of the microorganism.

What do antiadhesins do?

Antiadhesins prevent microorganisms from adhering to host cell components, helping block infection.

What do neutralizing antibodies do?

Neutralizing antibodies prevent the proliferation of microorganisms by blocking their ability to infect or spread.

What are immunoglobulins (IGs)?

Immunoglobulins (IGs) are predominantly IgG antibodies obtained from human or animal donors who have recovered from an infectious disease or have been previously immunized.

What type of immunity do immunoglobulins (IGs) provide?

IGs provide immediate, short-term protection, known as passive immunity.

Why are immunoglobulins (IGs) used?

IGs are used to provide protection before a vaccine can induce active immunity.

When is passive immunity with immunoglobulins (IGs) especially useful?

Passive immunity is useful when:

• A vaccine is unavailable

• A vaccine is contraindicated

• An individual cannot produce antibodies

Are Vaccines Safe

Yes

What is a live attenuated vaccine?

A vaccine containing a weakened (attenuated) live pathogen that stimulates an immune response. Compared with inactivated vaccines, it:

• Has higher rates of adverse effects (especially fever).

• May infect the fetus, so it is generally avoided during pregnancy unless the immediate risk of infection is high.

• Should be used with caution in immunocompromised individuals.

What is an inactivated vaccine?

A vaccine containing a killed or inactivated pathogen that cannot replicate or cause infection. Compared with live attenuated vaccines, it:

• Has lower rates of adverse effects.

• Cannot infect the fetus.

• Is generally safer for pregnant and immunocompromised individuals.

Most common allergic reaction from vaccines

• Egg allergy

Best ways to give vaccines?

Most vaccines for adults are given by subcutaneous (SC) or intramuscular (IM) injection. When administering vaccines, it is imperative to aspirate before depressing the plunger to make certain that the product is not injected intravenously.

Hepatitis B (HBV) Vaccine

Hepatitis B (HBV) – Mandated Vaccine for Occupational Healthcare Personnel (OHCP)

• HBV vaccination is mandated for all OHCP due to the risk of occupational exposure to blood and other potentially infectious materials (OPIM).

• Vaccination should be completed during professional training, when the risk of exposure is highest.

• Hepatitis B vaccines provide active immunity and are administered as 2- or 3-dose IM series (deltoid muscle preferred).

• Post-vaccination antibody testing (anti-HBs) is recommended 1–2 months after the final dose to confirm immunity (≥10 mIU/mL).

• If an exposed worker is unvaccinated or fails to develop immunity, Hepatitis B Immune Globulin (HBIG) provides passive immunity and should be administered within 24 hours (up to 1 week) after exposure, along with initiation of the hepatitis B vaccine series when appropriate.

Influenza – Strongly Recommended Vaccine for Occupational Healthcare Personnel (OHCP)

• Annual influenza vaccination is strongly recommended for all OHCP, including students, to protect both healthcare workers and patients from healthcare-associated transmission.

• Influenza is caused by types A and B viruses and spreads through respiratory droplets, direct contact with respiratory secretions, and contaminated surfaces.

• Three vaccine types are available:

  • Inactivated Influenza Vaccine (IIV) – IM injection (most commonly used)

  • Recombinant Influenza Vaccine (RIV) – IM injection (egg-free option)

  • Live Attenuated Influenza Vaccine (LAIV/FluMist) – intranasal; for healthy adults only and should be avoided around immunosuppressed patients for 7 days.

• Vaccination is required every year because circulating influenza strains change annually.

• Antiviral medications (e.g., oseltamivir, zanamivir, peramivir, baloxavir) can reduce illness severity when started within 48 hours of symptom onset but are not substitutes for annual vaccination.

Measles, Mumps, & Rubella (MMR) – Strongly Recommended Vaccine for Occupational Healthcare Personnel (OHCP)

• OHCP should have documented immunity to measles, mumps, and rubella through:

  • Previous physician-diagnosed infection,

  • Laboratory evidence of immunity, or

  • Appropriate MMR vaccination.

• MMR is the preferred vaccine and contains live attenuated measles, mumps, and rubella viruses.

• Routine adult schedule: 2 subcutaneous (SC) doses (timing depends on vaccine/product and immunization status).

• Measles, mumps, and rubella are highly contagious respiratory infections spread through airborne droplets and respiratory secretions.

• Key point: There is no evidence supporting a causal link between the MMR vaccine and autism.

Varicella (Chickenpox) & Herpes Zoster (Shingles) – Strongly Recommended Vaccine for Occupational Healthcare Personnel (OHCP)

• OHCP should have documented immunity to VZV through:

  • Physician-diagnosed varicella (chickenpox) or herpes zoster (shingles),

  • Laboratory evidence of immunity, or

  • Age-appropriate vaccination.

• Varicella-zoster virus (VZV) causes both chickenpox (primary infection) and shingles (reactivation) and spreads through airborne droplets and direct contact with lesions.

• Vaccines:

  • Varivax®: Live attenuated vaccine; 2 SC doses for varicella immunity.

  • Shingrix®: Recombinant vaccine; 2 IM doses for shingles prevention in adults ≥50 years and immunocompromised adults ≥19 years.

• Post-exposure prophylaxis: VariZIG (VZIG) provides passive immunity and should be given within 96 hours of exposure to high-risk susceptible individuals, including pregnant women.

Tetanus, Diphtheria, & Pertussis (Tdap/Td) – Recommended Vaccine for Occupational Healthcare Personnel (OHCP)

• Tetanus, diphtheria, and pertussis (Tdap/Td) vaccination is recommended for all OHCP to prevent occupational and community transmission.

• Tetanus: Caused by Clostridium tetani toxin from contaminated wounds; symptoms include muscle stiffness, spasms, and difficulty swallowing.

• Diphtheria: Caused by Corynebacterium diphtheriae spread through respiratory droplets; hallmark sign is a thick gray membrane in the throat.

• Pertussis (whooping cough): Caused by Bordetella pertussis; characterized by severe coughing fits, inspiratory “whoop,” and vomiting.

• Vaccines:

  • Tdap: Recommended for OHCP with uncertain vaccination history and provides protection against tetanus, diphtheria, and pertussis.

  • Td/Tdap booster: Recommended every 10 years.

  • Tdap may also be used for wound management when indicated.

Human Papillomavirus (HPV) – Recommended Vaccine for Prevention of HPV-Related Disease

• HPV is the most common sexually transmitted infection and spreads through contact with infected skin or genital/oral mucous membranes.

• High-risk HPV types (especially 16 and 18) are associated with:

  • Cervical cancer

  • Oral and upper respiratory tract cancers

  • Other HPV-related cancers

• HPV vaccine (Gardasil 9®):

  • Recombinant 9-valent vaccine protecting against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58.

  • Prevents genital warts and HPV-related precancerous lesions and cancers.

  • Approved for males and females ages 9–45 years.

• Vaccination schedule: 3 IM doses at 0, 1–2, and 6 months for individuals starting the series at older ages or with certain risk factors.

• Common adverse effects: Injection-site pain, swelling, redness, possible yeast-related allergic reactions, and fainting (especially in adolescents/young adults).

SARS-CoV-2 (COVID-19) – Occupational Risk & Prevention

• SARS-CoV-2 is the virus that causes COVID-19 and spreads primarily through respiratory droplets from coughing, sneezing, or talking.

• Symptoms can range from mild to severe and may include:

  • Fever, chills, cough

  • Sore throat

  • Muscle/body aches

  • Loss of taste or smell

  • Nausea, vomiting, or breathing difficulties

• Symptoms typically appear 2–14 days after exposure, but asymptomatic transmission can occur.

• Risk of severe disease is higher in:

  • Adults ≥65 years old

  • Individuals with underlying conditions such as cancer, chronic lung or kidney disease, diabetes, obesity, heart disease, pregnancy, HIV, and immunocompromising conditions.

• Prevention strategies include recommended COVID-19 vaccination, infection-control practices, and reducing exposure to respiratory secretions.

Meningococcal Disease – High-Risk Vaccine Recommendation

• Neisseria meningitidis causes bacterial meningitis and spreads through respiratory droplets and secretions.

• Symptoms: Fever, headache, and stiff neck.

• Vaccination is not routinely required for OHCP unless high-risk factors exist:

  • Asplenia or complement deficiencies

  • Travel to outbreak/high-risk areas

  • Laboratory exposure to N. meningitidis

• Vaccines available:

  • MenACWY (serogroups A, C, Y, W-135)

  • MenB (serogroup B)

  • MenABCWY (combination vaccine)

• Boosters may be needed if risk continues.

Pneumococcal Disease – Recommended Vaccine for High-Risk Adults

• Streptococcus pneumoniae causes serious infections such as pneumonia, meningitis, sinusitis, and bloodstream infections.

• Spread occurs through airborne respiratory droplets.

• Highest risk groups:

  • Adults ≥65 years

  • Individuals with compromised immune systems or medical risk factors

• Vaccines available:

  • PCV20 (Prevnar 20) – single IM dose option

  • PCV15 (Prevnar 15) – may be followed by PPSV23

  • PPSV23 (Pneumovax 23) – protects against 23 serotypes

• Common adverse effects: Injection-site pain, redness, swelling, fatigue, headache, or muscle/joint pain.

Hepatitis A – Recommended Vaccine for High-Risk Individuals

Hepatitis A – Recommended Vaccine for High-Risk Individuals

• Hepatitis A virus (HAV) spreads through the fecal-oral route via contaminated food, water, or person-to-person contact.

• Symptoms in adults may include fever, fatigue, nausea, abdominal pain, dark urine, and jaundice.

• HAV infection is self-limiting and does not cause chronic liver disease.

Hepatitis A Vaccination

• Recommended for individuals at increased risk, including:

  • Chronic liver disease or HIV

  • International travelers

  • Men who have sex with men

  • People who use illicit drugs

  • Those experiencing homelessness

  • Individuals with potential healthcare exposure

• Vaccines:

  • Vaqta® / Havrix®: 2 IM doses

  • Twinrix® (Hep A + Hep B): 3 IM doses

• Passive protection: Immune globulin provides short-term protection and should be given within 2 weeks after exposure for best effectiveness.

Documenting Immunization Compliance for OHCP (3)

Documenting Immunization Compliance for OHCP

• An immunization record should be established at initial employment for all Occupational Healthcare Personnel (OHCP).

• Immunity should be verified through documentation of:

  • 1. -diagnosed infection

  • 2. Laboratory evidence of immunity

  • 3. Age-appropriate vaccination