Active immunity — a vaccine presents an antigen so the body makes its own antibodies and memory B and T cells. Protection takes 1–2 weeks or more to develop, may need several doses, and lasts months to a lifetime.
Passive immunity — ready-made antibodies are given. Protection is immediate but temporary (weeks to months) and creates no memory. Used after exposure, when there is no time to respond to a vaccine, or when the client cannot respond.
| Product type | How it works | Examples |
|---|
| Live attenuated vaccine | Weakened organism replicates briefly → strong, long-lasting immunity | MMR, varicella, live zoster (no longer in the US), rotavirus, BCG, oral polio, yellow fever, intranasal influenza |
| Inactivated (killed) vaccine | Whole killed organism | Inactivated polio (IPV), hepatitis A, rabies, inactivated influenza |
| Subunit / recombinant | Purified protein antigen | Hepatitis B, recombinant zoster, HPV, RSV (older adult and maternal) |
| Toxoid | Inactivated toxin → antibodies neutralize the toxin | Tetanus and diphtheria (Td, Tdap, DTaP) |
| Conjugate | Polysaccharide linked to a protein → effective in infants under 2 years | Hib, pneumococcal conjugate (PCV), meningococcal conjugate |
| mRNA | Lipid-coated mRNA instructs cells to make the antigen | COVID-19 vaccines |
| Immune globulin (IG), pooled | Antibodies from many donors | IM immune globulin, IVIG, subcutaneous IG |
| Hyperimmune globulin | High antibody level against one agent | HBIG, rabies IG (RIG), tetanus IG (TIG), varicella-zoster IG (VariZIG), Rh(D) IG (RhIG) |
| Monoclonal antibody | Single laboratory-made antibody | Nirsevimab, clesrovimab (RSV in infants) |
| Antitoxin / antivenom | Often animal-derived (equine) antibodies | Botulism antitoxin, snake antivenom |
Selected adult and pregnancy vaccines (always confirm the current national schedule)
| Vaccine | Key use (US pattern) | Key point |
|---|
| Influenza (inactivated or recombinant) | Every year for everyone 6 months and older | Egg allergy is not a contraindication |
| Tdap / Td | Tdap once as an adult, then Td or Tdap every 10 years; Tdap in every pregnancy at 27–36 weeks | Maternal antibodies protect the newborn from pertussis |
| Hepatitis B | Universal for infants (birth dose) and adults 19–59; 60 and older with risk factors or on request | Healthcare workers: check anti-HBs after the series |
| Recombinant zoster | 2 doses for adults 50 and older, and 19 and older who are immunocompromised | Non-live — usable in immunosuppression |
| Pneumococcal conjugate (PCV20 or PCV21) | Adults 50 and older, and younger adults with risk conditions | One dose completes most adult series |
| RSV (older adults) | Single dose for older adults per age and risk thresholds in the current schedule | Rare Guillain–Barré syndrome signal |
| RSV (maternal) | One dose at 32–36 weeks in RSV season | Alternative to infant monoclonal antibody |
| HPV | Routine at 11–12 years (can start at 9); catch-up through 26 | 2 doses if started at 9–14 years; 3 doses if started at 15 or older or immunocompromised |
| MMR, varicella | Nonimmune adults, postpartum clients | Live — not in pregnancy |
Immune globulins for postexposure prophylaxis
| Product | Situation | Key point |
|---|
| HBIG + hepatitis B vaccine | Infant of an HBsAg-positive mother (within 12 hours of birth); needle-stick from a positive source in a nonimmune person | Separate injection sites |
| Rabies IG + rabies vaccine | Category III exposure in an unvaccinated person (see below) | US: HRIG 20 IU/kg infiltrated into and around the wound, any remainder IM away from the vaccine site. WHO: infiltrate the wound only; equine RIG 40 IU/kg. Vaccine IM in the deltoid (never gluteal) |
| TIG + tetanus toxoid | Dirty or major wound with fewer than 3 or unknown prior tetanus doses | TIG 250 units IM. With 3 or more prior doses: toxoid only if the last dose was 10 or more years ago (clean minor wound) or 5 or more years ago (dirty or major wound) |
| VariZIG | Exposed pregnant nonimmune client, immunocompromised person, certain newborns | Give as soon as possible, up to 10 days after exposure |
| RhIG | Rh-negative, unsensitized pregnant client | 300 mcg IM at about 28 weeks, and within 72 hours after birth of an Rh-positive infant |
| IVIG | Primary immunodeficiency, immune thrombocytopenia, Kawasaki disease, Guillain–Barré syndrome, myasthenic crisis | Blood product — consent |
| Nirsevimab | Infants under 8 months in their first RSV season if the mother did not receive the RSV vaccine at least 14 days before birth; high-risk infants in the second season | Single IM dose |
Rabies postexposure prophylaxis (PEP) — wash the wound with soap and water for 15 minutes first.
| WHO category | Exposure | Action |
|---|
| I | Touching or feeding animals, licks on intact skin | No PEP |
| II | Nibbling of uncovered skin, minor scratches or abrasions without bleeding | Vaccine only |
| III | Bites or scratches through the skin, licks on broken skin or mucosa, any bat contact | Vaccine + RIG |
- US, unvaccinated: HRIG on day 0 + vaccine IM on days 0, 3, 7, 14 (add day 28 if immunocompromised)
- Previously vaccinated: vaccine on days 0 and 3 only, no RIG
- WHO 2018 / Philippines: intradermal, 2 sites on days 0, 3, 7 (1-week regimen), or IM on days 0, 3, 7, and 14–28; RIG for category III (in the Philippines, category II exposures on the head and neck are managed as category III)
| Product | Key adverse effects |
|---|
| All vaccines | Local pain, redness, swelling; low-grade fever, fatigue, headache; syncope (especially adolescents); anaphylaxis (rare, within minutes) |
| Live vaccines | Mild version of the disease (MMR rash and fever at 7–12 days; varicella vaccine rash); disseminated infection in severe immunodeficiency |
| Rotavirus | Intussusception (small risk, mainly the week after dose 1) |
| MMRV (first dose, 12–47 months) | Higher febrile seizure risk than separate MMR and varicella |
| Influenza, RSV (older adult) | Rare Guillain–Barré syndrome |
| mRNA COVID-19 | Myocarditis/pericarditis, mainly in young males within a week |
| Recombinant zoster | Strong local and systemic reactions for 2–3 days |
| BCG | Local ulcer and scar (expected); abscess, lymphadenitis; disseminated BCG in immunodeficiency |
| IVIG | Headache, flushing, chills, aseptic meningitis; boxed warnings: thrombosis and kidney dysfunction / acute renal failure; hemolysis; volume overload; anaphylaxis in IgA-deficient clients with anti-IgA antibodies |
| Animal-derived antitoxins | Anaphylaxis, serum sickness (fever, rash, joint pain 7–14 days later) |
Contraindications
- Anaphylaxis to a previous dose or a vaccine component — the only contraindication common to all vaccines
- Live vaccines: pregnancy and severe immunodeficiency (chemotherapy, high-dose corticosteroids, transplant drugs, biologics, advanced HIV with low CD4, SCID)
- Rotavirus: SCID or prior intussusception
- DTaP/Tdap: encephalopathy within 7 days of a previous pertussis-containing dose
Precautions (not contraindications)
- Moderate or severe acute illness — delay; mild illness with low fever is not a reason to delay
- History of Guillain–Barré syndrome within 6 weeks of a previous influenza or tetanus-containing dose
- Recent antibody-containing blood product or IG: delays MMR and varicella vaccines (interval of 3–11 months depending on product and dose)
Pregnancy and breastfeeding
- Recommended in pregnancy: inactivated influenza, Tdap each pregnancy, RSV vaccine (32–36 weeks, seasonal), COVID-19 as per the current schedule
- Avoid live vaccines; after MMR or varicella, avoid pregnancy for 4 weeks. Inadvertent vaccination is not a reason to terminate pregnancy
- Breastfeeding is not a contraindication to any vaccine except yellow fever in some situations
Interactions and timing
- Live injectable vaccines: same day or at least 28 days apart
- Give MMR or varicella at least 2 weeks before an IG product when possible
- TST and MMR: same day or wait 4 weeks after MMR (measles vaccine can cause a false-negative TST)
- Antivirals (acyclovir, valacyclovir) taken around varicella or zoster live vaccine reduce its effect; influenza antivirals inactivate intranasal live influenza vaccine
- Immunosuppressive drugs blunt vaccine response — vaccinate before therapy when possible
- RhIG and MMR postpartum: give both; check rubella immunity about 3 months later
- HBIG, RIG, TIG with their vaccines: different syringes and different sites — never mix
- Be ready for anaphylaxis before giving any vaccine or IG — epinephrine 1 mg/mL, airway equipment, and a protocol in the room
- Screen before every dose: current illness, allergies and previous reactions, immune status and medications, pregnancy, recent blood products or IG, and the vaccination record
- Informed consent; give the required information (in the US, the current Vaccine Information Statement before each dose)
- Cold chain: refrigerate most vaccines at 2–8 °C (36–46 °F); never freeze liquid inactivated vaccines; varicella and MMRV are kept frozen; check expiry and use the correct diluent; follow manufacturer handling for mRNA vaccines
- Correct route and site: most inactivated vaccines IM (deltoid in adults, 90°, no aspiration); MMR SC or IM; varicella SC; BCG intradermal; rotavirus oral
- Observe for 15 minutes after vaccination, seated or lying down (syncope and anaphylaxis); 30 minutes for clients with a history of anaphylaxis per policy
- IVIG infusion: hydrate first; premedicate as ordered; start slowly and increase the rate in steps; vital signs with each rate change; watch for headache, dyspnea, hypotension; creatinine and urine output in at-risk clients; assess for thrombosis
- RhIG: confirm the Rh-negative, antibody-negative status and give IM; it is a blood product
- Document: product, manufacturer, lot number, expiry, dose, route, site, date, information given, and administrator; update the registry; report adverse events (in the US, to VAERS)
- Expect soreness and mild fever for 1–2 days; use a cool compress; take acetaminophen or ibuprofen for discomfort afterward if needed
- Report hives, facial swelling, difficulty breathing, dizziness immediately (anaphylaxis)
- After MMR or varicella vaccine, avoid pregnancy for 4 weeks
- Tdap in every pregnancy protects the newborn from whooping cough; the maternal RSV vaccine protects the baby during the first months
- Animal bite: wash the wound with soap and running water for 15 minutes and go to a bite treatment center at once — rabies is almost always fatal once symptoms start; complete every scheduled dose
- Immunosuppressed clients: avoid live vaccines; household members should be fully vaccinated
- IVIG: report headache with stiff neck, reduced urine, leg swelling, or breathlessness after the infusion
Anaphylaxis after a vaccine or IG — the key emergency:
- Call for help; give epinephrine 1 mg/mL IM in the anterolateral thigh immediately — 0.01 mg/kg, maximum 0.5 mg in adults (0.3 mg in children); repeat every 5–15 minutes if needed
- Airway and oxygen; position supine with legs raised (sitting up if breathless); IV fluids for hypotension
- Antihistamines and corticosteroids are adjuncts only; transfer for observation (biphasic reactions)
IVIG reactions — slow or stop the infusion; treat symptoms; for thrombosis or kidney injury, stop and notify the provider.
Administration errors (wrong vaccine or dose, expired product, cold chain breach, live vaccine in pregnancy or immunosuppression) — notify the provider, inform the client, decide on revaccination, and report.
Serum sickness after animal-derived antitoxins — antihistamines and corticosteroids.
- Active immunity = vaccine, slow but lasting; passive = immune globulin, immediate but temporary
- Live vaccines: MMR, varicella, rotavirus, BCG, oral polio, yellow fever, intranasal influenza — not in pregnancy or severe immunodeficiency
- Only universal contraindication: anaphylaxis to a prior dose or component; mild illness is not a contraindication
- Egg allergy is not a contraindication to influenza or MMR vaccine
- Tdap every pregnancy (27–36 weeks); RSV maternal vaccine 32–36 weeks; avoid pregnancy 4 weeks after MMR/varicella
- HBIG + hepatitis B vaccine within 12 hours for infants of HBsAg-positive mothers
- Rabies: wash the wound; category III = RIG into the wound + vaccine (US days 0, 3, 7, 14; WHO/PH intradermal days 0, 3, 7); previously vaccinated = days 0 and 3, no RIG
- TIG for dirty wounds with fewer than 3 or unknown tetanus doses
- IVIG: slow start, hydrate, watch for thrombosis, kidney injury, aseptic meningitis
- Live injectable vaccines: same day or 28 days apart; IG delays MMR/varicella
- Cold chain 2–8 °C; observe 15 minutes; epinephrine ready
- Recombinant zoster (non-live) 2 doses from age 50
Country Notes
United States
- Current schedule: a federal court order of March 16, 2026 stayed all ACIP votes since June 2025 and the January 2026 childhood schedule changes (under appeal), so the pre-2025 CDC recommendations apply — including the universal hepatitis B birth dose within 24 hours and HPV as 2 or 3 doses by starting age. Clesrovimab is FDA-approved, but its ACIP recommendation falls under the stay; nirsevimab and the maternal RSV vaccine remain recommended. Check the current CDC schedule before each clinic session.
- The current Vaccine Information Statement must be given before each dose; adverse events are reported to VAERS; the National Vaccine Injury Compensation Program covers listed vaccines.
Philippines
- The DOH National Immunization Program provides the childhood vaccines (BCG and hepatitis B at birth; pentavalent, OPV, PCV, IPV, MMR) and school-based MR, Td, and HPV; RA 10152 mandates basic immunization for children under 5 and the hepatitis B birth dose within 24 hours.
- Rabies remains endemic. The Anti-Rabies Act (RA 9482) sets up the national rabies program (dog vaccination and registration plus human prevention), and animal bite treatment centers give postexposure prophylaxis, commonly using WHO-recommended intradermal vaccine schedules plus RIG for category III exposures.