MANAGEMENT OF VACCINATIONS FOR ADULTS

With new vaccines becoming available and existing ones being updated, it is not always clear which vaccinations are recommended, how often they should be repeated, what side effects may occur, or whether they interact with certain medical conditions or medications.

In the article below, our family doctors outline the vaccines most commonly recommended for adults in Thailand.

Members can discuss their vaccination plan with their family doctor, for example during their annual check-up. Additional vaccines (e.g., Hepatitis A/B, RSV, Varicella, HPV, COVID-19) may be advised depending on individual circumstances. Vaccinations are recorded in each member’s medical file for future reference.

Vaccinations for Adults – The Main Essential Vaccines Recommended in Thailand

Note: Global opinions about vaccines differ and regularly change with evolving insights through new developments and research. The below article is a “best effort” to summarize our recommendations based on our current knowledge and experience.

1. Influenza vaccine
   Influenza is a highly contagious virus that spreads through droplets and close contact. Symptoms range from minor (fever, cough, runny nose, body aches, fatigue) to severe (pneumonia and respiratory failure). Seasonal vaccines can help reduce the rate of infection and prevent serious illness for those infected.In Thailand, the epidemic season starts in June and continues to November. Vaccination for the Southern Hemisphere is best administered around April/May. It is recommended for children, adults over 60, and patients of all ages with underlying diseases.Common side effects include mild pain, redness, or swelling at the injection site, as well as fever, headache, muscle aches, and tiredness. These effects are uncommon, generally mild, and resolve within a day or two.

   The influenza vaccine should be repeated annually.

   Note: In Europe and North America, the flu season runs from November to March, and sometimes a different “cocktail” of strains is used for the Northern Hemisphere. Administration is advised around October.

2. Pneumococcal vaccine
   Pneumonia is a bacterial infection caused by Streptococcus pneumoniae. It can range from minor sinus infections to more serious conditions such as middle ear infections (hearing loss and fever), bacterial pneumonia (fever, cough, chest pain, shortness of breath), or brain and spinal cord infections (high fever, headache, nausea, vomiting, stiff neck, and coma).High-risk groups include people aged 60 and over and those with underlying medical conditions.Two types of pneumococcal vaccines are available in Thailand, covering different bacteria:

• • Pneumococcal conjugate vaccine (PCV10, PCV13, PCV15, PCV20) – recommended for children and certain adult groups.
  • Pneumococcal polysaccharide vaccine (PPSV23) – mainly recommended for adults.

These vaccines can be combined but not given at the same time. If combined, the conjugate vaccine should be administered before the polysaccharide vaccine.
Side effects: Serious side effects are rare; mild soreness, redness, or swelling at the injection site is not uncommon.

Once fully vaccinated, protection is generally long-term, though some may need repeat doses.
Please consult your family doctor for a personalized vaccination plan.

3. Zoster vaccine (shingles)
   In Thailand, the Shingrix vaccine helps prevent shingles — a painful rash and potential infections of the eyes and nervous system caused by the varicella-zoster virus.
   It is a non-live, recombinant subunit vaccine, highly effective in preventing shingles and postherpetic neuralgia (PHN).
   It is recommended for:

• • Adults 50 years and older.
  • Adults 18+ with weakened immune systems.
    It is given in two doses: 2–6 months apart for most, 1–2 months apart for those immunocompromised.
    Side effects: Serious side effects are rare; mild soreness, redness, or swelling at the injection site may occur.

4. Tetanus vaccine
   Tetanus is a serious bacterial disease affecting the nervous system and muscles, caused by Clostridium tetani. Found in soil and animal/human feces, bacteria usually enter the body via puncture wounds.Early symptoms include twitching of the jaw (“lockjaw”), stiff neck, and difficulty swallowing, followed by fever, sweating, high blood pressure, and rapid heart rate. Twitching and spasms can persist for weeks, with recovery taking months in severe cases.The vaccine is 100% effective when fully administered. For deep or contaminated wounds, the first shot should be given within 48 hours, followed by a second dose after 1 month and a third dose after 6 months.

   Booster shots are recommended every 10 years after completing the primary series.

5. Rabies vaccine
   Rabies is a fatal virus transmitted via the saliva of infected animals, primarily through bites. Symptoms may not appear immediately, but within weeks can progress from fever and irritability to seizures, hallucinations, paralysis, and death.Stray dogs and cats in Thailand are common sources of rabies.Fortunately, vaccination is 100% effective when properly administered.

   Two types of vaccines:

• • Pre-exposure prophylaxis – for those in regular contact with animals. Three doses (days 1, 3, 7), with boosters based on risk.
  • Post-exposure prophylaxis – administered after exposure. Five doses (days 1, 3, 7, 14, 28), with boosters if repeated incidents occur.
    Side effects: Rare, usually mild soreness at the injection site.

6. Dengue vaccine
   Dengue fever, transmitted by Aedes mosquitoes, is common in Thailand. Symptoms vary widely, from mild fever to severe abdominal pain, shock, and even death.
   The first dengue vaccine (Dengvaxia), introduced 25 years ago, was only recommended for people previously infected.The newer Qdenga vaccine has shown effectiveness in preventing dengue and reducing hospitalizations, though studies are ongoing.
   Opinions differ:

• • WHO recommends Qdenga only for children aged 6–16 in high-risk areas.
  • Some authorities recommend it for people up to 60 years old.
    Be Well advises:
  • Those who have not had dengue before are advised to wait for more research results, although persons under 60 years of age living in high-risk areas could consider vaccination.
  • Anyone (any age) who has had dengue and lives in or travels to risk areas should vaccinate (at least 6 months after infection), as a second infection poses greater risks. Testing is available if unsure about past infection.
    Qdenga is given in two doses, three months apart.
    Side effects: Rare, typically mild soreness at the injection site.