Vaccination to prevent infectious diseases in adults and the elderly, or those with chronic medical conditions, is becoming increasingly important. Vaccines help reduce the risk of infections or reduce hospitalizations. The schedule for administering vaccines for each specific infection is agedependent, and each vaccine has its own program with designated vaccination times. It is crucial to follow the schedule and ensure all doses are administered as recommended. 

Recommended Vaccines for the Elderly: Types, Doses, Benefits, and Side Effects 

1. Influenza Vaccine (4 Strains) 

Although influenza can occur at any age and often resolves within 3–5 days in healthy individuals, it can cause serious complications in the elderly or those with chronic conditions (e.g., COPD, asthma, heart disease, stroke, kidney disease, diabetes). These patients are at higher risk for hospitalization and death.

Recommendation:

• All seniors should receive 1 dose annually, especially before flu season (typically during the rainy and winter seasons in Thailand).
• The Flu High-Dose vaccine is specifically designed for people aged 65 and older, with 24% increased effectiveness compared to the standard dose.

Flu strains for 2024 (Southern Hemisphere):

• A/Victoria/4897/2022 (H1N1)-like virus
• A/Thailand/8/2022 (H3N2)-like virus
• B/Austria/1359417/2021 (B/Victoria lineage)-like virus
• B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

Possible side effects: Mild fever, injection site soreness, fatigue

2. Pneumococcal Vaccine (for Pneumonia Prevention) 

The Streptococcus pneumoniae bacterium is a common cause of severe pneumonia in the elderly. It can also lead to blood infections, meningitis, ear infections, sinusitis, and even death or disability.

Types of Pneumococcal Vaccines:

• PCV13 (13-valent conjugate)
• PCV15 (15-valent conjugate) – covers 2 more strains than PCV13
• PPSV23 (23-valent polysaccharide) – provides broader coverage including severe strains

Recommendation:

• For individuals aged 65+, immunocompromised patients, or those with chronic diseases.
• Typically, a conjugate vaccine (PCV13 or PCV15) is given first, followed by PPSV23 one year later.

Possible side effects: Swelling/pain at injection site, mild fever

3. Herpes Zoster Vaccine (Shingles Vaccine) 

Shingles is caused by the VZV (varicella-zoster virus), which remains dormant in nerve tissue after chickenpox. When immunity decreases (due to aging, stress, or illness), the virus can reactivate, causing painful rashes. Even after the rash heals, nerve pain may persist for months or years.

Recommendation:

• For adults aged 50 and older
• 2 doses of 0.5 mL each, injected into the muscle, spaced 2–6 months apart
• Strongly advised for people with low immunity, chronic illness, or HIV
• The newer recombinant zoster vaccine provides over 90% effectiveness

Possible side effects: Arm pain, low-grade fever, fatigue

4. RSV Vaccine (Respiratory Syncytial Virus) 

RSV typically affects young children but can also cause severe respiratory illness in seniors and immunocompromised individuals.

Symptoms of RSV in older adults:

• Fever
• Persistent cough
• Shortness of breath
• Wheezing or rapid breathing
• Fatigue
• Increased mucus production

Recommendation:

• Arexvy is the current vaccine recommended for seniors aged 60+, especially those aged 75+ or with chronic lung, heart disease, or obesity (BMI >90 kg/m²)
• 1 dose recommended, and should be given at least 2 weeks apart from other vaccines

Important notes:

• Observe for allergic reactions or fainting after injection
• Postpone vaccination in cases of high fever or acute illness, but mild infections (like colds) are not a contraindication
• Consult a physician to assess personal risk and vaccine suitability before receiving the shot Possible side effects: Injection site pain, mild fever, dizziness, anxiety-related reactions

General Guidelines for Seniors Before Vaccination

• Avoid vaccination if feeling unwell or having a high fever
• Always inform the doctor of allergies, current medications, or chronic conditions
• Stay under observation for 15–30 minutes after the injection for safety