Adult Vaccines: Strengthening Immunity

Many people believe that adults do not need vaccinations because they completed their immunization schedule as children. However, there are several reasons why adolescents and adults still require certain vaccines:

Many vaccines received in childhood do not provide lifelong protection. Immunity levels decrease over time, which can lead to infections, particularly in the elderly or those with chronic conditions such as diabetes, heart disease, emphysema, asthma, immunocompromised states, or those who have had their spleen removed.
Adolescents and young adults who never received or completed their vaccinations should use this opportunity to catch up.
Certain infections occur specifically upon entering adolescence, such as the HPV virus transmitted through sexual contact, which is a primary cause of cervical cancer.
New vaccines are now available, such as the HPV vaccine and the Dengue vaccine. These help reduce hospitalizations and mortality rates from vaccine-preventable diseases.

Recommended Vaccines for Adolescents and Adults

Influenza Vaccine: Recommended annually because flu strains change every year. It should be administered once a year before the peak outbreak seasons (rainy and winter seasons in Thailand).
Hepatitis A Vaccine: Transmitted via contaminated food and water. It is highly recommended for those with chronic liver disease, food handlers, or people living in crowded environments. Requires 2 doses (6–12 months apart) for long-term protection, or a single dose for the live-attenuated type.
Hepatitis B Vaccine: Crucial because infected individuals can become chronic carriers, spreading the virus through blood and secretions (sexual contact, mother-to-child, or needle sharing). Chronic infection increases the risk of liver cancer. Requires 3 doses: at month 0, month 1–2, and month 6–12.
Tdap (Diphtheria, Tetanus, and Acellular Pertussis) Vaccine: Adults should receive a 3-dose primary series of tetanus-containing vaccines, with at least one dose being Tdap. A tetanus booster is recommended every 10 years.
Varicella (Chickenpox) Vaccine: For those who never had the disease or the vaccine. Requires 2 doses (4–8 weeks apart). Women of childbearing age should avoid pregnancy for 1 month after vaccination.
Herpes Zoster (Shingles) Vaccine: Recommended for adults aged 60 and older, as they are at the highest risk. Those aged 50–59 may consult a doctor for early vaccination. A single dose provides strong protection for the first 5 years without needing a booster.
HPV Vaccine for Women: Prevents up to 70% of cervical cancers. Recommended for ages 9–45. It is not recommended during pregnancy. Even after vaccination, regular pelvic exams and Pap smears are still necessary.
HPV Vaccine for Men: Prevents anal infections, genital warts, and anal cancer.
MMR (Measles, Mumps, Rubella) Vaccine: Adults who have never had these diseases or completed 2 doses of the vaccine should receive at least one dose. Women of childbearing age should avoid pregnancy for 3 months after vaccination.
Pneumococcal Vaccine: Protects against serious infections in high-risk groups (immunocompromised, those without a spleen, chronic disease patients, and those over 65). Usually starts with one dose of PCV13, followed by PPSV23 at least one year later.

Vaccines for Pregnant Women

Ideally, vaccinations should be completed before pregnancy. However, if a woman is already pregnant and unvaccinated, the following are recommended:

Tdap Vaccine: Protects the mother from Diphtheria and Tetanus, and provides early immunity for the newborn against Pertussis (Whooping Cough) until the baby can get their own shots at 6 months. Best administered during the 27th–36th week of pregnancy. One dose is recommended during every pregnancy.
Influenza Vaccine: Flu can be severe for pregnant women, leading to complications like pneumonia or heart failure. One dose is recommended annually.

Maintaining health through regular exercise, a nutritious diet, and annual check-ups is always better than waiting to fall ill. Vaccines are a vital tool in building your body's defenses against preventable diseases.