The Quadrivalent (DPT-IPV) vaccine is mandatory for children, but do you assume “adults no longer need a booster shot”? If so, this is a major mistake. Especially, immunity against Tetanus wanes after about 10 years, and an infection from soil or a wound can be life-threatening for adults, with a mortality rate of 10%∼50%.
However, the question of whether you need to be boosted for “all components” is usually “overkill.”
Necessity List for Adult Booster Shots of the Quadrivalent Vaccine (DPT-IPV) (2025 Latest Summary)
| Vaccine Component | Do Adults Need a Booster? | Reason / Recommendation Level (As of 2025) |
| Tetanus (T) | ◎ Absolutely needed (Every 10 years) | The bacteria is found in soil and causes death in 10%∼50% of cases. 50-100 cases annually in Japan (2024). → The global standard is one booster shot of Td (Tetanus + Diphtheria) or a standalone T every 10 years. |
| Diphtheria (D) | ○ Recommended (Especially for overseas travel) | Nearly eradicated in Japan, but currently prevalent overseas (Southeast Asia, Russia, etc.). → Covered by the Td booster every 10 years. |
| Pertussis (P) | △ Depends on the situation | Adults typically only suffer from a “2-month persistent cough,” but can cause severe illness/death in infants. → Pregnant women, families of newborns, nursery staff, and medical personnel are recommended to get one booster of Tdap (Tetanus + Diphtheria + Acellular Pertussis). |
| Polio (IPV) | × Generally unnecessary | Japan switched to the inactivated vaccine in 2012. The 4 childhood doses provide near-lifelong immunity. |
2025 Ranking: Which Vaccines Should Adults Actually Get?
| Rank | Target Group | Recommended Vaccine | Estimated Cost (Self-pay) |
| 1st | Those who often step on injuries, work with soil, construction workers. | Tetanus (T) standalone or Td | ¥3,000 ∼ ¥6,000 |
| 2nd | Travelers to Southeast Asia, India, Russia. | Td (Diphtheria + Tetanus) | ¥4,000 ∼ ¥8,000 |
| 3rd | Pregnant women, families of babies under 3 months old. | Tdap (Pertussis-containing) | ¥8,000 ∼ ¥12,000 |
| 4th | Nursery staff, pediatricians, grandparents. | Tdap (1 additional dose) | ¥8,000 ∼ ¥12,000 |
| 5th | Ordinary adults not boosted for over 10 years. | Td (Every 10 years) | ¥4,000 ∼ ¥8,000 |
Easily Available Adult Vaccines in Japan (2025)
| Product Name | Components | Average Price (Self-pay) |
| Adacel | Tdap (Tetanus + Diphtheria + Pertussis) | ¥9,000 ∼ ¥12,000 |
| Boostrix | Same as above | ¥9,000 ∼ ¥12,000 |
| Tetanol | Tetanus standalone | ¥3,000 ∼ ¥5,000 |
| Diphtheria Booster | Td (Diphtheria + Tetanus) | ¥4,000 ∼ ¥7,000 |
Summary
Most adults only need the Tetanus booster every 10 years. → Pregnant families, nursery staff, and overseas travelers should get the Pertussis-containing (Tdap) booster once. → Polio and Diphtheria provide near-lifelong immunity from the 4 childhood doses.
“No need for any shots as an adult” is wrong, but “boosting all components” is also overkill. Seriously, don’t forget the Tetanus booster every 10 years.
At-Home Testing Kit Ranking (Combined COVID-19 and Influenza)
Here is the English translation of the ranking table for at-home diagnostic kits that test for both COVID-19 and Influenza A/B:
| Rank | Product Name (Manufacturer) | Targets Detected | Sensitivity (Detection Rate) (Estimate: 12-48h Post-Onset) | Result Time | Approximate Price (Per Test) | Suitability for Pregnant Women / Children | Key Features & Availability |
| 1 | Panbio COVID-19/Flu A&B | COVID + Flu A/B | COVID: Approx. 90% | Flu: Approx. 85% | 15 mins | ¥1,980 – ¥2,480 | ◎ (Shallow Nasal Swab) |
| 2 | クイックナビ-Flu+COVID | Same (COVID + Flu A/B) | COVID: 88% | Flu: 80–85% | 15–20 mins | ¥1,780 – ¥2,200 | ◎ (Designed for children’s use) |
| 3 | KBMラインチェック nCoV/Flu | Same (COVID + Flu A/B) | COVID: 85% | Flu: Approx. 80% | 15 mins | ¥1,480 – ¥1,980 | ◎ |
| 4 | イージードック Flu＆COVID-19 | Same (COVID + Flu A/B) | COVID: 87% | Flu: 82% | 15 mins | ¥2,200 – ¥2,600 | ◎ (Many cases of use by pregnant women) |
