“When is the most effective time to get the influenza vaccination?”
It is generally said that antibodies begin to form about two weeks after the influenza vaccination, and the protective effect lasts for about five months. Therefore, it is crucial to determine the timing so that the antibody level in your body reaches its peak just as the influenza season begins in Japan, typically from late December to March.
Complete Summary: When is the Best Time for an Influenza Vaccination?
| Item | Best Timing | Reason |
| Strongest Timing in Japan | Mid-October to End of November | Peak epidemic is late December to March → Antibody levels will be at their maximum during this period. |
| Absolute Deadline | By December 15th | Getting it later significantly increases the chance of missing the peak of the epidemic. |
| Too Early Line | Before September | Antibodies will largely disappear by May–June (Effectiveness is halved). |
| Still OK Line (Too Late) | January to February | Still worth getting the shot if the epidemic is ongoing. |
Monthly Recommendation Level
| Month | Recommendation | Comment |
| September | ★☆☆☆☆ | Too early. The effect will be almost zero by next May. |
| Early October | ★★★☆☆ | A bit early (More suitable for healthcare workers/the elderly). |
| Mid-October to End of November | ★★★★★ | The Strongest Zone! Everyone should aim for this time! |
| Early December | ★★★★☆ | Still on time. |
| Mid-December to January | ★★★☆☆ | The epidemic may have started, but it’s still worth getting the shot. |
| Post-February | ★★☆☆☆ | Late, but OK if the epidemic is still ongoing this year. |
Best Timing by Age Group
| Target Group | Optimal Period | Rationale |
| Children (Especially under 13, 2 doses) | Mid-October to Mid-November | Ideal: 1st dose late Oct, 2nd dose late Nov. |
| Elderly (65 and over) | Early October to Mid-November | Priority vaccination period available + can be vaccinated earlier. |
| Pregnant Women | October to December | OK anytime, but ideally before the peak season (Timing depends on gestation). |
| Healthcare Workers / Nursery Staff | Early to Mid-October | Often mandatory at work. |
| General Adults (Healthy) | November 1st to 30th | Less crowded + Antibody peak aligns perfectly with the epidemic. |
Scheduled Start Dates (Estimate)
| Target Group | Start Date |
| Elderly (65 and over) | October 1st |
| Healthcare Workers | October 1st |
| General Public (Children to 64) | October 15th (Varies by clinic) |
Conclusion
“You can’t go wrong if you get vaccinated in November!”
→ October is a bit early, and December is a bit late. → November is the strongest Golden Month!
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) |
