Health authorities are urging Filipinos to get their flu shots and double down on respiratory hygiene this October, described by experts as a practical “last chance” window, amid confirmed influenza activity, the onset of cool Amihan winds, and mass mobility for Undas that will soon give way to packed Christmas gatherings.
According to the Department of Health (DOH), surveillance recorded 6,457 influenza-like illness (ILI) cases from Sept. 28 to Oct. 11, 2025, lower than the same two-week period in 2024, but the agency stresses the country remains in flu season.
Meanwhile, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) formally declared the start of the Northeast Monsoon (Amihan) on Oct. 27, 2025, bringing cooler, drier air that favors indoor crowding.
On the transport front, the Philippine Ports Authority (PPA) expects about 2.2 million sea passengers to pass through seaports nationwide during the Undas period, an increase from last year, underscoring crowding risks in terminals and vessels.
Furthermore, a new CDC Morbidity and Mortality Weekly Report suggests this season’s flu vaccines can cut the risk of influenza-related clinic visits and hospitalizations by about half, strengthening the case for getting vaccinated before holiday mixing peaks.
Why October Matters
Vaccinating in October gives immune protection time to build before Undas travel, school fairs, office parties, and Simbang Gabi compress people into enclosed spaces.
Globally and regionally, influenza in tropical and subtropical Asia, including the Philippines, shows non-winter-only patterns, with peaks commonly from May/June to October and, in some settings, a second bump December–February.
This long-standing seasonality evidence remains a practical guide for timing campaigns in tropical climates and directly supports the push to act now rather than wait for December.
Meanwhile, meteorology is lining up with behavior change. In a PAGASA press release signed Oct. 27, the agency said observations “indicate the start of the Northeast Monsoon (Amihan) season,” adding that Amihan is expected “to be more dominant in most areas of the country, bringing cool and dry air and episodes of cold temperature surges.” Cooler, drier air and more time indoors are classic conditions for easier respiratory virus spread, another reason timing matters now.
The Philippine situation right now
Based on a DOH surveillance update, ILI cases fell 25% over the two weeks ending Oct. 11, with 6,457 cases logged versus 8,628 in the comparable 2024 period.
Nevertheless, the agency emphasized that the country is in flu season and rolled out “Trangkaso Bye-Bye!” reminders on handwashing, rest, nutrition, staying home when ill, and masking when symptomatic.
Health Secretary Teodoro Herbosa has repeatedly clarified the national picture. “Wala pong any type of outbreak na ILI; it’s the seasonal flu, and we still have to be careful,” he said, stressing that the current rise fits the typical “-ber months” trend and that outbreak thresholds have not been reached.
Meanwhile, clinical networks in Metro Manila continue to watch laboratory trends. The Philippine Society for Microbiology and Infectious Diseases (PSMID) reported a 22% month-on-month rise in October and a high test-positivity rate around 42%, indicating ongoing community transmission as crowds build up.
Furthermore, PSMID reiterated standard preventive steps—vaccination, frequent handwashing, masking when symptomatic, and cough etiquette.
On the other hand, Herbosa has also knocked down misinformation about drastic restrictions. “There is no planned lockdown, that is fake news… What we have is the seasonal respiratory illnesses… We do not have a flu outbreak,” he said, urging the public to take common-sense precautions instead.
The science on protection: what to expect this season
Globally, a reliable early indicator for Northern-Hemisphere countries comes from the Southern Hemisphere season. In September 2025, the CDC’s MMWR published interim vaccine-effectiveness (VE) estimates pooling data from eight Southern Hemisphere countries.
According to the report, seasonal influenza vaccination reduced outpatient visits by 50.4% and hospitalizations by 49.7% for any influenza virus detected during March–September 2025. Moreover, VE against hospitalization due to predominant A(H1N1)pdm09 was 41.6%—still a meaningful layer of protection.
The CDC also noted that the 2025–26 Northern Hemisphere vaccine composition is aligned with Southern Hemisphere strains, implying similar protection here if the same viruses circulate, another reason to vaccinate before the November–December social calendar accelerates.
Furthermore, updated syntheses on seasonality underscore why “October now” is better than “December later” in the Philippines: tropical settings can have year-round circulation with distinct spikes, unlike strictly winter-bound curves in temperate zones. WHO-linked analyses and recent systematic reviews continue to map these patterns across tropical and subtropical Asia.
Undas mobility and crowding risks
As families plan cemetery visits and provincial trips, transport agencies anticipate the crush. The PPA projects ~2.2 million sea passengers nationwide for Undas 2025 (Oct. 27–Nov. 5), higher than 1.9 million last year.
“Suspendido rin ang lahat ng leave ng mga kawani…” and “Nakahanda rin ang Malasakit Help Desk na bukas 24/7…” the PPA chief added, framing a whole-of-agency surge to keep flows orderly.
Nevertheless, infection prevention inside terminals and vessels still hinges on individual and community behavior—particularly vaccination, hand hygiene, masking when symptomatic, and staying home when febrile.
Moreover, the PPA flagged historically busy ports—Iloilo, Jordan (Guimaras), Batangas, Calapan, and BREDCO (Bacolod), where high volumes funnel through tight queues and boarding areas. Meanwhile, DOTr and the Coast Guard maintain 24/7 Malasakit Help Desks and coordination posts as part of Oplan Biyaheng Ayos: Undas 2025.
Who should prioritize vaccination, and why now
DOH guidance and hospital advisories highlight high-risk groups: older adults, young children, pregnant people, and individuals with chronic heart, lung, kidney, or metabolic disease, who face higher odds of pneumonia, severe disease, or hospitalization.
Timing is the quiet determinant: immunity builds roughly two weeks after vaccination, so October shots maximize protection before reunions, office parties, and Simbang Gabi intensify contacts.
Meanwhile, infectious-disease experts continue to stress that a seasonal uptick is expected—and manageable—if prevention is taken seriously. “Normal itong pagtaas ng influenza-like illness…” Dr. Rontgene Solante said in a DZRH interview, explaining that ILI symptoms overlap and can be caused by several respiratory viruses, which is why general precautions (including vaccination) matter each “-ber” season.
Access and cost: what PhilHealth covers when cases worsen
On the financing side, PhilHealth introduced the Outpatient Emergency Care Benefit (OECB) through Circular No. 2024-0033, effective Feb. 14, 2025, providing coverage for outpatient emergency cases managed in accredited hospital emergency departments. The OECB serves as a new backstop when respiratory infections suddenly worsen but do not lead to admission.
Furthermore, the OECB complements existing All Case Rate packages, searchable by ICD-10 on PhilHealth’s website, which include case rates for influenza and pneumonia. Members are advised to bring valid identification and ensure their membership data are updated to avoid delays in claims processing.
Prevention that works in crowded months
The DOH’s message has been consistent: get vaccinated, wash hands thoroughly, mask if you have coughs or colds, improve airflow at home and during gatherings, and stay home when febrile. “It’s our ILIs, talagang dumarami ’yan… Wala pong any type of outbreak na ILI; it’s the seasonal flu, and we still have to be careful,” Herbosa said, urging practical steps over panic.
Meanwhile, organizers of barangay events, school programs, parish activities, and transport operations can reinforce these habits through posters, PA reminders, and consistent peer-to-peer cues that normalize staying home when sick.
Furthermore, for elders and those with comorbidities, families can schedule vaccination days before All Saints’ and All Souls’ Days to ensure protection ahead of travel and church visits.
Snapshots on the ground
Metro Manila clinical signal: Positivity above 40%. Across tertiary hospitals in NCR, PSMID tracked a 22% increase in October and a ~42% positivity rate—signs of active community transmission even as national totals remain below outbreak thresholds. The society again urged vaccination, handwashing, and masking while symptomatic.
Transport chokepoints: Ports brace for Undas. The PPA projects 2.2 million passengers nationwide during the Undas period and has named Iloilo, Jordan (Guimaras), Batangas, Calapan, and BREDCO (Bacolod) among the busiest ports, where staff are on full deployment and Malasakit Help Desks operate 24/7. On the other hand, even with crowd-management plans, infection risk rises in long queues and enclosed terminals—another reason to vaccinate before traveling.
Weather shift: Amihan confirmed. PAGASA’s notice on Oct. 27 said the “start of the Northeast Monsoon (Amihan) season” is underway and forecast successive surges over the next two weeks, conditions that typically bring cooler air, nudge activities indoors, and, for Northern Luzon, sometimes rough seas.
What this means for October—and for December tables
According to DOH surveillance, ILI cases dipped versus last year during early October; nevertheless, the country remains in flu season, and laboratory signals in the NCR show elevated positivity that often precedes more clinic visits.
Meanwhile, Amihan’s arrival is settled science, bringing the cool, dry air that usually pushes people indoors.
Furthermore, Undas mobility will funnel millions through transport hubs—conditions that favor respiratory virus transmission before the December party calendar fully ramps up.
Based on the CDC’s Southern Hemisphere analysis, getting vaccinated now can halve a person’s risk of an influenza-related clinic visit or hospitalization, protection that carries into November–December gatherings.
On the other hand, postponing shots until late in the season narrows that protective window, especially for grandparents, toddlers, pregnant family members, and people living with heart, lung, kidney, or metabolic conditions.
What communities can do, without delay
Local governments, schools, parishes, and transport operators can align messages with verified guidance. Barangays and parishes can host weekend vaccination days in halls and church grounds before Undas travel peaks.
Meanwhile, terminals, cemeteries, and markets can post hand-hygiene and cough-etiquette visuals and remind the public to mask when ill and stay home if febrile.
Furthermore, LGUs can publicize PhilHealth’s OECB and case-rate coverage so families know cost should not deter early care. Lastly, peer-to-peer campaigns, student councils, parish ministries, workplace committees, can normalize staying home when sick and checking on lolo and lola to ensure they’ve had their flu shots.
The flu, often dismissed as ordinary, is a mirror held up to how seriously a society values prevention. Each October offers a quiet test: whether Filipinos choose to be proactive or reactive, to arm themselves with a small shot today rather than gamble with an empty chair at the family table in December.
In a country where family gatherings define the holidays, prevention becomes an act of love, not merely policy.
The lesson, therefore, is simple but enduring: timing saves lives. The decision to get vaccinated before the Amihan winds fully settle could mean a Christmas without the shadow of hospital corridors.
Ultimately, flu prevention is not just about avoiding sickness; it is about protecting traditions, keeping grandparents healthy, and ensuring every family member makes it home for Noche Buena.
As public-health officials remind us, and as the data affirm, one shot in October can preserve a season of togetherness in December.
