Portugal Braces for the Next Pandemic: What Residents Need to Know Now

The Portugal health system navigated the COVID-19 crisis with notable resilience, but six years after the first nationwide lockdown—imposed on March 18, 2020—leading Portuguese virologist Maria João Amorim warns that the threat of another global pandemic remains "highly unpredictable" and inevitable.

Why This Matters

• Vaccine hesitancy is rising in Portugal and across Europe, fueling the resurgence of preventable diseases like measles despite historically high vaccination rates.

• New viral threats including avian flu (H5N1), Nipah virus, and Oropouche are under active surveillance globally, with the World Health Organization confirming that the next pandemic is a question of "when," not "if."

• COVID-19 is now seasonal in Portugal, circulating primarily in autumn, with updated vaccines recommended annually for vulnerable groups—mirroring the flu shot model.

The Scars Left Behind: Long COVID and the Anti-Vaccine Backlash

While the emergency phase of the pandemic has passed, SARS-CoV-2 has become a permanent fixture in Portugal's epidemiological landscape. The virus now behaves as a seasonal respiratory illness, typically peaking in autumn before the annual flu surge. Yet the social and psychological aftermath persists in ways that concern public health experts.

Amorim, a virologist at the Instituto Gulbenkian de Ciência, points to a troubling erosion of trust in vaccination. "There's almost a resentment caused by the pandemic," she explains. Conspiracy theories linking mRNA vaccines to various health problems have proliferated, even as decades of scientific evidence confirm that the cost-benefit ratio of vaccines overwhelmingly favors their use.

The consequences are tangible. Measles cases surged globally in 2024—127,350 cases in Europe alone, the highest since 1997—driven by stagnant vaccination coverage post-pandemic. Portugal recorded just one measles case in 2025, thanks to a 98% coverage rate for the first dose of the measles-mumps-rubella vaccine, but experts warn that pockets of hesitancy among highly educated, affluent parents who seek alternative medicine could erode herd immunity over time.

Polio, once eliminated from Europe, has reappeared in conflict zones and areas with disrupted immunization programs. Even in Portugal, where the National Vaccination Programme (PNV) has been universal and free since 1965, vigilance is required to prevent imported cases.

Long COVID: A Shifting Target

The long-term health consequences of COVID-19 infection—colloquially known as long COVID—remain an evolving puzzle. Amorim notes that different variants produce distinct symptom profiles. Early strains were associated with neurological issues such as loss of smell and taste, extreme fatigue, and brain fog. The Omicron family, which has dominated circulation since late 2021, tends to produce different complications, though research is ongoing.

"Vaccination helps prevent long COVID," Amorim emphasizes, "and that's something we still don't fully understand but is very present."

Current variants circulating in Portugal in 2026—NB.1.8.1 ("Nimbus") and XFG ("Stratus" or "Frankenstein")—are classified as Variants Under Monitoring by the WHO. Both exhibit high transmissibility but have not been linked to increased disease severity or vaccine evasion. Symptoms resemble a severe cold: intense sore throat (often described as "razor-blade throat"), nasal congestion, dry cough, fatigue, headache, and mild fever. The signature loss of taste or smell from earlier waves is now rare.

Portugal's Health System: A Strategic Asset Under Pressure

Portugal's National Health Service (SNS) emerged as a critical asset during the pandemic. Amorim credits it as "an important advantage in how Portugal experienced COVID-19." The SNS provided universal access to testing, treatment, and vaccination—services that fragmented or insurance-based systems struggled to deliver equitably.

Yet the system faces mounting pressure. An excess mortality period began in December 2025, particularly among those over 65, attributed to the dual burden of seasonal flu and cold weather, which exacerbate cardiovascular and metabolic conditions. The Directorate-General of Health (DGS) and the National Institute of Health Doutor Ricardo Jorge (INSA) continue to monitor respiratory virus activity, but the SNS remains chronically underfunded and understaffed.

"It's very important to find strategies to preserve and treat it well," Amorim warns, alluding to ongoing debates over public health investment.

The Next Pandemic: A Question of Time, Not Probability

Amorim is unequivocal: another pandemic is not a matter of if, but when. "There's always the risk of a new pandemic," she says. "Viruses exist abundantly in animals, and there are always contacts that can happen."

Global monitoring systems track several high-risk pathogens in 2026:

• Avian flu (H5N1) has been detected in cattle in the United States and in more than 40 mammalian species. The primary concern is its potential adaptation for efficient human-to-human transmission. Specific vaccines are in development, but seasonal flu shots offer no protection.

• Nipah virus recently caused an outbreak in West Bengal, India, with a 70% fatality rate. The virus, carried by bats, has no treatment and is considered high-risk for pandemic spread.

• Oropouche virus, transmitted by mosquitoes, has expanded beyond the Amazon basin into Central America and the Caribbean. Brazil accounted for 90% of cases in the Americas in 2025. There is no vaccine or specific treatment.

• Mpox (monkeypox) continues to circulate globally with two clades. The more severe clade I was detected outside Africa in 2024, and while vaccines exist, the lack of targeted treatment and the virus's evolution pose ongoing risks.

These threats are amplified by climate change, population growth, intensified human mobility, and ecosystem disruption, all of which facilitate the emergence and spread of pathogens.

Global Preparedness: Lessons Learned and Gaps Remaining

International efforts to prepare for the next pandemic have accelerated. The WHO adopted a Pandemic Accord in May 2025, establishing a comprehensive framework for prevention, preparedness, and response. The WHO's International Pathogen Surveillance Network (IPSN) uses genomic sequencing to detect and respond to disease threats in real time. In 2025 alone, the WHO detected and addressed over 450 public health threats thanks to real-time disease surveillance.

The "100 Days Mission," endorsed by the G7 and G20, aims to develop, test, and authorize emergency use of a new vaccine within 100 days of identifying a novel pathogen—a response time that would have dramatically shortened the COVID-19 crisis.

Portugal's own preparedness is reinforced by the National Health Surveillance Policy (PNVS), updated in March 2026 with the adoption of the "Blue Book of Vaccines" as a new national technical reference. This aims to address demographic, epidemiological, and social challenges and reduce health inequalities.

Despite these advances, global preparedness remains "fragile and unequal," according to health analysts. A troubling phenomenon of "collective amnesia" in some political circles threatens to dismantle surveillance systems and fuel opposition to vaccination. Brazil, for instance, saw over 80% of its population describe the country as poorly or not at all prepared for a new health crisis in a 2026 survey.

What This Means for Residents

For those living in Portugal, the key takeaways are practical:

• Annual vaccination against COVID-19 and flu is recommended for people over 65 and those with comorbidities. The 2025-2026 seasonal campaign, launched in September 2025 and running through April 2026, uses vaccines updated to target the LP.8.1 lineage of SARS-CoV-2.

• Routine childhood vaccinations remain essential. Portugal's 93% polio coverage and 98-99% measles coverage have prevented outbreaks, but declining vaccination rates elsewhere in Europe serve as a warning.

• COVID-19 is not gone. It circulates year-round but peaks in autumn. Symptoms from current variants are milder but can still lead to long-term complications, especially for the unvaccinated.

• The SNS remains a strategic asset but requires sustained investment and public support to maintain its capacity for future crises.

Amorim's assessment is sobering but clear: "We have to accept that these diseases only matter to us when they already affect humans." The viruses circulating in animal reservoirs—bats, birds, pigs—represent an invisible but persistent risk, one that demands continuous vigilance, international cooperation, and public trust in science.

The question is not whether another pandemic will come, but whether the world—and Portugal—will be ready when it does.