Chikungunya: Where It Is Spreading, How It Differs From Dengue and Where the Vaccine Stands

In July 2025, a city of nine million people in southern China began asking residents to tip out every saucer under every potted plant. Within weeks, local health workers had logged thousands of chikungunya cases in a place that had never seen a large outbreak before. The same summer, France recorded its highest-ever number of locally acquired infections, and the World Health Organization warned that the pattern looked uncomfortably like the 2004 epidemic that eventually reached millions of people.

Then the chikungunya vaccine story turned. On 22 August 2025 the US Food and Drug Administration suspended the license of the first-approved vaccine after reports of serious reactions in older adults, leaving a newer, non-live vaccine as the only US option. As of late 2025, searches for the vaccine have spiked alongside searches for the disease itself.

This piece sorts out what is known: where the virus is moving, how to tell it from dengue, and what the vaccine evidence does and does not show.

What changed recently with the chikungunya vaccine: a dated timeline

Two years ago there was no licensed chikungunya vaccine anywhere. Today there are two, and one of them has already been pulled from the US market. The sequence matters, because much of what circulates online mixes up events from different months.

• November 2023: The FDA granted accelerated approval to a live-attenuated vaccine (marketed as Ixchiq) for adults 18 and older at increased risk of exposure. Approval rested on antibody responses rather than proof that it prevented illness.
• 2024: CDC published travel-based recommendations for that vaccine; the European Union authorized it in June 2024.
• February 2025: The FDA approved a second vaccine built from virus-like particles (marketed as Vimkunya) for people 12 and older. European regulators followed within weeks.
• April to May 2025: After reports of hospitalizations and a small number of deaths in vaccinated adults in their 60s to 80s, most with underlying conditions, US advisers added a precaution for older adults, then the FDA and CDC recommended pausing the live vaccine in people 60 and over. European regulators imposed a temporary restriction in those 65 and older, which they later lifted in July with a call for case-by-case assessment.
• July 2025: WHO cautioned that roughly 5.6 billion people in 119 countries live where the transmitting mosquitoes occur, and flagged the Indian Ocean and southern China outbreaks.
• 22 August 2025: The FDA suspended the live vaccine’s US license. CDC updated its guidance to reflect that only the virus-like particle vaccine is available in the United States.

The upshot for a US reader is simple to state and hard to have predicted a year ago: the vaccine most articles from 2024 describe is not the one a clinician here can offer. Outside the US, both products remain authorized in several countries, with the live vaccine carrying age-specific cautions. Check the CDC page listed in our references for the current position before assuming anything else you read is up to date.

What chikungunya actually is, and why the name tells you the main symptom

The word comes from the Kimakonde language of the Makonde people of southern Tanzania and northern Mozambique, where the virus was first identified in 1952. It translates roughly as “that which bends up,” a description of the stooped posture of people whose joints hurt too much to straighten. Sixty-odd years later, that is still the most useful thing to remember about the disease.

Chikungunya is an arbovirus, meaning a virus carried between people by biting arthropods, in this case mosquitoes. It belongs to the alphavirus family, a different branch from dengue and Zika, which are flaviviruses. Two mosquito species do almost all the work: Aedes aegypti, the yellow fever mosquito that thrives in tropical cities, and Aedes albopictus, the Asian tiger mosquito, which tolerates cooler weather and has settled across southern Europe and much of the eastern United States. Both bite mainly by day, with peaks in the early morning and late afternoon, which is why bed nets alone do little.

Illness typically starts three to seven days after a bite, though the range is two to twelve. Fever arrives fast, often above 39°C (102°F), together with joint pain that is usually on both sides of the body and concentrated in the small joints of the hands, wrists, ankles and feet. Headache, muscle aches, a blotchy rash and fatigue are common. Unlike dengue, where perhaps only one infection in four causes noticeable symptoms, CDC estimates that around three in four people infected with chikungunya become ill. That high attack rate is one reason outbreaks are so visible: when the virus reaches a new town, a large fraction of the exposed population feels it within the same fortnight.

There is no antiviral treatment. Care is supportive, which in plain terms means rest, fluids and pain relief chosen by a clinician once dengue has been considered. Deaths are rare and cluster in newborns, older adults and people with chronic illness.

Where is chikungunya spreading in 2025?

The map has been redrawn in three places this year, and each tells a slightly different story about how the virus moves.

The first is the Indian Ocean. Beginning in late 2024 and accelerating through the first half of 2025, La Réunion recorded tens of thousands of cases, with spillover to Mayotte, Mauritius and neighboring islands. For epidemiologists this was an echo of 2004 to 2006, when the virus jumped from coastal Kenya to the same islands and then to India, where an estimated 1.3 million people fell ill in a single year. Islands with dense Aedes populations and little prior immunity are the virus’s ideal launch pad.

The second is China. In July 2025 the city of Foshan in Guangdong province reported an outbreak that quickly passed several thousand confirmed cases, the largest ever recorded in the country. It was seeded by an imported case and amplified by a hot, wet summer and abundant tiger mosquitoes. Local authorities responded with mass larval-source clearance, the same low-tech method that ended the 2007 outbreak in northern Italy.

The third is Europe. France logged a record number of locally acquired, or autochthonous, cases in the summer of 2025, meaning infections in people who had not traveled. Italy reported clusters too. This is the piece of the story that unsettles public health planners most: Aedes albopictus is now established across the Mediterranean and creeping north, and each returning traveler carrying the virus in their blood is a potential spark.

South Asia and the Americas remain the largest steady reservoirs. Brazil and Bolivia have reported substantial case counts in 2025, and the virus has circulated in the Americas continuously since arriving in the Caribbean in 2013. In the mainland United States, no locally acquired cases have been reported since 2015; all recent US cases have been in travelers. WHO’s July 2025 estimate that 5.6 billion people live in at-risk areas of 119 countries reflects where the mosquitoes are, not where outbreaks are happening now, but it is a fair statement of the ceiling.

Chikungunya vs dengue symptoms: how to tell them apart

The two infections share the same mosquitoes, the same neighborhoods and the same first 48 hours: abrupt fever, headache, aching body, sometimes a rash. Clinicians in outbreak zones frequently cannot separate them at the bedside, which is why laboratory testing matters and why some advice applies until dengue is ruled out. A few clues do help.

Feature	Chikungunya	Dengue
Virus family	Alphavirus	Flavivirus (four serotypes)
Share of infections with symptoms	About 3 in 4	About 1 in 4
Fever	High, sudden, usually 2 to 3 days	High, sudden, often 2 to 7 days
Dominant complaint	Severe, symmetric joint pain, often small joints	Deep muscle and bone pain, pain behind the eyes
Joint pain lasting months	Common	Uncommon
Bleeding, plasma leakage, shock	Rare	Defining features of severe dengue
Low platelet count	Mild, if present	Often marked
Deaths	Rare; newborns, older adults	Higher; severe dengue can be fatal without hospital care
Immunity after infection	Thought to be long-lasting	Only to that serotype; second infection can be worse

The single most important practical difference is what can go wrong. Dengue has a recognizable danger window, usually as the fever drops around day three to seven, when a minority of patients develop plasma leakage, bleeding or shock. WHO lists warning signs including severe abdominal pain, persistent vomiting, bleeding from the gums or nose, blood in vomit or stool, rapid breathing and marked restlessness or lethargy. Chikungunya rarely does this. Its burden is measured in weeks of hobbling rather than emergency admissions.

Because a dengue patient’s platelets can fall, CDC and WHO advise clinicians to steer away from aspirin and non-steroidal anti-inflammatory drugs until dengue has been excluded. That is a clinician’s call, not a home decision, but it explains why a doctor may ask you to hold off on a familiar pain reliever for a few days.

Testing settles the question. A molecular test (RT-PCR, which detects the virus’s genetic material) works in the first week; antibody tests (IgM, the early antibody your immune system makes) become positive after that.

How long does chikungunya last? The joint-pain question nobody likes answering

The honest answer has two parts, and the second one is why chikungunya earns its reputation.

The acute phase is short. Fever usually breaks within two to three days, and most people feel substantially better within a week to ten days. The rash fades, the headache lifts, appetite returns. If that were the whole story, chikungunya would be a footnote among travel infections.

The second phase is the joint pain that lingers. In follow-up studies, a meaningful share of patients still report pain, stiffness or swelling at three months, and a smaller share at one year or beyond. Estimates vary widely between outbreaks and study methods, from well under a fifth of patients to more than half at the three-month mark, and the figure tends to be higher in older adults and in people who had joint problems before infection. Cleveland Clinic and NHS both describe joint pain persisting for months in some patients, and a small minority develop a chronic inflammatory arthritis that can resemble rheumatoid arthritis on examination.

Why does this happen? The virus has a particular fondness for the lining of joints and for muscle tissue, and studies have found viral material and immune-cell activity persisting in these tissues well after it has cleared from the blood. Whether the ongoing pain reflects hidden virus, a misfiring immune response, or damage sustained during the acute phase is still debated. What is not debated is that patients describe it vividly: wrists that will not support a kettle, ankles that seize after sitting, a morning routine that takes twice as long.

Management of this phase belongs with a clinician, and increasingly with rheumatologists in places that have seen large outbreaks. The pattern usually improves over time; most people are markedly better by the end of the first year. Anyone whose joint pain is worsening rather than easing, or who develops new hot, swollen joints months later, should be assessed rather than assume it is “just chikungunya.”

Who is most likely to become seriously ill

Chikungunya is often described as painful but rarely dangerous, and for a healthy 35-year-old that is accurate. The risk profile is different at the two ends of life and in people whose bodies are already under strain.

Newborns are the group clinicians worry about most. A pregnant person who is viremic, meaning the virus is circulating in their blood, in the days around delivery can pass it to the baby during birth. Infected newborns can develop fever, feeding difficulties, rash, swelling of the limbs and, in severe cases, brain inflammation. Infection earlier in pregnancy rarely reaches the fetus, and there is no established link to birth defects, which is a point worth stating plainly given the confusion with Zika. Because of the delivery-window risk, CDC advises that pregnant travelers near term think carefully before visiting an active outbreak area.

Adults over 65 are the second group. Fatal cases during the Réunion and Indian outbreaks were concentrated in older people, often with heart disease, diabetes, kidney disease or high blood pressure. The mechanism is usually decompensation of the existing condition rather than the virus attacking a new organ: a high fever and days of poor fluid intake are hard on a heart that was already working at its limit. Older adults are also the group most likely to be left with long-term joint pain.

Chronic illness in any age group raises risk in the same way, and people with weakened immune systems may clear the virus more slowly. Rare complications reported in the literature include inflammation of the heart muscle, the eye and the nervous system, including Guillain-Barré syndrome, but these are exceptional.

The pattern shapes the vaccine debate. The people who would benefit most from protection are precisely the older adults in whom the live vaccine caused the most concern, which is why the arrival of a non-live alternative has mattered so much to travel medicine.

How the two chikungunya vaccines work, and why the difference matters

Both licensed vaccines are given by injection into the muscle and both aim at the same target, the virus’s outer envelope proteins, but they get there by opposite routes.

The first, the live-attenuated vaccine, is a weakened but living version of the virus. Scientists deleted a stretch of a gene called nsP3 that the virus needs to replicate efficiently, producing a strain that can multiply just enough to alert the immune system without causing full disease. Live vaccines have a long record of producing strong, durable immunity from a single exposure; measles, yellow fever and chickenpox vaccines work this way. The trade-off is that a replicating virus can, in some people, produce a mild version of the illness it is designed to prevent, and it is generally avoided in those with weakened immune systems. This is the vaccine whose US license was suspended in 2025.

The second, the virus-like particle vaccine, contains no genetic material at all. Virus-like particles are empty protein shells assembled from the virus’s structural proteins; they look like the virus to the immune system but cannot replicate. It is paired with an aluminum-based adjuvant, an ingredient that amplifies the immune response. Hepatitis B and HPV vaccines use the same virus-like particle strategy. Because nothing in it can multiply, this type is considered suitable for people with weakened immunity, though their response may be weaker.

Neither vaccine has been shown, in a completed randomized trial, to reduce the number of chikungunya cases. Both were licensed on immunogenicity, meaning the level of neutralizing antibodies (antibodies that block the virus from entering cells) that vaccinated people produced, compared with a threshold researchers believe indicates protection. That approach, called immunobridging, is accepted by regulators for diseases where efficacy trials are impractical because outbreaks are unpredictable, but it is a weaker form of evidence than counting prevented infections.

Age indications differ. The live vaccine was licensed for adults 18 and over; the virus-like particle vaccine for people 12 and over. Both product labels and the schedule are matters for the clinician administering them.

Who is eligible for a chikungunya vaccine right now?

Eligibility has three layers: who the regulator licensed it for, who the national advisory body recommends it for, and what a clinician judges sensible for the individual. They do not always line up, and 2025 pulled them further apart.

United States. Since the August 2025 license suspension, CDC lists only the virus-like particle vaccine as available. Its recommendations, published on the CDC page in our references, follow the same logic as before. Vaccination is recommended for people 12 and older traveling to a country or territory with a current chikungunya outbreak. It may be considered for travelers to areas without an active outbreak but with evidence of transmission in the past five years, if they plan to stay six months or longer, or if they are over 65 and expect at least moderate mosquito exposure over a shorter trip, or if they have underlying conditions that raise the risk of severe disease. Laboratory workers who handle the virus are also included. CDC does not recommend it for travelers to areas without recent transmission.

Europe and the United Kingdom. Both vaccines remain authorized. For the live vaccine, European regulators advise that people 65 and older receive it only when the risk of infection is significant and after careful assessment. NHS guidance notes that vaccines are available for travelers to affected areas and directs people to a travel health consultation to decide.

WHO. The WHO fact sheet describes both vaccine types as approved in several countries but not yet in widespread use, and it emphasizes mosquito avoidance as the foundation of prevention. WHO has not issued a universal global recommendation.

Two groups need extra care. Pregnant travelers should discuss timing with their clinician; the live vaccine is generally avoided in pregnancy, and data on the non-live vaccine in pregnancy are limited. People with weakened immune systems should not receive the live vaccine and should discuss the non-live option.

Every one of these bullets ends the same way in practice: the decision belongs to the clinician assessing your trip, your age and your health.

What the evidence actually says about the chikungunya vaccine

Grading evidence means asking two questions: how strong is the study design, and how directly does it measure what patients care about? On the second question, both chikungunya vaccines currently score lower than most travelers assume.

Randomized trials, surrogate outcomes. The live-attenuated vaccine’s pivotal trial randomized roughly 4,100 US adults to vaccine or placebo. About 99 percent of vaccinated participants reached the pre-specified neutralizing antibody level at four weeks, and around 97 percent still had it at two years. The virus-like particle vaccine’s main trial randomized about 3,200 people aged 12 to 64; roughly 98 percent reached the threshold three weeks after vaccination. A separate trial in about 400 adults 65 and older found around 87 percent responded. These are well-designed, placebo-controlled studies, the highest tier for safety and immune response. But their primary outcome was an antibody level, not prevented illness, because the trials ran in places without chikungunya.

The bridge to protection. The antibody threshold was derived from studies of naturally infected people and from animal work showing that transferring antibodies at that level prevented disease. That is a reasonable chain of inference and regulators accepted it, but each link is an assumption rather than a measurement.

Real-world effectiveness. This is where the record is thin. The 2025 Indian Ocean outbreak was the first large epidemic in which a licensed vaccine was deployed at scale, and analyses are ongoing. As of late 2025 there is no completed observational study that estimates how many cases either vaccine prevents in the field.

Safety. Trial data are randomized and reassuring on common side effects. The serious reactions in older adults emerged from post-marketing surveillance, which is observational and cannot by itself prove cause, but the pattern was consistent enough for regulators to act.

So the fair summary reads: strong randomized evidence that both vaccines produce the antibody levels believed to protect; moderate evidence linking those levels to protection; no direct trial evidence of clinical efficacy yet; and an evolving safety picture that is far better characterized for the non-live vaccine in older adults.

Chikungunya vaccine side effects: what the safety data show

Side effects are where the two products diverge most sharply, and where 2025 rewrote the story.

In the live vaccine’s randomized trial, common reactions were headache, fatigue, muscle pain, joint pain, fever and nausea, mostly mild and resolving within days. A subset, around 1 to 2 percent, experienced what the label calls severe or prolonged chikungunya-like reactions: fever with joint pain lasting more than a few days, occasionally requiring medical attention. That makes intuitive sense for a vaccine built from a replicating virus. Serious adverse events were uncommon in the trial and only a couple were judged related to the vaccine.

The post-marketing picture was different. As use expanded in 2024 and 2025, regulators received reports of hospitalizations and a small number of deaths, concentrated in people in their 60s, 70s and 80s, most with underlying conditions such as heart disease or diabetes. Some reports described encephalitis-like illness or cardiac events. Surveillance data cannot prove that the vaccine caused each event, but the clustering by age and the biological plausibility of a live virus behaving more aggressively in frailer people led US advisers to add a precaution in April 2025, the FDA and CDC to recommend a pause for those 60 and over in May, and the FDA to suspend the license in August. European regulators kept the vaccine available with a case-by-case restriction for people 65 and over.

The virus-like particle vaccine’s trials reported a more familiar profile: injection-site pain in most recipients, plus fatigue, headache and muscle pain in a minority, typically lasting one to three days. Because it cannot replicate, chikungunya-like illness is not an expected reaction. Serious adverse events were rare and similar between vaccine and placebo groups. Post-marketing experience is shorter, so the confidence interval around “rare” is wider than for older vaccines.

Any injected vaccine carries a small risk of a severe allergic reaction, usually within minutes, which is why recipients are observed afterward. Fainting after injection is also reported, particularly in adolescents.

If you received the live vaccine before the suspension and feel well, there is nothing to undo; the events of concern occurred within days to weeks of vaccination. Anyone with lingering concerns should raise them with the clinician who administered it.

Does chikungunya give lifelong immunity, and how long is the vaccine good for?

Natural infection appears to be one of the few silver linings of this disease. Studies from the Indian Ocean, India and the Americas have found that people infected during one outbreak were protected during later ones, and neutralizing antibodies persist for years. CDC states that once infected, a person is likely to be protected from future infection. Unlike dengue, which has four distinct serotypes and can strike the same person up to four times, chikungunya circulates as a single serotype with several genetic lineages that the immune system treats as one target. “Lifelong” is a strong word and the follow-up data span decades rather than lifetimes, but the practical message is that reinfection is rare enough that clinicians do not usually worry about it.

The vaccine question is harder because the vaccines are new. For the live-attenuated vaccine, about 97 percent of trial participants still had antibodies above the protective threshold two years after vaccination, and a follow-up extension has reported similar persistence toward three years. For the virus-like particle vaccine, the manufacturer’s trial data show antibodies persisting at high levels through at least the first year, with longer follow-up continuing. Neither product’s label specifies a booster because no one yet knows whether or when one will be needed.

How should a traveler read this? Immunologically, a live vaccine that mimics infection has a head start on durability, and its two-year data are strong. A protein-based vaccine with adjuvant often needs more time to prove longevity, but hepatitis B and HPV vaccines built the same way have shown protection lasting well over a decade. Absence of long-term data is not evidence of short-term protection; it is simply absence of data.

The people best placed to interpret this for an individual are the clinicians and advisory committees who will update guidance as follow-up matures. Someone vaccinated in 2025 for a trip to an outbreak area should expect to be told, for now, that no booster is recommended and that the recommendation may change.

Is it worth getting the chikungunya vaccine? A framework, not a verdict

This is the question people actually type, and the honest answer is that it depends on three variables that only you and a clinician can weigh together: your destination, your personal risk, and which vaccine is on the table.

Destination. The difference between an active outbreak and “the mosquito exists there” is enormous. During the 2025 Réunion epidemic, attack rates in some communities ran into double-digit percentages of the population within months. A traveler spending three weeks in such a place faced a genuine chance of infection and weeks of joint pain. A traveler to a Caribbean island with sporadic cases faced a risk closer to that of many other travel infections for which vaccines are not routinely pushed. CDC’s tiered recommendations, outbreak versus recent transmission versus none, exist precisely to make this distinction.

Personal risk. Age over 65, chronic heart or metabolic disease, and existing joint disease all raise both the chance of severe acute illness and the chance of long-term arthritis. So does a long stay, which multiplies mosquito exposure. Pregnancy near term raises the stakes because of the newborn transmission risk, but complicates the vaccine choice.

Which vaccine. In the United States, the choice has been made for you: only the non-live vaccine is available, and its safety record in older adults is reassuring so far. Elsewhere, an older traveler considering the live vaccine should expect a frank discussion of the 2025 safety signal and, in most cases, a steer toward the alternative.

Where does evidence-based opinion land? For a healthy adult heading into an active outbreak, especially for weeks rather than days, the case for vaccination is reasonably strong: the disease is common, miserable and occasionally disabling, and the non-live vaccine’s known risks are modest. For a short trip to a low-transmission area, mosquito avoidance may be the proportionate response. In between lies most real travel, which is exactly why the guidance defers to an individual consultation.

Whatever the choice, it is not a substitute for repellent. No vaccine has yet shown field efficacy, and the same mosquitoes carry dengue and Zika, against which a chikungunya vaccine does nothing.

Mosquito protection that actually works against Aedes

Every agency that writes about chikungunya, from WHO to NHS to CDC, puts mosquito avoidance ahead of vaccination, and not as a platitude. It is the only measure that also covers dengue and Zika, and it worked to end outbreaks in Italy and China without a single vaccine dose.

The first thing to unlearn is the malaria mindset. Aedes mosquitoes bite in daylight, most intensely in the two hours after sunrise and the few hours before sunset, and they favor ankles and lower legs. They live inside and around homes, breeding in a bottle cap of clean water: plant saucers, gutters, discarded tires, uncovered water tanks. A bed net protects a sleeping infant but does nothing for an adult at a lunchtime café.

Repellent is the workhorse. CDC and NHS point to products registered with the US Environmental Protection Agency containing DEET, picaridin, IR3535 or oil of lemon eucalyptus (PMD), applied to exposed skin and reapplied according to the label, over rather than under sunscreen. Concentration governs duration, not strength, so a higher percentage lasts longer rather than repelling better. Children over two months can use most of these; oil of lemon eucalyptus is not recommended under three years.

Clothing adds a layer. Long, loose sleeves and trousers in light colors reduce bites, and permethrin-treated fabric, available pre-treated or as a spray for clothes and gear (never skin), adds several washes’ worth of protection.

Where you sleep matters. Air conditioning and intact window screens sharply cut indoor biting; where neither exists, an insecticide-treated net still helps against dawn bites.

Finally, if you do fall ill, you become part of the chain. A viremic traveler bitten at home can seed local transmission where tiger mosquitoes live, which now includes much of the southern and eastern United States and Mediterranean Europe. WHO advises anyone with suspected chikungunya to avoid mosquito bites for the first week of illness. It is one of the few times in medicine when protecting yourself and protecting your neighbors are literally the same action.

Common myths about chikungunya and the vaccine, corrected

Outbreaks generate confident claims at roughly the same speed as mosquitoes. A few of the most persistent deserve a direct answer.

“Chikungunya is just mild dengue.” They are different virus families with different dangers. Dengue kills through bleeding and shock; chikungunya’s burden is joint pain that can persist for months. Treating them as interchangeable leads people to underestimate dengue’s warning signs and overestimate chikungunya’s lethality.

“The vaccine was banned because it kills people.” The US suspension of the live vaccine followed reports of serious reactions and a small number of deaths, mostly in older adults with underlying conditions. It remains authorized in Europe with age-based cautions, and the non-live vaccine was not involved at all. Regulators acted on a risk signal in a specific group, which is what surveillance systems are designed to do.

“Once you have the vaccine you can skip repellent.” Neither vaccine has yet demonstrated efficacy against disease in the field, and neither protects against dengue or Zika carried by the same mosquitoes.

“Chikungunya causes birth defects like Zika.” Infection around the time of delivery can pass the virus to the newborn, which is serious, but there is no established link between chikungunya and congenital malformations.

“You can catch it from another person.” Transmission requires a mosquito, with the exception of mother-to-child transmission at birth and rare cases through blood products. Sharing a room with a patient is not a risk.

“Papaya leaf, neem or vitamin megadoses cure it.” No randomized trial supports any herbal or supplement treatment for chikungunya. Supportive care is the only evidence-based approach, and some supplements can interact with prescribed medicines.

“Cold countries are safe.” Aedes albopictus survives winters as far north as Paris and New Jersey. Local transmission in France in 2025 shows that “tropical disease” is a shrinking label.

“If you had it once, you can get it again next year.” Natural immunity appears long-lasting; documented reinfections are rare.

When to see a doctor

Most people with chikungunya recover at home with rest and fluids. Some situations should not wait, whether the concern is the infection itself, a possible dengue misdiagnosis, or a reaction to a vaccine.

Seek urgent care during a fever illness after travel or mosquito exposure if you notice:

• Severe or persistent abdominal pain, repeated vomiting, or inability to keep fluids down
• Bleeding from the gums or nose, blood in vomit or stool, or unusual bruising
• Rapid or difficult breathing, cold clammy skin, or feeling faint on standing
• Confusion, drowsiness that is hard to rouse, a stiff neck, or a seizure
• Chest pain or an irregular heartbeat
• Fever in a newborn or infant under three months, or in a baby whose mother was ill around delivery
• Fever in late pregnancy

Several of these are dengue warning signs rather than chikungunya features, which is the point: until a clinician has ruled dengue out, they should be treated as if they were.

Make a routine appointment if: joint pain is still limiting daily activities after four to six weeks; joints become newly hot, red or swollen weeks or months after the illness; or you have an existing heart, kidney or metabolic condition and have developed a febrile illness after travel, even without red flags.

After a chikungunya vaccine, seek urgent care for: swelling of the face or throat, hives spreading over the body, wheezing or difficulty breathing within hours of the injection; a high fever with severe joint pain lasting more than a few days, especially in someone over 60 who received the live vaccine; confusion, severe headache with a stiff neck, chest pain, or fainting that is not immediate and brief. Mild soreness, tiredness and headache for a day or two are expected and do not need assessment.

Before travel, anyone weighing vaccination, particularly those over 65, pregnant, immunocompromised or living with chronic illness, should have that conversation with the clinician who can see their full history. This article can explain the evidence; only they can apply it.

Frequently asked questions

Is it worth getting the chikungunya vaccine?

For most people the answer hinges on whether the destination has an active outbreak. CDC recommends vaccination for travelers 12 and older to areas with a current outbreak and says it may be considered for longer stays, older travelers or those with health conditions visiting areas with recent transmission. For short trips to low-transmission areas, mosquito avoidance may be proportionate. The clinician assessing your itinerary, age and health should make the call with you.

How long is a chikungunya vaccine good for?

Nobody knows the full answer yet because the vaccines are new. Trial follow-up shows about 97 percent of people who received the live-attenuated vaccine still had protective-level antibodies at two years, and the virus-like particle vaccine has shown persistent antibodies through at least a year with follow-up continuing. No booster is currently recommended for either. Guidance will be updated as longer data mature, so ask at the time of vaccination.

How much does a chikungunya vaccine cost?

This article does not report prices, because costs and insurance coverage vary widely by country, insurer and vaccine and change often. Travel vaccines in the United States are frequently not covered in the same way routine childhood vaccines are, though some plans do include them. The clinician who assesses your travel risk, or your insurer, can give you an accurate figure for your situation before you decide.

Does chikungunya give lifelong immunity?

Very probably long-lasting immunity, and possibly lifelong, though follow-up data span decades rather than whole lifetimes. Because chikungunya circulates as a single serotype, antibodies made after one infection recognize later strains, and documented reinfections are rare. CDC states that once infected, a person is likely to be protected from future infections. This differs sharply from dengue, where four serotypes mean a person can be infected repeatedly.

What are the chikungunya vaccine side effects?

The non-live virus-like particle vaccine most often causes injection-site pain, tiredness, headache and muscle aches for one to three days. The live-attenuated vaccine caused similar reactions plus, in about 1 to 2 percent of trial participants, a chikungunya-like illness with fever and joint pain; post-marketing reports of hospitalizations and a few deaths in older adults led to its US license being suspended in 2025. Severe allergic reactions are rare with any vaccine.

How long does chikungunya last?

The fever usually settles within two to three days and most people feel largely recovered in a week to ten days. Joint pain is the exception: a substantial minority still have pain or stiffness at three months, and a smaller group at a year or more, with older adults and people with prior joint problems most affected. Most improve steadily over the first year, but worsening or newly swollen joints warrant medical review.

Chikungunya vs dengue symptoms: how can I tell which one I have?

You usually cannot tell reliably in the first days, and neither can a clinician without a test. Both cause sudden high fever, headache, aches and rash. Clues favoring chikungunya are severe symmetric joint pain in the hands, wrists and ankles; clues favoring dengue are deep muscle and bone pain, pain behind the eyes and a falling platelet count. Because dengue can turn dangerous, get tested and let a clinician guide pain relief.

Where is the chikungunya outbreak in 2025 happening?

The largest 2025 outbreaks were on La Réunion and neighboring Indian Ocean islands, in Guangdong province in southern China, and across parts of South Asia and South America, notably Brazil and Bolivia. France recorded its highest-ever number of locally acquired cases and Italy reported clusters. The United States saw only travel-related cases; no local transmission has been reported on the mainland since 2015. CDC’s travel notices track current outbreaks.

Is the chikungunya vaccine still available in the United States?

One is. The FDA suspended the license of the live-attenuated vaccine on 22 August 2025 following reports of serious adverse events in older adults, so it is no longer available in the United States. The virus-like particle vaccine, approved in February 2025 for people 12 and older, remains available and is the vaccine CDC’s current travel recommendations refer to. Outside the US, both vaccines remain authorized in several countries with age-specific cautions on the live one.

Can pregnant people, children or immunocompromised people get the chikungunya vaccine?

It depends on the vaccine and the person. The virus-like particle vaccine is licensed from age 12 and, because it contains no live virus, can be discussed for people with weakened immune systems, though their response may be weaker. The live vaccine is not recommended for immunocompromised people and is generally avoided in pregnancy. Data on any chikungunya vaccine in pregnancy are limited, so the decision rests with the treating clinician after weighing travel risk.

References

• CDC: About Chikungunya
• WHO: Chikungunya fact sheet
• WHO: Dengue and severe dengue fact sheet
• MedlinePlus: Chikungunya

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.