RSV Vaccine: Who Should Get Vaccinated & Side Effects

What Is RSV and Why Is Vaccination Important?

RSV (Respiratory Syncytial Virus) is a common respiratory virus that causes cold-like symptoms in most people but can lead to severe pneumonia and bronchiolitis in older adults and young children. Vaccination is the most effective way to prevent serious RSV illness in high-risk populations.

Respiratory Syncytial Virus, commonly known as RSV, is one of the most widespread respiratory viruses affecting humans globally. For most healthy adults and older children, RSV infection resembles a common cold with symptoms like runny nose, coughing, and mild fever. However, the virus poses a significantly greater threat to certain vulnerable populations, making vaccination a critical public health intervention.

The virus primarily spreads during the colder months, typically from late fall through early spring in temperate climates. During this period, RSV circulates widely in communities, easily transmitting from person to person through respiratory droplets when an infected individual coughs, sneezes, or even breathes. The virus can also survive on surfaces for several hours, meaning transmission can occur when someone touches a contaminated surface and then touches their face, particularly the nose, mouth, or eyes.

What makes RSV particularly concerning from a public health perspective is its disproportionate impact on older adults and very young children. In adults over 65 years of age, RSV infection can rapidly progress from mild upper respiratory symptoms to severe lower respiratory tract disease, including pneumonia and acute respiratory distress. Studies have shown that RSV causes approximately 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths annually among adults 65 and older in the United States alone. Globally, RSV is responsible for significant morbidity and mortality in aging populations.

For infants, especially those under 6 months of age, RSV represents the leading cause of bronchiolitis and pneumonia. Young infants lack the developed immune systems necessary to fight off the infection effectively, and their small airways are particularly vulnerable to the inflammation RSV causes. Before the availability of preventive interventions, RSV resulted in hundreds of thousands of infant hospitalizations worldwide each year.

How RSV Spreads

Understanding RSV transmission is essential for both prevention and appreciating why vaccination is so valuable. The virus spreads through several mechanisms that make it highly contagious in community settings.

Respiratory droplet transmission occurs when an infected person coughs, sneezes, or exhales, releasing virus-containing particles into the air. People nearby can inhale these droplets directly or have them land on their mucous membranes (eyes, nose, or mouth). This mode of transmission is most efficient in close-contact situations, which explains why RSV spreads readily within households, healthcare facilities, and congregate care settings.

Surface contamination, also called fomite transmission, represents another important pathway. RSV can survive on hard surfaces like doorknobs, tables, and handrails for several hours under typical indoor conditions. When a susceptible person touches these contaminated surfaces and then touches their face, they can inadvertently transfer the virus to their respiratory tract.

Indoor environments significantly increase transmission risk. Enclosed spaces with limited ventilation allow respiratory droplets to accumulate and persist longer, increasing exposure opportunities. This partially explains the seasonal pattern of RSV, as people spend more time indoors during colder months when heating systems create dry air that may help the virus survive longer.

Reducing RSV Infection Risk

While vaccination represents the most effective protection against severe RSV disease, several behavioral measures can help reduce infection risk, particularly for individuals who cannot receive the vaccine or are awaiting vaccination.

• Hand hygiene: Frequent handwashing with soap and water for at least 20 seconds, or using alcohol-based hand sanitizers when soap is unavailable, effectively removes RSV from hands and reduces transmission risk
• Avoid face touching: Consciously avoiding touching the eyes, nose, and mouth prevents transferring virus from contaminated hands to respiratory mucosa
• Limit exposure to sick individuals: When possible, avoiding close contact with people showing respiratory illness symptoms reduces direct droplet exposure
• Surface cleaning: Regular disinfection of frequently touched surfaces in homes and workplaces removes viable virus from the environment
• Mask wearing: In high-risk situations, particularly during peak RSV season, wearing a well-fitted mask provides additional protection against respiratory droplet transmission

Who Should Get the RSV Vaccine?

RSV vaccination is recommended for adults 75 years and older, adults 60-74 with certain chronic conditions (heart disease, lung disease, diabetes, obesity, weakened immune system), and pregnant women between weeks 24-36 of pregnancy. Newborns can receive RSV antibodies for protection during their first months of life.

Health authorities worldwide, including the World Health Organization, Centers for Disease Control and Prevention, and European Centre for Disease Prevention and Control, have established clear recommendations for RSV vaccination. These recommendations are based on extensive clinical trial data demonstrating vaccine safety and efficacy, along with epidemiological evidence identifying populations at greatest risk for severe RSV outcomes.

The primary target population for RSV vaccination includes older adults, where age-related immune system changes (immunosenescence) increase vulnerability to severe infection. The advisory committees have identified specific age thresholds and risk factors that should prompt vaccination consideration.

Adults 75 Years and Older

All adults aged 75 and older are recommended to receive RSV vaccination regardless of underlying health conditions. This universal recommendation for the oldest age group reflects the significantly elevated risk of hospitalization, intensive care admission, and death from RSV infection in this population. Even in the absence of specific chronic diseases, the aging immune system's diminished capacity to respond to RSV infection justifies vaccination.

Clinical trials have demonstrated that RSV vaccines maintain strong efficacy in this age group, with protection against hospitalization remaining robust even among those in their 80s and 90s. The benefit-risk assessment strongly favors vaccination, as the consequences of RSV infection in this age group frequently include prolonged hospitalization, functional decline, and mortality.

Adults 60-74 with Chronic Conditions

For adults between 60 and 74 years of age, vaccination recommendations are based on the presence of underlying health conditions that increase RSV severity risk. These conditions include:

Additionally, individuals with liver failure, kidney failure, multiple functional limitations requiring daily assistance, or neuromuscular diseases affecting respiratory function are recommended for vaccination. The common thread among these conditions is either direct respiratory system involvement or immune system impairment that increases vulnerability to severe RSV outcomes.

Healthcare providers may also recommend RSV vaccination for adults 60-74 with other conditions not explicitly listed but that the treating physician judges to increase RSV risk based on the individual patient's overall health status and clinical circumstances.

Pregnant Women

RSV vaccination during pregnancy represents a breakthrough in protecting the most vulnerable population: newborn infants. When pregnant women receive RSV vaccine between gestational weeks 24 and 36, their immune systems produce antibodies against RSV that cross the placenta and provide passive immunity to the developing fetus.

After birth, these maternally-transferred antibodies continue to circulate in the infant's bloodstream, providing protection against severe RSV infection during the critical first months of life. Clinical trials have demonstrated that maternal RSV vaccination reduces severe RSV lower respiratory tract infection in infants by approximately 70-80% during the first 90 days of life, with continued protection extending through 6 months of age.

The timing window of 24-36 weeks gestation is carefully chosen to optimize antibody transfer while allowing sufficient time between vaccination and delivery. At least two weeks should ideally pass between vaccination and birth to ensure adequate antibody transfer to the baby. Pregnant women considering RSV vaccination should discuss timing with their healthcare provider or prenatal care team.

Newborn RSV Antibody Protection

For infants born to mothers who did not receive RSV vaccination during pregnancy, another protective option exists: monoclonal antibody administration shortly after birth. These antibodies provide similar protection to that conferred by maternal vaccination, protecting infants through their first RSV season.

In many countries, newborns are now routinely offered RSV antibodies as part of their early postnatal care. This intervention has dramatically reduced RSV hospitalizations among young infants in populations where it has been implemented.

Where and When Can You Get Vaccinated?

RSV vaccination is available at many healthcare facilities, including clinics, pharmacies, and vaccination centers. The optimal timing is before RSV season begins, typically in early fall for Northern Hemisphere regions. Vaccine availability and cost coverage vary by country and insurance status.

Access to RSV vaccination has expanded significantly since the vaccines received regulatory approval in 2023. Understanding where to obtain vaccination and the optimal timing helps ensure individuals receive protection when it matters most.

RSV vaccines are administered at various healthcare settings, though availability may vary depending on your location and healthcare system. Common vaccination sites include primary care physician offices, hospital-based clinics, specialized vaccination centers, and in many countries, pharmacies with vaccination services. Some employers and community organizations also sponsor vaccination clinics, particularly during fall immunization campaigns.

Optimal Vaccination Timing

RSV follows a predictable seasonal pattern, with transmission typically beginning in late fall, peaking in winter, and subsiding by early spring. This seasonality makes timing an important consideration for vaccination.

For maximum protection during peak RSV season, vaccination in early fall (September through October in the Northern Hemisphere) is generally recommended. This timing allows the immune system approximately two weeks to develop protective antibody levels before RSV transmission intensifies.

However, vaccination later in the season still provides benefit, particularly for individuals who missed the optimal window. Protection begins within two weeks of vaccination, so even mid-winter vaccination offers meaningful protection for the remainder of the RSV season.

Vaccine Cost and Coverage

RSV vaccine cost and insurance coverage vary considerably by country and healthcare system. In some countries, RSV vaccination is provided free of charge for recommended groups through national immunization programs. In others, individuals may need to pay out-of-pocket or through private insurance.

Many insurance plans cover RSV vaccination for recommended populations, though coverage details vary. Before scheduling vaccination, checking with your insurance provider or healthcare facility about coverage and any out-of-pocket costs is advisable.

How Does the RSV Vaccination Process Work?

RSV vaccination is a simple process involving a single injection into the upper arm muscle. The procedure takes only minutes, and you may be asked to remain briefly for observation. No special preparation is required, though you should inform healthcare providers about any previous vaccine reactions or allergies.

The RSV vaccination process is straightforward and similar to other routine adult vaccinations like flu shots or COVID-19 vaccines. Understanding what to expect can help reduce any anxiety about the procedure.

Before Vaccination

Before receiving RSV vaccine, a healthcare provider will typically review your health history and confirm that vaccination is appropriate. Important information to share includes any previous allergic reactions to vaccines, known allergies to vaccine components, current illness with fever, and any immunocompromising conditions or medications.

No special preparation is required for RSV vaccination. You can eat and drink normally before the appointment, and no fasting is necessary. Wearing clothing that allows easy access to your upper arm (where the injection is typically given) can make the process smoother.

The Vaccination Procedure

RSV vaccine is administered as an intramuscular injection, typically into the deltoid muscle of the upper arm. The injection itself takes only seconds and involves a standard vaccine needle. Most people describe the sensation as a brief pinch or pressure.

After the injection, the healthcare provider may apply a small bandage to the injection site. The entire procedure, from preparation to completion, typically takes less than 5 minutes.

Post-Vaccination Observation

Many vaccination sites ask patients to remain for 15 minutes following vaccination. This brief observation period allows healthcare providers to monitor for rare immediate allergic reactions (anaphylaxis), which typically occur within minutes of vaccination if they occur at all.

Serious immediate reactions to RSV vaccines are extremely rare, but having trained personnel and emergency medications available during the observation period provides an additional safety margin.

What Are the Side Effects of RSV Vaccine?

Common RSV vaccine side effects include pain, tenderness, and swelling at the injection site, along with mild systemic symptoms like fatigue, headache, and low-grade fever. These effects typically appear within 24 hours and resolve within 1-2 days. Serious side effects are rare.

Like all vaccines, RSV vaccines can cause side effects, though most are mild and temporary. Understanding what to expect helps distinguish normal vaccine responses from symptoms that warrant medical attention.

Common Side Effects

The most frequently reported side effects following RSV vaccination are injection site reactions. These local effects occur because the immune system recognizes the vaccine components and begins mounting a protective response. Common injection site symptoms include:

• Pain or tenderness: The most common side effect, reported by approximately 50-70% of vaccine recipients, ranging from mild discomfort to moderate soreness
• Swelling: Mild swelling around the injection site, typically resolving within 2-3 days
• Redness: Localized erythema (redness) at the injection site, generally mild and temporary
• Warmth: The injection site may feel warm to touch as part of the local inflammatory response

Systemic side effects, meaning symptoms affecting the whole body, also occur but are generally less common than injection site reactions. These may include:

• Fatigue: Feeling tired or having less energy than usual for 1-2 days
• Headache: Mild to moderate headache, typically responsive to standard pain relievers
• Muscle aches: General muscle soreness or body aches
• Low-grade fever: Temperature elevation, usually below 101°F (38.3°C)
• Gastrointestinal symptoms: Mild nausea, diarrhea, or stomach discomfort in some recipients

These side effects typically appear within the first 24 hours after vaccination and resolve within 1-2 days without requiring medical treatment. Over-the-counter pain relievers like acetaminophen or ibuprofen can help manage discomfort if needed.

Managing Side Effects

Several simple measures can help manage common vaccine side effects and improve comfort during the brief period when they occur:

Rare and Serious Side Effects

Serious side effects from RSV vaccines are uncommon. As with any vaccine, severe allergic reactions (anaphylaxis) can occur but are extremely rare, estimated at approximately 1-2 cases per million doses administered. Signs of severe allergic reaction include difficulty breathing, facial swelling, widespread hives, rapid heartbeat, and dizziness, typically occurring within minutes of vaccination.

Clinical trials have monitored for other potential serious adverse events. Some surveillance has detected a possible small increased risk of Guillain-Barré syndrome (a rare neurological condition) following RSV vaccination in older adults, though the absolute risk, if real, appears very small. Ongoing safety monitoring continues to evaluate this potential signal.

The benefits of RSV vaccination in preventing severe respiratory illness, hospitalization, and death substantially outweigh the small risks of serious adverse events for individuals in recommended vaccination groups.

When Should You Not Get the RSV Vaccine?

RSV vaccination should be postponed if you have fever or acute illness. It should not be given to individuals with history of severe allergic reaction to a previous RSV vaccine dose or known allergy to vaccine components. Always discuss your medical history with a healthcare provider before vaccination.

While RSV vaccines are safe for most people in recommended groups, certain circumstances warrant postponement or contraindicate vaccination. Understanding these situations helps ensure safe vaccination practices.

Temporary Postponement

Vaccination should be temporarily delayed when:

• Acute febrile illness: If you have a fever or feel acutely unwell, waiting until symptoms resolve allows your immune system to respond optimally to the vaccine and prevents confusion between vaccine side effects and illness symptoms
• Moderate to severe acute illness: Any significant acute illness, even without fever, is generally a reason to postpone vaccination until recovery

Minor illnesses without fever, such as mild colds, are generally not reasons to delay vaccination. Healthcare providers can help determine whether postponement is appropriate based on your specific situation.

Contraindications

Certain circumstances represent absolute contraindications to RSV vaccination:

If you have concerns about vaccine allergies, allergists can perform testing to determine whether specific vaccine components pose a risk. In some cases, vaccination may still be possible under medical supervision with appropriate precautions.

How Effective Is the RSV Vaccine?

RSV vaccines demonstrate approximately 83% efficacy against severe RSV disease in older adults during the first season after vaccination. For pregnant women, maternal vaccination provides approximately 70-80% protection against severe infant RSV illness for the first 90 days after birth, with continued benefit through 6 months.

Understanding vaccine effectiveness helps set appropriate expectations and appreciate the significant protection RSV vaccination provides. Clinical trials involving tens of thousands of participants have established robust efficacy data.

Efficacy in Older Adults

Phase 3 clinical trials of RSV vaccines in adults 60 years and older demonstrated impressive efficacy against severe RSV lower respiratory tract disease. The vaccines showed approximately 83% efficacy in preventing RSV-associated lower respiratory tract disease with at least two signs or symptoms during the first RSV season following vaccination.

Protection against hospitalization was similarly robust, with vaccines preventing a substantial proportion of RSV-related hospital admissions. This is particularly important given that hospitalized RSV patients often require extended stays, intensive care, and have elevated mortality risk.

Efficacy data from the second RSV season after vaccination showed some waning of protection, though vaccines continued to provide meaningful benefit. Research is ongoing to determine optimal timing for booster doses, and recommendations will evolve as more long-term data becomes available.

Efficacy in Pregnant Women (Protecting Infants)

For maternal RSV vaccination, efficacy is measured by protection conferred to infants after birth. Clinical trials demonstrated that maternal vaccination between weeks 24-36 of pregnancy provided approximately 70-80% protection against severe RSV lower respiratory tract infection in infants during their first 90 days of life.

Protection remained significant, though somewhat reduced, through 6 months of age. This time frame coincides with the period of highest RSV vulnerability for infants, before their own immune systems have matured sufficiently to handle RSV infection.

Real-World Effectiveness

Post-marketing studies examining vaccine performance in routine clinical practice have generally confirmed the efficacy observed in clinical trials. These real-world data are reassuring because they reflect vaccine performance in diverse populations under typical conditions rather than the carefully controlled environment of clinical trials.

How Do Vaccines Work to Protect Against Disease?

Vaccines work by training the immune system to recognize and fight specific pathogens without causing disease. RSV vaccines contain viral proteins that stimulate antibody production, preparing the body to rapidly neutralize the virus upon actual exposure. This immune memory provides protection against severe infection.

Understanding how vaccines work helps appreciate why vaccination is such an effective public health intervention. The principles underlying RSV vaccination apply broadly to other vaccines as well.

The Immune System's Learning Process

When a pathogen like RSV enters the body, the immune system must first recognize it as foreign before mounting a defensive response. This recognition process takes time during a first-time infection, during which the virus can replicate and cause disease symptoms.

Vaccines accelerate this process by presenting harmless components of the pathogen to the immune system in advance. For RSV vaccines, the key component is the viral F (fusion) protein, which RSV uses to enter and infect cells. By exposing the immune system to this protein in a vaccine, the body develops the ability to recognize and respond to RSV before natural infection occurs.

Antibody Production and Memory

Following vaccination, specialized immune cells called B cells produce antibodies specifically targeting the vaccine components. These antibodies can neutralize RSV by binding to the virus and preventing it from infecting cells. Some antibodies also flag infected cells for destruction by other immune cells.

Importantly, vaccination also creates memory B cells and memory T cells that persist long after the initial vaccine response. These memory cells allow the immune system to respond rapidly and robustly if exposed to the actual virus, often preventing infection from taking hold or limiting its severity.

Why Vaccination Differs from Natural Infection

While natural RSV infection also stimulates immunity, vaccination offers significant advantages. The vaccine provides immune stimulation without the risks of disease, which for RSV can include pneumonia, respiratory failure, and death in vulnerable populations. Vaccination also allows controlled, optimal stimulation of the immune system under conditions designed to maximize protective response.

For pregnant women, vaccination provides the additional benefit of transferring protective antibodies to the fetus - something that cannot occur with natural infection timing.