Pharmacologic class (EPC) · 3 drug pages

Respiratory syncytial virus Anti-F protein monoclonal antibody: adverse event reports filed with FDA

16,458 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

16,458
reports across the class: 0.1% of all reports; 874
reports, 12 months to June 2026: 1,024 in the 12 months before; 78.5%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

Respiratory syncytial virus Anti-F protein monoclonal antibody is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 16,458 adverse event reports received by FDA, 0.1% of the database, from January 2004 to June 2026.

874 reports arrived in the 12 months to June 2026, down 15% from 1,024 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 78.5% of the class's reports are marked serious, 11.5% record death among the outcomes and 59.6% record hospitalisation, as reported.

Across the class the reactions recorded most often are respiratory syncytial virus infection (13.8%), pyrexia (9.2%) and bronchiolitis (8.5%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
SynagisPalivizumab	brand	14,497	82	79.7%	Respiratory syncytial virus infection
BeyfortusNirsevimab	brand	1,410	680	58.9%	Drug ineffective
Palivizumab	generic	551	112	99.1%	Bronchiolitis

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Respiratory syncytial virus infection13.8%2,275
Pyrexiafever9.2%1,513
Bronchiolitis8.5%1,404
Coughcough6.7%1,106
Deaththe patient died; cause not stated by this term6.5%1,072
Pneumonialung infection5.7%945
Dyspnoeashortness of breath5%816
Vomitingbeing sick4%662
Nasopharyngitisa cold3.9%645
Influenzaflu3.1%508
Respiratory syncytial virus bronchiolitis3%486
Drug ineffectivethe medicine did not work as expected2.7%447
Bronchitischest infection2.6%431
Diarrhoealoose or frequent stools2.4%399
Product dose omission issuea dose was missed2.3%383
Off label useused for a purpose or in a way not on the label2.3%372
Covid-19COVID-19 infection2.2%368
Nasal congestiona blocked nose2.2%364
Rhinorrhoeaa runny nose2.2%360
Illness2.2%358
Oxygen saturation decreased2.1%353
Respiratory syncytial virus test positive2.1%349
Malaisegeneral feeling of being unwell2.1%348
Wheezingwheezing2.1%340
Weight decreasedweight loss2%337

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death11.5%1,895

Life-threatening2.6%424

Hospitalisation (initial or prolonged)59.6%9,802

Disability0.3%55

Congenital anomaly0.2%40

Other serious23%3,778

Not serious21.5%3,532

Patient age

Under 255.3%9,100

2 to 111.3%219

12 to 170%7

18 to 440.2%27

45 to 640.1%18

65 to 740.1%13

75 and over0%8

Age not given42.9%7,066

Who reported

Physician21.2%3,494

Pharmacist2.1%342

Other health professional34%5,601

Lawyer0%3

Consumer or non-health professional32.7%5,376

Not given10%1,642

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Respiratory syncytial virus Anti-F protein monoclonal antibody reports

Which drugs are in the Respiratory syncytial virus Anti-F protein monoclonal antibody class on this site?

Synagis, Beyfortus and Palivizumab. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

16,458 reports through June 2026, 874 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

respiratory syncytial virus infection (13.8%), pyrexia (9.2%), bronchiolitis (8.5%), cough (6.7%) and death (6.5%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.