VACCINE LABELS

Examining the vaccine labels is the starting point when learning about the benefits and risks of a vaccine. Vaccine label is an official record of the vaccine's characteristics, including indications, contraindications and possible side effects. It is regularly updated based on information from newly conducted clinical trials and from postmarketing use (data from VAERS and specialized registries). Some vaccines are part of standard childhood immunization schedule (e.g., diphtheria, tetanus and pertussis), others are only administered before travel to affected areas (cholera, Japanese encephalitis). For some diseases (e.g., meningitis caused by Neisseria meningitidis)  multiple different vaccine variants exist. This guide provides a brief summary of the disease the vaccine protects against with links to more comprehensive information, and a table with vaccine name, application number, labeler, and a link to the product label.

ADENOVIRUS

Adenoviruses commonly cause respiratory illnesses ranging from the common cold to pneumonia, croup, and bronchitis, but also gastroenteritis, conjunctivitis, cystitis, or neurological disease. Adenoviruses have been a common cause of acute respiratory illness in military recruits. As non-enveloped viruses, adenoviruses are relatively resistant to common disinfectants. There are more than 50 types of immunologically distinct adenoviruses. People with weakened immune systems are at high risk of developing a severe disease caused by adenovirus infection (CDC, Health.mil). The vaccine is mandatory for all enlisted military recruits (Army Regulation 40-562). 

ANTHRAX

Anthrax is a serious infectious disease caused by the bacteria Bacillus anthracis. People or animals can contract anthrax from contact with infected animals or contaminated animal products. Bacillus anthracis forms spores than can survive in the environment, especially soil or animal products (e.g., rawhide) for decades. The most common route of exposure is via skin scrapes when working with infected animals resulting in cutaneous anthrax. Gastrointestinal infection occurs following eating raw or undercooked infected or contaminated meat. The most dangerous form of anthrax follows after inhalation of aerosolized anthrax spores, typically during industrial processing of infected animal products (e.g., rawhide, wool). In the United States, anthrax is very rare. Vaccination of livestock is recommended in areas with historical occurrences of anthrax. Moreover, all food animals are examined before slaughter (Mayo Clinic, Guide to Understanding Anthrax,   ACIP). Anthrax spores had been mass-produced as a bioweapon by the Soviet Union (STAT News). In 2001, anthrax was also used as a bioweapon when letters laced with anthrax were mailed to several news media offices and Democratic Senators Tom Daschle and Patrick Leahy, killing five and sickening 17 (Amerithrax investigation). Anthrax vaccine BioThrax is given to adults at increased risk of exposure in five doses, with a booster dose each year. It is also used as post-exposure prophylaxis in combination with antibiotics. 

BACILLE CALMETTE-GUERIN (BCG) - TUBERCULOSIS

Tuberculosis (TB) is a potentially serious infectious disease caused by the bacteria Mycobacterium tuberculosis. The bacteria spread from person to person through tiny droplets released during coughs and sneezes. Tuberculosis is rare in developed countries, mainly occurring as co-infection in people with HIV/AIDS. Tuberculosis is treatable with a combination of antibiotics, typically isoniazid and rifampicin, pyrazinamide, and ethambutol. The treatment typically lasts six months or more. Many tuberculosis strains are antibiotic-resistant, and other regimens must be used (Merck Manual). Bacille Calmette-Guerin (BCG) is a vaccine for tuberculosis disease. It is used in many countries with a higher prevalence of tuberculosis. In the United States, the BCG vaccine is only recommended for high-risk persons. It is administered to newborns at about four weeks of age (CDC, NHS, ACIP). 

CHOLERA

Cholera is an acute illness of the small bowel caused by a toxin produced by the bacteria Vibrio cholerae. The toxin causes watery diarrhea, leading to dehydration, renal failure, and circulatory collapse. People typically contract the disease through contaminated water or shellfish. Treatment consists of vigorous rehydration and electrolyte replacement antibiotic treatment (doxycycline) (Merck Manual). Vaccination against cholera is required when traveling to many African and Asian countries (CDC, ACIP). 

COVID-19

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. Most people experience mild to moderate respiratory illness and recover spontaneously. Older people and those with underlying medical conditions such as obesity, cardiovascular disease, diabetes, chronic respiratory disease, or immunocompromised are more likely to develop severe illness. Transmission is mainly via droplets released during coughing and sneezing (WHO, CDC). Extraordinary measures taken during the pandemic include the rapid introduction of vaccines based on novel mRNA and virus-vector technologies. A comprehensive National COVID19 Preparedness Plan exists in the U.S. (WH Covid Plan). Current vaccination recommendations are published at the CDC website (ACIP).

DENGUE (BREAKBONE FEVER, DENGUE HAEMORHAGIC FEVER)

Dengue is a hemorrhagic fever caused by a flavivirus that is transmitted by mosquitoes. Dengue fever manifests as an abrupt onset of high fever, headache, muscle, joint ache, and swollen lymph nodes. After an apparent recovery, a rash and second fever appear, sometimes with respiratory symptoms. Dengue can also cause potentially fatal hemorrhagic fever. Treatment is symptomatic; no specific treatment exists. Vaccination against Dengue is required when traveling to many countries in Central and South America, Africa, and South-East Asia (CDC, Merck Manual, Haz-Map). Current vaccination recommendations are available at CDC website (ACIP).

DIPTHTHERIA, TETANUS, PERTUSSIS

DIPHTHERIA. Diphtheria is an infection caused by toxin-producing bacteria Corynebacterium diphtheriae. The disease manifests as nonspecific skin infection or pseudomembranous pharyngitis. Later, secondary myocardial and nervous tissue damage develops due to the exotoxin. Treatment is with antitoxin and antibiotics penicillin or erythromycin (Merck Manual).

TETANUS (lockjaw). Tetanus is acute poisoning from a neurotoxin produced by the bacteria Clostridium tetani. The bacteria form spores that remain viable in soil and animal feces for years. Tetanus is rare due to widespread vaccination in the developed world, including the U.S. Symptoms are intermittent tonic spasms of skeletal muscles; characteristically, the masseters; hence the name lockjaw. Treatment is with human tetanus immune globulin and intensive support (Merck Manual.

PERTUSSIS (whooping cough). Pertussis is a highly infectious disease caused by the bacteria Bordetella pertussis. Transmission is mainly via droplets of respiratory secretions during the early phases of the disease. About 80% of close contacts get infected. Symptoms include paroxysmal or spasmodic coughing accompanied by a high-pitched whoop during inspiration. Treatment is with macrolide antibiotics. Occasional outbreaks occur due to waning immunity in adolescents and adults and unvaccinated children, but also increasing virulence of the pathogen (Merck Manual). Diphtheria, tetanus, and pertussis vaccines are typically administered as part of the standard childhood vaccination schedule (ACIP). 

DIPTHTHERIA, TETANUS, PERTUSSIS and COMBINATIONS

Diphtheria, tetanus, and pertussis vaccine is sometimes bundled with additional vaccines, namely inactivated poliovirus, Haemophilus B, and Hepatitis B (ACIP). 

HAEMOPHILUS INFLUENZAE TYPE B (Hib)

Haemophilus influenzae type b (Hib) is a bacterial infection that can cause serious disease, particularly in young children and adults with underlying severe illnesses. Hib infection can manifest as meningitis, sepsis, pneumonia, pericarditis, epiglottitis, septic arthritis, cellulitis, or osteomyelitis. Even with intravenous antibiotics, Hib meningitis infection often leaves children with hearing problems, learning disabilities, and seizures. Hib infections are now rare due to widespread childhood vaccination. Hib spreads via droplets released during coughs and sneezes. Many healthy people carry the bacteria in their nose and throat without any symptoms (NHS, CDC). Current vaccination recommendations are available at CDC website (ACIP).

HEPATITIS A

Hepatitis A is caused by a single-stranded RNA picornavirus. Hepatitis A spreads primarily by fecal-oral contact due to poor hygiene. Typical symptoms in older children and adults include anorexia, malaise, and jaundice. Young children may be asymptomatic. Hepatitis A typically resolves with supportive treatment. The disease does not progress into chronic hepatitis or cirrhosis (Merck Manual). Current vaccination recommendations are available on the CDC website (ACIP). 

HEPATITIS B

Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). Hepatitis B spreads via an infected person's blood, semen, or other body fluids, typically through sexual contact, sharing needles, syringes, or other drug-injection equipment, or from mother to baby at birth. Symptoms can include fatigue, poor appetite, stomach pain, nausea, and jaundice. Some people experience no symptoms at all. Others may develop chronic liver infection (hepatitis) that can progress to liver cirrhosis or liver cancer (for more information, see CDC or WHO websites). No specific treatments exist for acute stage. Treatment of chronic hepatitis B is complex, long-term, and expensive (see AALSD guideline). Available vaccines that prevent hepatitis B are listed below.

HEPATITIS A, HEPATITIS B

Combination Hepatitis A and Hepatitis B vaccine (Twinrix) is used for active immunization of people 18 years and older. 

HUMAN PAPILLOMA VIRUS (HPV)

Human papillomavirus (HPV) is a group of more than 200 related viruses that cause warts. There are multiple different types of HPV, some causing skin warts, and others raised or flat genital warts. Some HPVs are spread through vaginal, anal, or oral sex. HPV is the most common sexually transmitted infection in the U.S. Low-risk HPVs cause no disease. Some low-risk HPV types can cause warts on or around the genitals, anus, mouth, or throat. There are about 14 high-risk HPV types that cause cancer. Two of these, HPV16 and HPV18, are responsible for most HPV-related cancers. HPV causes a significant proportion of cervical, oropharyngeal, anal, penile, vaginal, and vulvar cancers, accounting for 3% of all cancers in women and 2% in men in the U.S. (Merck Manual, Cancer.gov, CDC). Current vaccination recommendations are available on the CDC website (ACIP). 

INFLUENZA

Influenza (flu) is a viral infection caused by one of three basic types of influenza virus from the family Orthomyxoviridae: Influenza A, B, or C. Influenza A is generally more pathogenic than influenza B. The virus can cause mild to severe symptoms in most people. In some, the disease causes life-threatening complications, including death. Flu spreads mainly via droplets released through coughing or sneezing. Flu develops suddenly, and people experience fever, muscle and body aches, headache, chills, fatigue, cough, runny or stuffy nose, sore throat, vomiting, and diarrhea (more common in children than adults). Flu vaccines are updated annually to protect against the influenza viruses as they change. Influenza vaccines are recommended for people over 65 years of age and those with underlying medical conditions. Treatment is supportive. Antiviral drugs may sometimes be used (Medscape, NFID, CDC). Current vaccination recommendations are available on the CDC website (ACIP). 

JAPANESE ENCEPHALITIS

Japanese encephalitis is caused by the Japanese encephalitis virus (JEV) contracted through mosquito bites. Japanese encephalitis is endemic to big parts of Asia, including India, China, Japan and Korea, the Western Pacific, and the Torres Strait region of Australia. Most people have no or mild symptoms. Rarely the infection results in encephalitis, manifesting as severe headache, high fever, disorientation, coma, tremor, and convulsions. Japanese encephalitis has a case-fatality ratio of 20%–30%. One-third to half of the survivors have neurologic or other sequelae years later. The vaccine is recommended before travel to affected regions (ACIP, CDC, ACIP Recommendations). 

MEASLES, MUMPS, RUBELLA (MMR)

MEASLES (RUBEOLA). Measles is a highly contagious respiratory disease caused by the measles virus, a single-stranded, enveloped RNA virus of the genus Morbillivirus (family Paramyxoviridae). This virus is highly contagious, spread by coughing and sneezing. The measles infection can result in severe complications, including pneumonia, seizures, brain damage, and death. Risk factors include immunodeficiency due to HIV or AIDS, leukemia, cancer chemotherapy, or corticosteroid therapy. Up to 90% of the people close to an infected person will also become infected unless immune. Symptoms include rash, cough, runny nose, eye irritation, and fever. No specific treatment exists. The goal of treatment is to relieve symptoms and prevent complications (CDC, Medscape, Merck Manual).

MUMPS (epidemic parotitis). Mumps is an acute viral illness caused by Rubulavirus (genus Paramyxovirus, family Paramyxoviridae). The infection causes swelling of the salivary glands, typically the parotid glands. Symptoms usually consist of fever, headache, malaise, and ear pain aggravated by a chewing movement of the jaw. Some patients experience swelling of the thyroid gland or pancreatitis. Mumps can also cause oophoritis (inflammation of the ovaries) or meningitis. Orchitis is a common complication in adolescent and adult males, often resulting in testicular atrophy. Treatment is supportive, and no specific antivirals exist (Medscape, Merck Manual, CDC).

RUBELLA (German measles). Rubella is a contagious disease caused by the rubella virus (genus Rubivirus, family Togaviridae). Nearly half of infected people have no symptoms. Younger children display mild symptoms, such as rash and swollen lymph nodes. In older children, adolescents, and adults, rubella may be complicated by joint pain, arthritis, and thrombocytopenic purpura. Rarely rubella can cause encephalitis in children. The major complication of rubella is its teratogenic effects. If pregnant women contract the disease, especially in the early weeks of gestation, serious congenital defects, abortions, and stillbirths can occur (Medscape, Merck Manual, CDC).

In the U.S., two doses of the MMR vaccine are recommended for children. Infants typically get their first measles vaccine between 12 and 15 months, followed by another shot between 4 and 6 years. The mumps, measles, and rubella vaccines are bundled into one combined vaccine. A variant with varicella (ProQuad) is used as a second dose for children between 12 months and 12 years of age (See ACIP Recommendations for MMR, ACIP recommendations for MMRV). 

MENINGOCOCCUS

Meningococci (Neisseria meningitidis) are gram-negative cocci that cause meningitis and meningococcemia. There are 13 serogroups, of which six serogroups (A, B, C, W135, X, and Y) are responsible for most cases in humans. Serogroups B, C, and Y are the most prevalent in the U.S. Symptoms are usually severe, including meningitis, lethargy, and rash. Meningococci sometimes affect the lungs, joints, genitourinary organs, eyes, endocardium, and pericardium. The infection has a high fatality rate. Survivors can have permanent hearing loss, intellectual disability, or loss of phalanges or limbs. Treatment consists of antibiotics penicillin G or third-generation cephalosporines and dexamethasone. All children should receive MenACWY-D or MenACWY-CRM at age 11 or 12, with a booster dose at 16 (Merck Manual, Medscape, ACIP). 

PNEUMOCOCCUS

Streptococcus pneumoniae (pneumococcus) causes otitis media, pneumonia, sepsis, meningitis, and death. Pneumococci commonly colonize the human respiratory tract, particularly in winter and early spring. The infection spreads via airborne droplets. Outbreaks may occur in crowded settings. The pneumococcus capsule determines serologic type and contributes to virulence and pathogenicity. Most serious infections are caused by a small number of serotypes (3, 4, 6B, 9V, 14, 18C, 19F, and 23F) that are included in the vaccine. Pneumococcal diseases include otitis media, pneumonia, sinusitis, meningitis, endocarditis, and septic arthritis. Older people with chronic illness, immunodeficiency or immunosuppression, and residents of long-term care facilities are the most susceptible to severe infections. Treatment depends on the resistance profile and includes antibiotics (Merck Manual, ACIP). 

POLIOVIRUS

Poliovirus (enterovirus) causes acute infectious poliomyelitis. Symptoms vary from a nonspecific minor illness or aseptic meningitis without paralysis (nonparalytic poliomyelitis) to the less common yet very serious flaccid weakness of various muscle groups (paralytic poliomyelitis). Asymptomatic and minor infections (abortive poliomyelitis) are more common (about 60:1 compared to paralytic cases) and are the main source of spread. Paralysis can occur several days after the apparent resolution of the illness, especially in infants and young children. Common manifestations include deep muscle pain, hyperesthesias, paresthesias, urinary retention, and muscle spasms. Vaccination has almost eradicated poliomyelitis worldwide (Merck Manual, CDC, ACIP). 

RABIES

Rabies is viral encephalitis transmitted by the saliva of infected bats and other animals, such as raccoons, skunks, or foxes. Symptoms include depression, fever, agitation, drooling, and fear of water. Vaccination is indicated for people at high risk of exposure, such as veterinarians or speleologists. The infection is universally fatal once the brain becomes affected. The vaccine, in combination with rabies antiserum, can be administered after exposure to a rabid animal, almost always preventing the disease (Merck Manual, CDC, ACIP). 

ROTAVIRUS

Rotavirus is the most common cause of severe diarrhea in young children. Infants and toddlers aged 3 to 15 months are most commonly affected. Rotavirus is highly contagious. Adults often get infected by sick infants. Most infections occur in winter. Most infected children display fever, vomiting, and non-bloody, watery diarrhea. Treatment is supportive (Merck Manual, CDC, ACIP). 

SMALLPOX

Smallpox is a highly contagious disease with a fatality rate of about 30%. The smallpox virus (genus Orthopoxvirus) was eradicated in 1977. Routine vaccination in the USA was stopped in 1972 and globally in 1980. Smallpox remains a concern as a bioweapon (Merck Manual, CDC, ACIP). 

MONKEYPOX

Monkeypox is caused by the monkeypox virus (an Orthopoxvirus) structurally related to the smallpox virus. There are two distinct clades of monkeypox: the West African clade and the Congo Basin clade. The animal reservoir is unknown; however, the leading suspects are small rodents (e.g., squirrels) in the rain forests of Africa. Patients present with a vesicular or pustular rash that may be painful and often with fever, malaise, and swollen lymph nodes. An increase in incidence in Africa since 2000 is thought to be due to the cessation of smallpox vaccination in 1980. In 2003, an outbreak of monkeypox occurred in the U.S. due to infected rodents imported as pets from Africa spreading the virus to pet prairie dogs. In May 2022, monkeypox spread worldwide and was declared a public health emergency of international concern by the WHO. Monkeypox mainly affects the gay community, although not exclusively. Treatment is generally supportive and potentially with antiviral drugs. Prevention involves vaccination (Merck Manual, CDC, ACIP). 

TICK-BORNE ENCEPHALITIS

Tick-borne encephalitis (TBE) is an infectious disease involving the central nervous system. The virus (Flavivirus genus, family Flaviviridae) is not found in the U.S. but is widespread in many parts of Europe and Asia. Three different subtypes of the virus exist, each limited to a specific region. The disease is transmitted by a bite of infected ticks. The reservoir animals are mainly small rodents (voles, mice), insectivores, and carnivores. At first, the disease manifests as fever, fatigue, headache, muscular ache, and nausea. Later, meningitis and encephalitis develop. The European subtype is associated with milder disease, with 20–30% of patients developing encephalitis. Mortality reaches 0.5–2%. Severe neurological sequelae affect up to 10% of patients. The far eastern subtype is the most severe, with mortality rates of up to 35% and higher rates of severe neurological sequelae. The risk of contracting the disease can be reduced by repellents and wearing protective clothing during outdoor activities. Treatment relies on supportive management; no specific antiviral therapy exists (ECDC, CDC). 

TYPHOID

Typhoid fever, or enteric fever, is a potentially fatal multisystemic infection. The causal organisms are Salmonella enterica serotypes typhi and paratyphi A, B, and C. Salmonella can produce a variety of gastrointestinal infections. Some patients come down with overwhelming septic illness, while others experience diarrhea with low-grade fever. The typical symptoms are fever, malaise, diffuse abdominal pain, and constipation. Untreated typhoid fever may progress to delirium, obtundation, intestinal hemorrhage, bowel perforation, and death. Long-term or permanent neuropsychiatric complications may persist in some patients. Typhoid fever occurs in poor sanitation, crowding, and social chaos. Typhoid is treatable with antibiotics. Typhoid vaccine is recommended when traveling to areas with a high risk of exposure (Merck Manual, Medscape, ACIP). 

VARICELLA (CHICKENPOX)

Chickenpox is an acute childhood infection caused by the varicella-zoster virus (human Herpesvirus type 3). Herpes zoster (shingles) represents the reactivation of the latent phase. Chickenpox is extremely contagious, spreading by infected airborne droplets or aerosolized particles and direct contact. Chickenpox usually begins with mild symptoms followed by skin lesions appearing in crops. Chickenpox is rarely severe in immunocompetent children. Typical symptoms include mild headache, fever, and malaise, about 24 to 36 hours before lesions appear. The eruptions always involve the upper trunk and extremities and face in more severe cases. Ulcerated lesions may develop in the oropharynx and upper respiratory tract, conjunctiva, rectum, and vagina. Neurological complications, hepatitis, myocarditis, and bleeding may rarely develop post-infection. Antiviral drugs valacyclovir, famciclovir, or acyclovir are given to people with a risk of severe complications. Pregnant women are at risk of varicella complications (Medscape, Merck Manual, CDC, ACIP). 

YELLOW FEVER

Yellow fever is an infection caused by flavivirus (Group B Arbovirus) spread by mosquitoes. Yellow fever is endemic to tropical South America and sub-Saharan Africa. The virus is transmitted by the bite of an Aedes aegypti mosquito (urban variant) or forest canopy mosquitoes (jungle variant). Wild primates serve as an animal reservoir of yellow fever. Symptoms include sudden onset of fever, relative bradycardia, headache, jaundice, bleeding, and multiple organ failure. Some people have no symptoms; others develop a hemorrhagic fever that is often fatal. Vaccination is mandatory before traveling to certain regions (Merck Manual, Medscape, CDC, ACIP). 

ZOSTER (SHINGLES; ACUTE POSTERIOR GANGLIONITIS)

Herpes zoster is an infection that results when the varicella-zoster virus reactivates from its latent state. Symptoms usually begin with pain followed by a vesicular rash. Chickenpox and herpes zoster are caused by the same virus, varicella-zoster (human herpesvirus type 3). Chickenpox is the acute phase. Herpes zoster (shingles) represents the reactivation of the virus. Herpes zoster frequently occurs in older and immunosuppressed patients due to decreased cell-mediated immunity. Treatment is symptomatic. Antivirals (acyclovir, famciclovir, valacyclovir) can be used especially for immunocompromised patients (Medscape, Merck Manual, CDC, ACIP).