The history of vaccines in the United States is a remarkable story of progress and innovation, marked by the development of numerous life-saving vaccines that have greatly reduced the incidence of infectious diseases. In the decades prior to the first successful vaccine, Americans had little protection against deadly diseases like smallpox, measles, and diphtheria. The introduction of vaccines has led to a dramatic reduction in the number of illnesses, infections, and deaths from these diseases.
Smallpox, a highly contagious viral disease, was one of the world's deadliest diseases before vaccination. The first successful vaccine, developed by English physician Edward Jenner in 1796, eventually transformed public health in the United States. The smallpox vaccine ultimately led to the global eradication of smallpox, according to the World Health Organization. The vaccine is no longer given routinely to the public and is mainly used for select military, laboratory, and emergency-response needs.
A viral disease that attacks the brain and nervous system, rabies spreads through the saliva of infected mammals, most commonly through the bites of dogs, bats, raccoons, skunks, and foxes. Although there is no cure, vaccination immediately after exposure can prevent the disease. It can also be given before exposure for people at high risk. Researcher Louis Pasteur created the first rabies vaccine in 1885. Today, prompt vaccination after exposure remains the standard way to prevent an otherwise almost universally fatal disease.
Diphtheria is a bacterial infection that can cause a thick coating in the throat. It was fatal for some, and survivors could face serious complications, including heart damage, paralysis, and breathing problems. The diphtheria toxoid vaccine was introduced in the 1920s. Diphtheria is now extremely rare in the U.S. due to widespread vaccinations. The vaccine remains part of the routine childhood immunization schedule as part of the DTaP series, with boosters recommended for teens, adults, and pregnant women.
Tetanus is a bacterial disease caused by Clostridium tetani, which enters the body through cuts or wounds. The infection can cause severe muscle spasms, "lockjaw," and death. The tetanus toxoid vaccine was developed in the 1920s. Tetanus vaccination remains part of the routine childhood immunization schedule, with boosters recommended every 10 years and as needed following certain wounds.
Whooping cough (pertussis) is a highly contagious bacterial infection that causes severe coughing fits, often making it difficult to breathe, eat, or sleep. Infants are at highest risk, as they can develop pneumonia, seizures, brain damage, or even death. The first pertussis vaccine was introduced in the 1910s, followed by the combination DTP (diphtheria, tetanus, and pertussis) vaccine in the 1940s. Following widespread vaccination, cases fell by more than 90%, and deaths from the disease became uncommon.
Influenza is a contagious viral respiratory illness that can cause serious complications, hospitalization, and death. Before the vaccine was available, seasonal flu epidemics caused widespread illness and death every year. The first U.S. flu vaccine was licensed in 1945, helping launch routine seasonal influenza vaccination programs. Widespread vaccination has significantly reduced the risk of flu illness, hospitalization, and death.
Polio (poliomyelitis), a highly contagious viral disease caused by poliovirus, spreads mainly through contact with contaminated food, water, or stool. For some, the virus can attack the nervous system, causing permanent paralysis, breathing difficulties, and death. Jonas Salk's polio vaccine was introduced in 1955, greatly reducing case counts. In 1979, the U.S. was declared free of wild poliovirus.
Measles, mumps, and rubella were common childhood diseases that infected millions of Americans and could cause serious complications. The measles vaccine was introduced in 1963, followed by mumps in 1967 and rubella in 1969. In 1971, the MMR (measles, mumps, and rubella) vaccine became available, protecting against all three contagious viral diseases in a single shot. Prior to the combined vaccine, children typically had to receive three separate shots.
Hepatitis B, a viral infection that attacks the liver, is spread through contact with infected blood and other body fluids. Some people develop chronic hepatitis B, which can lead to cirrhosis, liver failure, and liver cancer. The hepatitis B vaccine was licensed in 1981, and the CDC began recommending universal infant vaccination in 1991. Since then, acute hepatitis B cases have declined by more than 80%, and infections among children and adolescents have fallen by more than 95%.
Haemophilus influenzae type b (Hib) is a bacterial infection that can cause pneumonia, meningitis, bloodstream infections, and severe throat swelling. The first Hib vaccine was licensed in 1985, with routine immunizations reducing invasive disease by more than 99%. The infection is now rare in the U.S.
Chickenpox (varicella) is a highly contagious viral disease caused by the varicella-zoster virus that causes an itchy, blister-like rash, fever, and fatigue. In some people, it can lead to serious complications, including pneumonia, brain inflammation, and bacterial skin infections. The first chickenpox vaccine became available in the U.S. in 1995. Since routine two-dose childhood vaccination began, hospitalizations and deaths have declined by more than 90%, and severe complications have become rare.
Hepatitis A is a highly contagious viral liver infection that spreads mainly through contaminated food or water or close contact with an infected person. While it does not cause chronic liver disease like hepatitis B, it can cause weeks or months of illness and, in rare cases, liver failure. The first hepatitis A vaccine was licensed in the U.S. in 1995. Since routine childhood vaccination began, infection rates have dropped by more than 95%.
Pneumococcal disease, caused by the bacterium Streptococcus pneumoniae, can lead to pneumonia, meningitis, bloodstream infections, ear infections, and sinus infections. The first pneumococcal conjugate vaccine was licensed in 2000. Routine childhood vaccination has dramatically reduced disease rates, and newer vaccines have been developed to protect against emerging bacterial strains.
The human papillomavirus (HPV) is the most common sexually transmitted infection in the U.S. It can cause cervical, anal, penile, vaginal, vulvar, and oropharyngeal cancers. The HPV vaccine was licensed in 2006, becoming the first immunization designed to prevent multiple types of cancer. Since the vaccine became available, HPV infections, precancers, and genital warts have declined significantly.
Rotavirus is a highly contagious virus that primarily affects infants and young children, causing severe diarrhea, vomiting, and fever. The first rotavirus vaccine became available in 2006. Since routine vaccination began, hospitalizations, emergency room visits, and severe illness have declined significantly. Infants receive two or three oral doses as part of the routine immunization schedule.
Shingles is a painful rash caused by reactivation of the varicella-zoster virus, the same one that causes chickenpox. It can cause severe nerve pain lasting months or even years. The first shingles vaccine was licensed in 2006, and the more effective Shingrix vaccine was introduced in 2017, greatly reducing the risk of shingles and long-term nerve pain.
The COVID-19 pandemic spread worldwide in 2020, and there was no vaccine to prevent severe illness from the infection, which is caused by the SARS-CoV-2 virus. The first COVID-19 vaccines received emergency authorization in December 2020. Multiple studies have shown that the vaccines significantly reduce the risk of severe illness, hospitalization, and death, particularly among high-risk groups.
The impact of vaccines in the United States has been profound, greatly reducing the incidence of infectious diseases and saving countless lives. People should contact a doctor to discuss individual recommendations for vaccines, which can vary by age, health status, medical history, and risk factors.
