Vaccine-preventable diseases

Vaccination is the best, effective and safe way to combat infectious diseases. A vaccine provides protection to the vaccinated person and also indirectly to other people by reducing the spread of pathogens in the population. There is no specific medical treatment available for some of the diseases prevented by vaccinations.

High vaccination coverage protects those who have not yet reached the age of vaccination or are particularly vulnerable to the serious consequences of diseases. Diseases prevented by vaccination are particularly dangerous to those whose immunity has deteriorated either because of a disease or related treatment.

Vaccines have enabled completely or nearly completely eradicating several infectious diseases from Finland. This has also eliminated the secondary diseases, injuries and deaths related to the diseases. However, the diseases will return if immunisation coverage declines. 

Finland's national vaccination programme for adults and children

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Coronavirus SARS-CoV-2

Coronavirus usually causes a sudden respiratory tract infection. Symptoms may vary from none to severe disease. The symptoms may also fluctuate as the disease progresses. 
More information about coronavirus 


Rotaviruses are the most common pathogens causing severe diarrhoea and vomiting. In little children, this disease often leads to dehydration requiring hospital treatment. 

Rotaviruses spread very easily: when a person has diarrhoea, one gram of their faeces may contain up to 100 billion infective viruses. Rotavirus is highly resistant. It is easily transmitted from one person to another through, for example, hands, toys or other surfaces, as well as food or drink contaminated with the virus. 

More information about rotavirus (ECDC)

Pneumococcal diseases

Pneumococci are bacteria which cause upper respiratory tract infections, including sinus and middle ear infections. They may also cause serious symptoms requiring hospitalisation, including meningitis, pneumonia, bacteraemia and septicaemia.

The infection is spread as droplet transmission when carriers cough and sneeze. It may also be transmitted by contact. Many healthy people are nasopharyngeal carriers of pneumococci and may unwittingly spread the infection even if they are not personally ill. 

More information about pneumococci (ECDC)


Tetanus is a life-threatening disease caused by a toxin produced by the Clostridium tetani bacterium. Neurotoxins produced by tetanus bacteria cause restlessness, fever and headache. They also often cause stiffness of the jaw at the early stages. This is followed by other paralysis symptoms and spasms.

The bacteria can be found all over the world. It is common in the intestines of animals and in the soil, and its spores can be found on nearly any surface.

More information about tetanus (ECDC)

Whooping cough

Whooping cough, or pertussis, is a bacterial respiratory disease that occurs as epidemics. The disease is characterised by coughing spells that often end with vomiting. 

While whooping cough occurs in people of all ages, the disease is most dangerous to children under six months old. The coughing fits and breathing interruptions they may experience can be so severe that the child develops cerebral hypoxia, seizures or even brain damage, and may even die. 

Whooping cough is transmitted via droplets spread as a person coughs and also by hands as bacteria end up from a person’s hands to oral mucosa.

More information about whooping cough (European vaccination information portal)


Diphtheria is a severe inflammatory disease caused by bacteria. Its symptoms include severe throat pain, pharyngeal oedema and severe fever. The disease will quickly impair the person’s general health.  For instance, the toxin secreted by the bacteria can cause damage to the heart or nervous system. A person with diphtheria always requires hospital treatment.

Diphtheria is transmitted from one person to another through respiratory secretions, such as nasal discharge and saliva, and wound drainage. Infection requires close contact with a person who has the illness or carries the bacteria.

More information about diphtheria (ECDC)


Polio is a disease caused by the poliovirus. The infection is usually asymptomatic or the symptoms it causes are similar to a common cold. Poliovirus occasionally causes damage to the cells of the central nervous system and paralysis of the leg muscles, eventually leading to atrophy. 

Poliovirus can be contracted through the respiratory system. However, the disease is most commonly spread as viruses enter the intestines via hands, food or drink, and replicate there for several weeks. 

More information about polio (ECDC)

Hib diseases

The Hib bacteria cause various serious inflammatory diseases, particularly in early childhood, including meningitis, septicaemia, pneumonia, arthritis, osteitis and epiglottitis leading to airway obstruction.

The disease is transmitted by droplets or nasal and oral discharge. The infection can be spread by a symptomatic patient, an asymptomatic pharyngeal carrier of Hib bacteria or through objects such as toys.

More information about Hib (ECDC)


Measles is an inflammatory condition caused by a virus, or a generalised infection. Measles is a serious illness regardless of the patient’s age or condition. Youngest children and those with compromised immunity are at a particular risk. 

The most common secondary diseases include febrile convulsions, diarrhoea, ear infection, pneumonia and bacterial infections of the respiratory tract. Measles can also cause encephalitis. 

Measles is highly contagious through contact and droplet transmission and is also spread through the air. The disease spreads easily from a sick person. Measles viruses remain infective for up to two hours in an airspace or nearby surfaces after an infective person has left the space. 

More information about measles (European vaccination information portal)


Mumps is an infection of the salivary glands with fever caused by a virus. The secondary diseases for mumps include meningitis and encephalitis. It may also cause oophoritis, hearing damage and pancreatitis or carditis. 

Boys who have mumps after puberty may develop orchitis, which may lead to infertility.

Mumps is transmitted from one person to another through the respiratory tract by droplets. 

More information about mumps (ECDC)


Rubella is a highly contagious viral disease that causes rash. Its secondary diseases include arthritis and thrombocytopenia (low platelet count), which usually heal by themselves. Encephalitis (brain inflammation) is a rare secondary disease. A rubella infection, particularly during early pregnancy, may cause damage to the foetus, leading to, among other things, hearing damage, visual or cardiac impairment and developmental disability.

Rubella is transmitted from one person to another through the respiratory tract by droplets.

More information about rubella (European vaccination information portal)


Influenza is an acute inflammation of the upper respiratory tract caused by influenza viruses. Healthy working-age people often recover from influenza with home care. However, some people are at an increased risk of developing severe illness. Severe influenza is a serious condition that will quickly impair the person’s general health and may require hospital treatment. Influenza may also worsen the person’s chronic illness.

Influenza has several secondary diseases, such as ear infection, bronchitis and pneumonia. It also makes the person more susceptible to a myocardial infarction and cerebrovascular disturbances.

Influenza is transmitted to another person either through droplets as an infected person coughs and sneezes or through contact, for example by hands or as an infected person blows their nose. The disease is easily spread in confined spaces, such as day care centres, schools, public transport and institutions.

More information about influenza (ECDC)

Varicella (chickenpox)

Varicella (chickenpox) is an inflammatory disease of the whole body from which healthy children usually recover in around a week. 

The most common secondary disease in children is a severe bacterial infection of the skin caused by scratching the blisters. Other possible secondary diseases include pneumonia and encephalitis, which may cause permanent damage. 

For adults, varicella is often a severe disease. Varicella infection during pregnancy is a serious disease for both the mother and the foetus. After a varicella infection, the virus remains in the body and may later cause shingles, a painful blistering disease.

Varicella is highly contagious. The virus spreads from the infected person’s respiratory tract and blisters by air, droplets and direct contact. It can only take little time spent in the same room with a person infected with varicella for a person susceptible to the disease to contract it. 

More information about varicella (chickenpox) (ECDC)

Human papillomavirus infection

The human papillomavirus (HPV) can cause many different cancers and serious harm to both women and men. HPV causes cancers of the cervix, vagina and vulva, and the anus, penis, and head and neck. 

Human papillomaviruses are highly common. Without a vaccine, almost everyone is infected at an early age. The virus is transmitted through the skin and mucous membranes, usually through intercourse. However, it is possible to get the infection even without having actual intercourse, as the virus is not only transmitted through mucous membranes but also the skin surrounding the genitals.

More information about the human papillomavirus (European vaccination information portal)


Tuberculosis is an infection caused by bacteria. Pulmonary tuberculosis is the most common form of tuberculosis. However, it can occur in any part of the body. Young children are highly susceptible to a tuberculosis infection. The infection can lead to a very serious disease in them.

Aerosol droplets containing tuberculosis spread into the air when a person with infectious pulmonary tuberculosis is coughing or talking. Other people are exposed to the virus when breathing in the same space.

More information about tuberculosis (WHO)

Hepatitis A and B

Hepatitis A and B viruses cause hepatitis (liver inflammation). However, these two viruses have different modes of transmission and symptoms. A small proportion of those infected with hepatitis B remain carriers of the virus, or develop a chronic infection. The chronic infection can lead to liver failure, which increases the risk of liver cirrhosis and liver cancer.

The hepatitis A virus spreads through contaminated food and drinking water. Persons with a hepatitis A infection shed great quantities of the virus to their faeces. Poor hand hygiene may allow the virus to spread in foods, from different surfaces and from person to person, for example in sexual contact. 

Hepatitis B spreads from one person to another in blood-to-blood and sexual contact. Hepatitis B may also be transmitted from a mother to a child during labour or breastfeeding. 

Intravenous drug users may be infected with Hepatitis A or B through the equipment used to inject drugs.  

More information about hepatitis A (ECDC)

More information about hepatitis B (ECDC)

Tick-borne encephalitis

Tick-borne encephalitis is an inflammation of the brain caused by the TBE virus. Tick-borne encephalitis occurs in a wide area from Central Europe through Siberia to Japan. 

The TBE virus spreads through a tick bite. Transmission is caused by tick saliva, occurring in just a few minutes since a person has been bitten by a tick. Infections caused by unpasteurised milk have also been reported in the Baltic countries and in Central Europe. 

More information about tick-borne encephalitis (ECDC)

What to do if a tic bites you (pdf  5.16 MB)

Test your knowledge of diseases transmitted by ticks

Do you know what causes borreliosis or what proportion of ticks carry encephalitis in risk areas? Where are ticks found and how should you protect yourself from them?

Test your knowledge and find out whether you belong to the elite of tick experts or whether you should still improve your expertise. 

Test your knowledge here

Meningococcal Diseases

Meningococcal diseases are rare, life-threatening illnesses caused by bacteria called meningococcus or Neisseria meningitidis. These illnesses are always severe and include infections of the brain and spinal cord (meningitis) and bloodstream (bacteraemia and septicaemia). 

Meningococcal infection is spread in close contacts from person to person by respiratory droplets or throat secretions. Close, prolonged contact, such as kissing, sneezing, coughing, or living with a person who has the illness or carries the bacteria in their throat, promotes the spread of the bacterium. Transmission is facilitated during mass gatherings and other overcrowded situations, including cramped accommodation. 

Close contacts of a person with meningococcal disease should receive antibiotics to help prevent them from getting the disease.

More information about meningococci (ECDC)