Developing a new vaccine is a process that usually takes several years. The goal is to produce a vaccine that provides effective and safe protection from a serious disease and its sequelae.
- All vaccines may have side effects. The majority of the side effects of being vaccinated are mild, harmless and short-lived localised symptoms at the point of injection, or perhaps a low-grade fever. These symptoms only affect a proportion of those who get vaccinated. The benefits of vaccinations outweigh their disadvantages.
- Vaccinations may have various side effects that differ between vaccines. Only a small proportion of those who are vaccinated experience these side effects. The majority of the symptoms are mild and short-lived. The health care professional who administers the vaccine provides information on the side effects at the time of vaccination to help the patient prepare for them.
- Not all symptoms experienced after being vaccinated are necessarily linked to the vaccination.
- The least common side effects are only revealed once a vaccine is widely used.
- The 2009 swine flu epidemic was followed by an increase in narcolepsy cases. Based on current information, the development of narcolepsy among vaccinated people was the result of a genetic predisposition combined with the Pandemrix vaccine. The link between the Pandemrix vaccine and narcolepsy is still being studied.
- While the narcolepsy cases were extremely regrettable, the Pandemrix vaccine also had its advantages. The National Institute for Health and Welfare estimates that the vaccine prevented about 80,000 cases of influenza and approximately 50 swine-flu related deaths.
- CDC, Narcolepsy Following Pandemrix Influenza Vaccination in Europe
- Duodecim medical reference book: Swine flu pandemic 2009–2010 and narcolepsy after vaccinations (in Finnish)
- Duodecim medical reference book: Adverse effects and risks of vaccinations (in Finnish)
- NHS, National Health Service: Why vaccination is safe and important
- THL, Adverse effects of vaccinations
- THL, Immunisation: Vaccine research (in Finnish)
- THL, Why are vaccinations needed?
Page published 30.4.2018
Page edited 1.12.2022