Cases of polio reported worldwide - Finnish vaccine protection against polio is good
In July, an unvaccinated person in the U.S. state of New York contracted polio, suffering paralysis. The disease was caused by a vaccine-derived poliovirus.
A genetically similar virus was also found in wastewater samples taken in London and the Jerusalem region during the spring and summer. However, no patients suffering from paralysis have been reported in these cities during intensified monitoring.
Local health authorities in these areas have recommended booster vaccines to improve polio vaccination coverage and stop the spread of the virus.
Polio was declared eradicated from Europe in 2002. Wild poliovirus (WPV) still occurs in Afghanistan and Pakistan. Individual cases have also been reported in Mozambique. In addition to the case in New York, cases of the disease caused by mutated, vaccine-derived polioviruses have also been reported this year in several Asian and African countries.
Vaccines containing live poliovirus are not used in Finland
Finns are well protected against polio. The polio vaccine that is used is Finland does not contain live viruses and it cannot be the source of infections from vaccine-derived poliovirus.
The vaccine is given free of charge as part of the national vaccine programme. Children are protected against polio by the 5-in-1 vaccine, which is administered at ages 3, 5, and 12 months old, and the protection is enhanced by a vaccination at 4 years of age. Coverage of polio vaccines among Finnish children is high - more than 98 percent.
Adults must also make sure that they have received three doses of polio vaccine in their lifetime.
THL monitors the occurrence of polioviruses in wastewater
Finland's most recent case of polio was found in 1985. The Finnish Institute for Health and Welfare (THL) is monitoring the possible spread of polioviruses in the population by examining wastewater samples for any presence of the viruses. Wastewater samples are collected regularly from five different cities. Approximately one third of the total Finnish population lives in the area of monitored sewer networks.
Based on the clinical picture, two faecal samples from suspected cases of polio are being examined in THL’s Expert Microbiology Unit.
Polio spread through respiratory tract or orally
It is possible to be infected by polio through the respiratory tract or orally. The virus passes through the digestive tract into the intestines, where it multiplies for several weeks. Occasionally the virus spreads from the intestines into the central nervous system, where it can harm nerve cells used for muscle activity, causing muscular paralysis and later atrophy.
The polio vaccine effectively protects against the form of the disease that causes damage to the central nervous system.
Further information
Carita Savolainen-Kopra
Head of the Expert Microbiology Unit
THL
+358 29 524 8884
[email protected]
Soile Blomqvist
Senior Researcher
THL
tel. +358 29 524 8490
[email protected]
Hanna Nohynek (vaccinations)
Chief Physician
THL
tel. +358 29 524 8246
[email protected]
