(Photo credit: Heather Hazzan/ELF Magazine)
The Government has announced an emergency polio booster programme for all children aged 1 to 9 years old living in the Greater London area. This announcement comes after the virus was detected 116 times in the capital’s wastewater since February this year.
Following advice from the independent Joint Committee on Vaccination and Immunisation (JCVI), the NHS will be offering children aged 1 to 9 across the capital a polio vaccine booster dose, starting with the most impacted boroughs.
All children will be offered the vaccine, including children who are up-to-date with their vaccines. GPs will contact families within the next few weeks.
Whilst the risk for most of the population who are vaccinated remains “low,” healthcare workers have urged parents to ensure their children are fully vaccinated.
Although the detection of poliovirus in sewage water is cause for concern, the reason for the virus being there is due to the use of live polio vaccines abroad. Following a concerted vaccination programme to eradicate the disease worldwide, many countries have now been declared polio-free (including the UK).
However, there are still pockets of disease and outbreaks in a few remaining countries. In some of these regions, the oral polio vaccine is used during outbreaks that use a live, weakened version of the virus (that does not cause polio).
This is easy to distribute and gives a good immune response to protect against polio, thus, useful during outbreaks. However, it also has the potential to spread in areas where immunity from polio is low, such as in unvaccinated groups.
Whilst this can also increase immunity in the community, it could become a problem if the virus starts to spread, as it could potentially mutate and evolve from the safe version of the virus, used in the vaccines, to a more dangerous version capable of causing symptoms of polio.
Once countries are polio-free, they switch to the ‘dead’ virus vaccine, but the ‘live’ virus oral vaccines are still used in some countries, and this is what has been detected in London sewers; the virus that has come from using the oral vaccine elsewhere in the world.
The cause for concern is that some samples show signs of regaining the ability to cause symptoms such as paralysis-and genetic analysis suggests the virus has been spreading.
It is also related to samples found in wastewater in Israel and the US. In New York State, a young adult developed paralysis.
What is polio?
Polio is caused by a virus and can be spread from person to person via contact or contaminated food and water. Due to vaccination and better sanitation, polio disease is now rare.
The UK’s last case of natural polio was in 1984, and the UK and Europe were declared polio-free in 2003. In the UK, a ‘dead’ version of the virus is used in the childhood vaccination programme and has no risk of spreading.
This is the form of polio vaccine the UK has used since 2004 and will be used in the booster programme.
One of the first symptoms of polio is an upset stomach, hence why the virus can be detected in sewage water.
The UK Health Security Agency (UK HSA) says most of the samples detected are the safe vaccine form of polio, but “a few” have mutated enough to be dangerous.
The UK HSA also stated that genetic analysis of the samples suggests the spread of the virus “has gone beyond a close network of a few individuals”.
Most people who have polio have no symptoms, but some will experience flu-like symptoms such as hot temperatures, headaches, muscle aches, and stomach upset.
However, in a few infected individuals, polio can cause more serious symptoms, affecting the nervous system and inducing paralysis. This may not be permanent, and movement can come back over time, but it can be life-threatening if there is paralysis of the muscles used for breathing.
What are the current risks?
After concerns were raised in June about the detection of virus samples at Beckton Sewage Works in London, more analysis was conducted at other sites and the virus has been found in the following boroughs: Barnet, Brent, Camden, Enfield, Hackney, Haringey, Islington, and Waltham Forest.
Other countries, such as Belgium and Portugal, offer an additional dose as part of their childhood vaccination programmes, and the JCVI has considered international data on safety and effectiveness in forming their recommendation.
Overall, the UK has a high uptake of childhood vaccines, but there are pockets where uptake is lower. Across London, 15 per cent do not receive the three doses of vaccine in their first year of life (part of the polio, diphtheria, and tetanus vaccine).
However, in some boroughs this is higher and is estimated to be up to 40 per cent in some districts; these low rates could be one explanation why the virus is spreading.
Steve Barclay, Health, and Social Care Secretary said: “I recognise parents and guardians will be concerned about the detection of polio in London. However, I want to reassure people that nobody has been diagnosed with the virus and the risk to the wider population is low.”
Rachel Kayani
