On 22 June 2018 the Government of Papua New Guinea (PNG) notified the World Health Organization of an outbreak of circulating vaccine-derived polio virus infection. As a result, a large-scale outbreak response and immunisation campaign is now underway in PNG.

As PNG is our close neighbour, people from the Northern Territory may visit the country for work or travel or to visit friends or family. Anyone travelling to PNG should ensure they are vaccinated as per current recommendations against this disease. People may think they are vaccinated if they have had their routine childhood vaccinations, but more is needed if travelling to PNG.

To be protected from polio, travellers will need a booster dose of inactivated poliomyelitis vaccine (IPV) if they have not had one during the last 10 years, before travelling to PNG.

What is polio?

Polio is short for poliomyelitis. It is a viral disease that is only present in a few countries around the world. Polio virus infection can cause paralysis and death.

 Anyone can develop polio if they are not vaccinated and travel to a part of the world where the virus still exists and they are exposed. Vaccination is the best protection against polio.

What is vaccine-derived polio?

Polio vaccines have been available for more than 50 years. It is estimated that more than 10 million cases of polio have been prevented since the administration of polio vaccines began.

There are two polio vaccines available:

• The oral polio vaccine (OPV) - a ‘live attenuated vaccine’ that contains a weakened form of virus. This is the vaccine used in PNG.
• The inactivated poliomyelitis vaccine (IPV) – this is a more expensive vaccine and is now used in Australia and given intramuscularly (as an injection). This vaccine cannot cause vaccine-derived polio.

OPV contains an attenuated (weakened) vaccine-virus, which activates the immune system in the body. When a person is immunised with OPV, the weakened vaccine-virus multiplies in the gut for a limited period, thereby developing immunity by building up antibodies in the gut and in the body. During this time the vaccine-virus is also excreted in the faeces. In areas of inadequate sanitation, this excreted vaccine-virus can spread in households and the immediate community.

On rare occasions, if a population is very under-immunised, an excreted vaccine-virus can continue to circulate for an extended length of time. In very rare instances, the vaccine-virus can genetically change into a form that can cause polio disease and paralysis in people who are not vaccinated against polio. This form is known as circulating vaccine-derived polio virus (cVDPV).

The risk of vaccine-derived polio virus developing is very small in comparison to the tremendous public health benefits of polio vaccination. Both OPV and IPV provide protection against cVDPV.

How is a vaccine-derived polio outbreak managed?

Vaccine-derived polio virus transmission can be rapidly stopped through a high-quality polio vaccination campaign. The solution is the same for all polio outbreaks:

• Immunise each individual to stop polio transmission, whether the virus is vaccine-derived or wild polio virus.
• By making sure that every individual is vaccinated with either IPV or OPV we can eradicate all types of polio.

What does this polio outbreak in PNG mean for NT residents?

Australia has been officially polio-free since 2000. The NT has high immunisation coverage of 92% at 4 years of age when the fourth dose of polio vaccination is given.

Because of our high vaccination rate, good sanitation and the ability of our health care system to respond to cases, polio is very unlikely to spread in Australia.

I plan to travel to or from PNG – what should I do?

Travelles to PNG should be fully vaccinated against polio to ensure their protection.

Recommendations:

• Travellers to PNG should have a booster IPV polio vaccine if they have not had one in the last 10 years.
• Travellers from PNG should have a booster polio vaccine within 4 weeks to 12 months of travel to Australia to boost immunity.
• Travellers to and from PNG are recommended to carry a hand held vaccination record of polio vaccines received.

For more information about polio in PNG and vaccination follow these links:

• http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-polio-PNG.htm
• https://beta.health.gov.au/services/polio-poliomyelitis-immunisation-service
• http://www.wpro.who.int/papuanewguinea/en/
• http://polioeradication.org/where-we-work/papua-new-guinea/
• https://smartraveller.gov.au/countries/pacific/pages/papua_new_guinea.aspx

Media contact: Tess Nekrasov 0427 596 954