25 Oct 2019
Chad, Togo and Zambia: updated recommendations for polio vaccinationCirculating vaccine-derived poliovirus type 2 has been confirmed by the World Health Organization in these African countries
On 17 October 2019, a case of circulating vaccine-derived poliovirus type 2 (cVDPV2) was confirmed in a two-year-old child in Chienge district, Luapula province, Zambia near the border with Democratic Republic of the Congo. This is the first cVDPV2 case reported from Zambia in 2019. Samples taken from two healthy case contacts in Zambia were positive for cVDPV2 and genetic testing has connected them to the initial case. The last recorded case of locally acquired wild poliovirus (WPV) in Zambia was in 1995 .
On 18 October 2019, a cVDPV2 case was confirmed in a 13-month-old baby with acute flaccid paralysis (AFP) in Chari Baguirmi province, bordering Cameroon. This case has been genetically-linked to cVDPV2 detected in Borno, Nigeria. The last locally acquired WPV case in Chad was reported in 2000 .
On 18 October 2019, a cVDPV2 case was confirmed in a 30-month-old child with AFP in Plateaux province, bordering Benin and Ghana. This case has been genetically linked to cVDPV2 detected in Irewole, Nigeria. The last locally acquired WPV case in Togo was reported in 1999 .
Multiple cVDPV2 outbreaks in Africa with international spread are now at an unprecedented level. Risk of new outbreaks in new countries is considered extremely high, even probable .
Worldwide efforts to protect children with oral polio vaccine (OPV) have reduced WPV cases by 99.9% since 1988. OPV is safe, effective and interrupts person-to-person WPV spread. However, in poorly vaccinated populations the live weakened polio virus in OPV can mutate into cVDPV. Like WPV outbreaks, cVDPV outbreaks can be stopped with high-quality vaccination campaigns .
Eradication of cVDPV is an important part of the World Health Organization’s strategy to end polio transmission worldwide .
Advice for travellers
CVDPV can be transmitted via the faecal-oral route, through exposure to water contaminated by infected human faeces, or by direct person to person contact. You are advised to practise strict food, water and personal hygiene.
Independent of your travel destination, you should be up to date with routine vaccination courses and boosters, as recommended in the UK.
If you are travelling to Chad, Togo or Zambia make sure you have completed a full course of a polio-containing vaccine. Polio vaccines used in the UK provide protection against all types of poliovirus. If your last dose of polio vaccine was given 10 or more years ago, make sure you have a booster dose before travel.
Children who are travelling should be up to date with an age appropriate course of polio vaccine.
For specific outbreak information, check our Outbreak Surveillance database.
The polio status of countries is reviewed by World Health Organization on a regular basis and polio vaccination recommendations are subject to change. For individual country specific advice, check our Country Information pages.
Further details on the worldwide polio situation are available from the Global Polio Eradication Initiative.
- World Health Organization Regional Office for Africa. Weekly Bulletin on outbreaks and other emergencies. Week 42:14-20 October 2019. [Accessed 25 October 2019]
- World Health Organization. Statement of the Twenty-Second IHR Emergency Committee Regarding the International Spread of Poliovirus. 3 October 2019. [Accessed 25 October 2019]
- Global Polio Eradication Initiative. Factsheet: Vaccine-derived polioviruses. September 2017. [Accessed 25 October 2019]
- World Health Organization. Polio Endgame Strategy 2019 -2023: Eradication, integration, certification and containment. April 2019. [Accessed 25 October 2019]