Planned mass vaccination of some 26.2 million people against yellow fever got underway across the country on November 22.

It is the second phase of a massive campaign to establish high population immunity to yellow fever nationwide which ends December 1.

Funded by the Global Alliance for Vaccine Initiative (GAVI), the present campaign targets all ages between nine years and 44 years in Plateau, Sokoto, Kebbi, Niger and Borno states as well as the Federal Capital Territory.

“Parents are advised to avail themselves and their children to partake in the vaccination; the vaccine is free, safe and effective,” said Dr Joseph Oteri, Director of Special Duties at Nigeria’s National Primary Health Care Development Agency.

Both the agency, the World Health Organisation and the United Nations Children’s Fund, support the campaign.

A virus spread through the bite of infected mosquitoes cause yellow fever.

Serious symptoms include high fever and jaundice (yellowing of the skin and eyes), but the disease can be easily prevented by a vaccine that provides immunity for life.

“Immunizing more than 26 million people is a massive undertaking,” said Dr Matshidiso Moeti, WHO Regional Director for Africa.

“But this achievement will represent a huge step towards protecting people from the potentially deadly viral haemorrhagic disease not only in Nigeria but in the African region.”

The federal health ministry has trained and deployed support teams to oversee preparations in the run-up to the campaign.

The teams will also supervise and offer technical assistance during the campaign.

“Nigeria is on the front line in the global battle against yellow fever,” said Dr Seth Berkley, CEO of Gavi, the Vaccine Alliance.

“Routine immunisation coverage remains dangerously low, as shown by the latest outbreak, which is why this campaign is so important to protect the vulnerable. While this campaign will save lives, we need to focus our efforts on the best long-term solution – improving routine immunisation coverage so every child is protected, preventing outbreaks from happening in the first place.”

The first phase of this yellow fever preventive mass vaccination campaign (PMVC) took place in January and February 2018 in Kwara, Kogi and Zamfara states and parts of Borno state.

Approximately 8.7 million adults and children between the ages of 9 months and 45 years of ages were vaccinated. A total of 39.9 million people are expected to be vaccinated against yellow fever this year.

An outbreak of yellow fever has been ongoing since September last year.

Infections have been confirmed in 27 Local Government Areas across 14 states.

Nigeria is one of the 50 partners pursuing the Eliminate Yellow Fever Epidemics (EYE) strategy, to protect populations at risk, prevent international spread and contain outbreaks rapidly.

As part of EYE, Nigeria has developed a 10-year strategic elimination plan to reduce the incidence of yellow fever epidemics and to vaccinate at least 80% of the target population in all states by 2026.

Routine immunisation against yellow fever is low: only around four in 10 children aged up to two years were immunised.

Gavi support for the campaign is part of pledge it made to support routine immunisation after Nigeria committed to invest $2billion in immunisation over the next 10 years.

Large epidemics of yellow fever occur when infected people introduce the virus into heavily populated areas with high mosquito density and low vaccination coverage.

A confirmed case of yellow fever in an unvaccinated population is a potential epidemic threat.