The World Health Organization (WHO) is set to vaccinate about 200 people in Sierra Leone, who were believed to have been directly or indirectly exposed to a woman who succumbed to death due to the virus on Saturday, Aug. 29.

The 67-year-old woman, whose diagnostic test results came positive for Ebola, was a merchant from the Kambia District, which is close to the border of Guinea. She died five days after Sierra Leone has begun a countdown projected to last for 42 days before the country may be declared free from the deadly virus. Before her diagnosis, the last patient diagnosed with the disease was reported on Aug. 8.

Because of the latest Ebola death, the country's efforts to halt the outbreak that has been striking the nation for 18 months have been set back. Ebola virus has already infected about 28,000 individuals in the countries of Sierra Leone, Guinea and Liberia, with deaths reported in more than one third of the entire morbidity records.

WHO will immunize the people in the area of Tonko Limba who have had direct and indirect exposures to the deceased, says Margaret Harris, a spokesperson from WHO. This effort will also include people who have had close contacts with the said exposed individuals. The authorities will have to guarantee that all the affected individuals will be given adequate information and that they will all agree with the vaccination, she adds.

According to Harris, the outcomes of the voluntary immunizations with a vaccine that arrived and had been effective in Guinea will begin on either Thursday, Sept. 3 or Friday, Sept. 4.

The newest case of Ebola virus in the country is a letdown and serves as a sign that Ebola is such a tough challenge to overcome, says Pallo Conteh, leader of Sierra Leone's National Ebola Response Center. Perhaps, more infected individuals may come up due to the fresh case. He now calls out to the niece of the latest death case to report as she is at a high risk.

Ebola virus was first announced in March 2014 and has worsened since then. In May 2015, Liberia has been declared free of the disease about after about two months, a batch of cases had been detected. On July 23, the last patient in Liberia's latest outbreak was already discharged.

According to experts, the most probable source for the recurrence of the virus in Liberia was sexual transmission. This is because the viral pathogen can settle in the semen far longer than its incubation period of 21 days.

Photo: National Institute of Allergy and Infectious Diseases | Flickr