The immediate news is that two vaccine candidates may join an ongoing trial in the Democratic Republic of the Congo, or DRC.

A study that is already continuing is an ongoing trial.

WHO says there is no vaccine licensed for Bundibugyo virus disease.

Here, licensed means officially approved for use.

Ervebo is licensed for Ebola virus disease, but WHO says evidence is not enough to know whether it protects people against Bundibugyo virus.

Here, licensed means officially approved for use against this disease.

WHO described transmission as widespread.

The virus was spreading across a large area.

That is a meaningful step in the search for protection, while the outbreak remains widespread and the candidates are still unproven.

The outbreak is still affecting a large area.

Expert groups convened by WHO recommended adding them to the Tumaini trial.

The groups were brought together for a meeting by WHO.

It uses ring vaccination, which means offering vaccination to people who had contact with a confirmed case.

This means offering vaccines to people around a confirmed case, to help stop the virus spreading.

WHO says it builds on ring vaccination used during the West Africa Ebola outbreak about a decade ago.

This is vaccination offered to people who had contact with a confirmed case.

Contacts are people who may have been exposed to someone with the disease.

They may have come into contact with the virus through a sick person.

WHO says research should be conducted in close consultation with affected communities.

Researchers should discuss the work carefully with the communities affected.

WHO says it builds on ring vaccination used during the West Africa Ebola outbreak about a decade ago.

The current work uses an earlier approach as a starting point.

WHO says the response still relies on surveillance, rapid testing, contact tracing, isolation and care, infection prevention, community engagement, and safe burials.

This means finding people who had contact with someone who has the disease.

Grace, how should listeners weigh the promise of vaccines against those measures?

Here, weigh means consider and compare the value of vaccines and the other measures.

That is a meaningful step in the search for protection, while the outbreak remains widespread and the candidates are still unproven.

The candidates have not yet been shown to work.