Africa CDC deploys cross-strain vaccine amid accelerating DRC Ebola outbreak

The Africa Centres for Disease Control (Africa CDC) has announced the deployment of a vaccine designed for the Zaire ebolavirus strain to combat the current outbreak of the Bundibugyo strain in the Democratic Republic of Congo (DRC). Africa CDC Director-General Jean Kaseya stated that test cases indicate the vaccine provides a potentially life-saving level of protection, with zero deaths recorded among vaccinated individuals despite some symptoms. The outbreak, centred in eastern DRC, is spreading at a rate six to eight times faster than previous outbreaks, with over 4,000 confirmed cases and 1,801 deaths. Authorities also plan to expand the use of the antiviral drug remdesivir and conduct research into potential viral mutations.

The geographic scope of the crisis has widened significantly since the outbreak was declared in mid-May. Cases have now been logged in 51 health zones, up from just nine in May. The US health agency has issued a highest-level travel warning for the eastern provinces of Ituri and Nord-Kivu, citing historical instability and the severity of the disease. The advisory focuses specifically on these two provinces where the Bundibugyo virus disease outbreak is currently active, rather than the entirety of the DRC.

Kaseya highlighted a dramatic decline in contact tracing efficiency, a key metric for containing viral spread. In the DRC this year, there is one confirmed case for every 10 people on the contact list. This stands in stark contrast to the 2018–2020 Zaire strain outbreak, where one patient was identified from every 57 contacts, and in neighbouring Uganda, where the ratio was one in 41. Kaseya suggested that anyone in the hardest-hit city of Bunia or the worst-affected region of Ituri should be considered a potential contact, indicating a shift in containment strategy due to the virus's rapid transmission.

The urgency of the situation is compounded by logistical and security challenges. Kaseya was speaking from Brazzaville in the neighboring Republic of Congo after meeting with World Health Organization Director-General Tedros Adhanom Ghebreyesus in Kinshasa. He noted that authorities are launching studies to check for possible mutations or abnormalities in the current outbreak, given the unprecedented severity. The Africa CDC chief emphasized that while the vaccine eliminates deaths in test cases, it does not necessarily eliminate symptoms, marking a critical distinction in its application as a stop-gap measure.

Despite the rapid spread, health teams continue to screen for potential breaches in containment. Health teams screened more than 300 people on a river boat in Maluku, northeast of Kinshasa, after a passenger died with Ebola-like symptoms. The boat was reported to have come from Mongala province, where no cases have been reported, correcting earlier erroneous reports that it hailed from Kisangani. Neighboring Uganda reported 20 cases and two deaths, treating patients with remdesivir, while the DRC faces ongoing strikes by medical staff complaining of non-payment or inadequate conditions.