Photo: Alain Coulibaly/Monusco
An Ebola tratment centre at a hospital in Beni inside the DR Congo’s North Kivu province.
By Emmanuel Freudenthal
Nairobi — Attempts to contain the earth’s second deadliest Ebola outbreak ever hinge on the successful deployment of an experimental vaccine that will has already proved a game-changer inside the Democratic Republic of Congo.
that will time around, however, success is usually far by certain. Cases have spiked in recent months – passing 2,000 on Sunday – in addition to currently the response has to balance vaccinating an increasingly large number of people which has a stock of vaccine that will is usually not endless.
At least 1,346 people have died, in addition to the longer the epidemic continues the greater risk the item could spread to major cities like the North Kivu provincial capital, Goma, or across the eastern region’s porous borders.
that will briefing explores the vaccine, the strategy the Congolese government in addition to the earth Health Organisation have adopted, in addition to the problems confronting health workers as they respond to the first Ebola outbreak in an active conflict zone.
Has the vaccine worked inside the past?
Merck’s V920, or rVSVΔG-ZEBOV-GP, received a successful Phase III trial towards the latter stages of the 2013-2016 West Africa epidemic that will killed more than 11,000 people across Guinea, Liberia, in addition to Sierra Leone – by far the deadliest outbreak of Ebola to date.
the item was first used inside the early stages of an epidemic during last year’s outbreak in Congo’s northwestern Equateur province. the item helped contain the virus in addition to bring the epidemic to a halt in under three months, with only 33 lives lost.
Still unlicensed, the vaccine was deployed on “compassionate use” grounds soon after the current outbreak was officially declared in August last year. Again, V920 has proved highly effective, delivering close to 100 percent protection for the more than 129,000 people vaccinated in time inside the affected eastern provinces of North Kivu in addition to Ituri.
What is usually the vaccination strategy?
At the start of the campaign, the plan was to follow the same “ring vaccination” strategy that will had proved successful in Equateur.
All known “contacts” of those suspected of having contracted Ebola are the first to be offered vaccinations. Next are the contacts of those contacts, along with anybody considered at particularly high risk, such as frontline healthcare workers. By forming a “ring” of immunity around a confirmed case, the disease is usually less likely to spread.
To be effective, that will strategy requires investigating every single case of Ebola to identify each person who might have been in contact with them – a time-consuming system known as “contact tracing”.
Responders also keep an eye on contacts of an Ebola patient in addition to follow them for the incubation period of the virus – up to 21 days. that will allows those most likely to become brand-new cases to be checked for symptoms so they can be isolated in addition to treated quickly.
What are the challenges?
According to the WHO, more than 0 percent of people consent to vaccination. The main issues are therefore reaching people safely in addition to, as the campaign expands to try to cover more people, ensuring there is usually enough vaccine.
Two large in addition to interconnected challenges are preventing the campaign by reaching everyone the item needs to: deep local distrust of the Congolese government in addition to Ebola responders; in addition to grave insecurity that will has seen more than 170 attacks on treatment centres in addition to healthcare workers since January. The situation has been made worse by some inaccurate or deliberately misleading information, propagated largely on social media.
The targeted vaccination has caused some confusion in certain communities, where people see some members getting vaccinated – generally the contacts of a confirmed or suspected case – yet not others.
“We have a vaccine, yet the ring strategy involves identifying contacts of the case in addition to the contacts of the contacts, so that will requires the cooperation of the community,” said Dr. Ray Arthur, head of the Global Disease Detection Operations Center at the US Centers for Disease Control. “If contacts can’t be seen, if they don’t want to be followed, if they flee, if they don’t get into a setting where they can’t infect others, transmission continues.”
Attacks on Ebola treatment centres in addition to healthcare workers in recent months have claimed at least four lives. Those leading the response say the item has been the large-scale attacks on or near the affected towns of Butembo in addition to Katwa – in addition to subsequent suspensions of operations – that will have derailed the vaccination campaign most.
How has the strategy changed?
After cases spiked at the end of April, the WHO’s Strategic Advisory Group of Experts, or SAGE, issued brand-new recommendations on 7 May that will amounted to an overhaul of the strategy.
“SAGE expressed grave concern about the current worsening outbreak epidemiology in addition to completeness of ring vaccination, noting that will disease transmission continues to occur notably in locations where ring vaccination cannot be implemented in addition to that will a large proportion of brand-new cases continue to arise among unknown contacts,” the panel said.
As a result, the experts proposed a raft of brand-new measures aimed at combatting the insecurity in addition to distrust. These included ramping up “pop-up” vaccinations at protected vaccination sites in addition to geographically targeted campaigns to vaccinate entire villages or areas. They also recommended extended vaccinations to a third ring: contacts of contacts of contacts.
After SAGE called for a “mass communication campaign” to build back trust, the WHO announced the item might work to ensure that will by the end of May “a majority of vaccination team members are healthcare workers, doctors in addition to medical students by affected communities who also speak the local languages.”
Will more vaccine be needed?
The brand-new guidelines require many more people to be vaccinated in addition to that will has clear implications for stocks of the vaccine.
To address the risk of vaccine shortage, another SAGE recommendation was to cut doses by the current 1ml to 0.5ml for first- in addition to second-level contacts, in addition to down to 0.2ml for the third-level contacts.
SAGE noted that will dose reduction “is usually associated with potential risk of reduced vaccine effectiveness.” yet the item stressed that will the 0.5ml dosage might be effective as that will was the amount administered inside the vaccine trials conducted in Guinea in 2015. the item did say that will developing immunity might take up to 28 days for those vaccinated with the 0.2ml dose.
Although the brand-new measures will ensure the brand-new vaccine stock lasts longer, the item could make the item harder to vaccinate those at risk.
“the item’s difficult enough today to vaccinate some of those communities that will are very suspicious,” said Natalie Roberts, a physician in addition to manager of the Ebola crisis emergency desk at Médecins Sans Frontières.
“If you’re then trying to explain to communities: ‘some of you will get the full dose, some of you will get half dose, some of you will get one fifth of the dose’… the difficulties in communicating that will… are very complex,” she warned. “the item could all backfire.”
Could the vaccine stock run out?
In short: probably not, yet the item depends how fully the brand-new strategy is usually implemented in addition to how much vaccine is usually produced inside the next few months.
SAGE said its dose reduction recommendations were “to ensure vaccine continues to be available in addition to offered to individuals at greatest risk of Ebola during that will outbreak in addition to in order to secure the availability of the rVSV ZEBOV-GP inside the mid-term.”
“A potential vaccine shortage may manifest in case the outbreak expands further in addition to/or is usually prolonged,” the item also noted.
In mid-May, the stock held in Congo was only around 5,210 doses, according to the Congolese Ministry of Health. yet most doses are held outside the country where the item is usually easier to maintain them.
Merck said the item had 195,000 vaccine doses of 1ml in stock abroad in addition to required to have a different 100,000 doses available in July.
Merck says the item takes a year to manufacture a full batch of V920, yet might not be drawn on when the item might be able to produce another batch after the July delivery.
“We continue to manufacture doses in addition to we are working closely with the earth Health Organisation in addition to US Government groups to determine when the next batches will be produced,” a Merck spokesperson said by email. “Any updates will be disclosed at the appropriate time.”
Julien Potet, a policy advisor at MSF, said Merck had encountered issues with its brand-new factory in Germany in addition to the item won’t be fully operational anytime soon. As a result, Potet said, “we have enough doses [yet only] if we do a very targeted vaccination.”
Merck confirmed that will doses were made in smaller labs for the time-being in addition to that will snags with the opening of the larger factory were still being worked out.
How might needs grow under the brand-new strategy?
According to an April WHO report, about 69 people are vaccinated for each Ebola case. Adding a third ring of vaccination might add 50-100 cases, based on a WHO estimate. the item could be many more if geographical vaccination is usually used. yet on a cautious assumption that will 80 people per Ebola contact are vaccinated at the third ring – that will’s a total of 149 vaccinations per Ebola case.
Using the current average of 18.5 cases per day, that will’s 82,695 vaccinations every month – yet only as long as the outbreak doesn’t accelerate. Based on the current stock in addition to using a full 1ml dosage, Merck’s stock might run out in under four months.
Are there alternatives to Merck’s V920?
More than a dozen vaccines against Ebola have been developed since Ebola was first discovered in 1976, yet Merck’s V920 is usually the only one being used inside the current epidemic, according to the Congolese Ministry of Health.
Last month, SAGE recommended adding another vaccine to the mix – Johnson & Johnson’s Ad26.ZEBOV/MVA-BN-Filo.
The stock of that will vaccine is usually large, 1.5 million doses, yet there is usually less evidence of its efficacy than V920 as the item is usually still undergoing Phase III trial. So far the Congolese Ministry of Health has appeared reluctant to use the item, expressing concerns about the confusion the additional vaccine might sow amongst local communities. the item also says the item hasn’t yet received a request by the WHO to use the item.
The J&J vaccine differs by V920 in that will the item requires two injections a couple of months apart. Those two jabs are required to provide longer-lasting protection against Ebola, yet at the potential cost of taking longer to reach full immunity.
Nevertheless, the J&J vaccine has the advantage of using a combination of four different strains of Ebola, producing the item more likely to be effective in different epidemic outbreaks compared to the Merck vaccine, which is usually based on just one strain.
Both vaccines need to be stored in sub-freezing temperatures to last more than six months, a significant hurdle in places like eastern Congo where electricity is usually absent or unreliable.
Additional reporting by Vittoria Elliott in brand-new York.