Remembering Ebola: two years on
Two years after the end of the West African Ebola epidemic, are we prepared for another outbreak?
Locals celebrating in the streets of Liberia after the country was declared free of EbolaEPA/Ahmed Jallanzo
by
Shoomena Anil
Saturday December 23 2017, 12:02pm
Nearly two years ago, the World Health Organisation (WHO) declared the end of the 2014 Ebola epidemic in West Africa. By then, the virus had infected 50 times more people than any previous Ebola outbreak.
Apocalypse averted, in other words.
Nonetheless, more than 11,000 people were killed before arguably outdated methods, such as isolating cases and quarantining the contacts of those diagnosed, put an end to the outbreak. Overall, inadequate health facilities, sub-standard infection control and a slow international response contributed to the most widespread outbreak of Ebola in history. The fact that in 2017 the word barely passes our lips begs the question: where do we currently stand in the war against of Ebola?
“What is the likelihood of a future Ebola outbreak? High, actually”
In the wake of the 2014 epidemic, a pharmaceutical marathon has ensued.
Scientists in Russia and China have already licensed vaccines. Most recently, a vaccine touted as 100% effective, rVSV-ZEBOV, has been placed under review for use by the FDA in the USA. The genetic ‘spine’ of this vaccine is that of the vesicular stomatitis virus, which infects cattle but not humans. Spliced into the spine is the gene coding for the membrane protein of the Zaire strain of the Ebola virus that prompts the immune system to make antibodies against the pathogen, without the virus taking hold. It is suggested that in the event of another Ebola outbreak, the world might be able to turn to an emergency supply of this vaccine, currently available in a bank of 300,000 doses.
Yet, what is the likelihood of a future Ebola outbreak? High, actually. The virus is under evolutionary pressure to infect humans more readily. The A82V mutation, which alters the protein used by the virus to enter host cells, arose early in the 2014 epidemic and coincided with its acceleration. This makes sense, since studies show that the A82V mutation allows the Ebola virus to infect humans up to four times more efficiently than the ‘original’ strain.
The Ebola virus particle. The disease will likely continue to mutate, with potentially catastrophic consequencesCenter for Disease Control, USA
A further exacerbating factor is urbanisation, which also contributed to the unleashing of HIV. According to the African Development Bank, the continent has had the world’s highest urban growth rate for 20 years, and the proportion of Africans living in cities will rise from 36% today to 60% by 2050. When it comes to infectious diseases, living in such close quarters can lead to disaster.
“Evidently, this is not only West Africa’s problem”
Alongside advances in vaccination, there are other ways in which we can prepare for a further Ebola outbreak. Pivotally, West Africa must strengthen its health infrastructure, in particular, with respect to hospital infection control and educating the public. Furthermore, surveillance could prove key to limiting future outbreaks. The 2014 Ebola crisis mobilised unprecedented financial assistance for West Africa: $400 million from the World Bank was directed towards an ambitious blueprint that revolves around the concept of public health surveillance. Each country in West Africa is to share surveillance data systematically, with a regional hub via a national coordinating institute. While this is planned to be fully staffed by early 2018, at the last report just 9 of the 15 countries had designated their national coordinating institute. It is crucial that a move is taken from words into action, so that future cases may be able to be detected and dealt with more quickly, and tragedy averted.
Evidently, this is not only West Africa’s problem. As an international community, we need to unite behind the broader aims of improving living conditions and sanitation, stabilising healthcare facilities, and promoting education if we are to curb future epidemics.
https://www.varsity.co.uk/science/14321
China approves domestic Ebola vaccine developed from recent outbreak
by
Angus Liu |
Oct 24, 2017 4:04pm
China has approved a domestically developed Ebola vaccine based on a different virus type from GSK's and Merck's shots. (CanSino)
As promising Ebola vaccines from global drugmakers GlaxoSmithKline and Merck & Co. still await official licenses, China has approved its own shot, co-developed by the Chinese Academy of Military Medical Sciences’ Bioengineering Institute and domestic vaccine specialist Tianjin CanSino Biologics.
Dubbed Ad5-EBOV, the recombinant adenovirus vector-based vaccine is the first shot based on the strain behind the recent epidemic in West Africa in 2014—the deadliest outbreak in recorded history. Along with the CFDA decision, the Chinese vaccinemaker
revealed (Chinese) a 65,000-square-meter (700,000-square-foot), 70-million-dose-capacity manufacturing site, which the company said is in compliance with the World Health Organization’s cGMP requirement.
The vaccine differs from programs at GSK and Merck because those companies' vaccines are developed to express the glycoprotein of the Ebola virus identified during the disease’s discovery back in 1976. CanSino says the two virus types are very similar, but slight differences could allow its shot to provide better protection in the real world.
RELATED: Ebola vaccines from GlaxoSmithKline, Merck elicit yearlong response, study finds
Because the Ebola crisis has died down, China’s FDA approved Ad5-EBOV without a phase 3 test after putting the product on its expedited review list in April. CanSino told FiercePharma that the vaccine has also been through a challenge experiment at the microbiology lab at the Public Health Agency of Canada, the original developer of Merck's rVSV-ZEBOV.
In a 500-participant phase 2 trial in Sierra Leone, the results of which were
published earlier this year in The Lancet, the vaccine elicited strong antibody responses in volunteers within 28 days. Researchers noted that the responses, though still existent, decreased significantly at day 168, a finding the team said is consistent with previous tests on rVSV-ZEBOV in Africa and Europe.
In a related commentary
published alongside the Ad5-EBOV study results, two experts from the Netherlands expressed concerns about the “durability of protection when implementing mass vaccination campaigns in future outbreak settings in Africa.” CanSino, in a written response to FiercePharma, said the product is positioned for emergency use for now; therefore, it's currently focused on long-term efficacy. The company didn't rule out the possibility for implementing a booster shot in the future.
RELATED: Sinovac to go private as bribery concerns hint at investor class-action lawsuits
A recent phase 2 study conducted by a U.S.-Liberia partnership
showed that responses to Merck’s and GSK’s shots also peaked after a month, and that most recipients of the two shots still had an antibody response at one year.
CanSino's program further incorporates a freeze-drying technique known as lyophilization, which allows the vaccine to be stored at 4°C (39°F) for a long time, and to remain stable at 37°C (99°F) for about three weeks. The other two candidates, on the other hand, must be stored at -70°C (-94°F) or below, and are stable for only one week at 4°C (39°F). This means CanSino's version could be more suitable for the African region in terms of logistics.
https://www.fiercepharma.com/vaccin...d-ebola-vaccine-from-2014-outbreak-virus-type
