Via The Lancet: Too many unknowns stymie response to MERS. Excerpt:
The first known serious coronavirus epidemic—severe acute respiratory syndrome (SARS)—broke out in 2002 and caused 8275 cases and 775 deaths in 14 countries.
The latest epidemic, Middle East respiratory syndrome (MERS), so named for its first appearance in the Arabian Peninsula, in 2012, has, as of June 26, caused 1350 cases in 26 countries and at least 480 deaths. Most cases and deaths have occurred in Saudi Arabia. At the end of May, to the surprise of the international health community, 162 cases and 19 deaths occurred, not in the Middle East, but in South Korea.
Current epidemiological evidence points to dromedary (Arabian one-humped) camels as the main reservoir of the coronavirus causing the Middle-East cases. (The source of the SARS coronavirus is not known for sure but is believed to be bats.) Most of the South Korean cases are thought to have been caused by a coronavirus originally imported from the Middle East by travellers and subsequently transmitted in hospitals from infected patients to family visitors and hospital staff.
“The reality of the world today is high levels of travel and inter-connectedness, so it should be no surprise to see any infection appearing anywhere”, says Keiji Fukuda, WHO's Assistant Director-General for Health Security.
“But when I visited South Korea in June”, he tells The Lancet, “it was clear that the health workers there had at first thought of MERS as if it was on the other side of the world, as if it couldn't happen there.”
So far there is no evidence that person-to-person transmission is occurring in the MERS outbreak to a great extent. Close contact between people seems to be required.
“All three infections, Ebola, SARS, and now MERS”, Fukuda says, “deeply underscore the fact that we don't have our infection prevention and control practices at anywhere near the right level and it also underscores the difficulty of getting them to the right level.”
In the view of Laurie Garrett, senior fellow for global health at the Council on Foreign Relations, New York, NY, USA, getting preventive measures “to the right level” would, as a first step, require WHO's International Health Regulations Emergency Committee to declare MERS a “Public Health Emergency of International Concern”, as it did for the Ebola epidemic.
Speaking to The Lancet, she comments: “Since the first MERS case appeared in July, 2013, the committee has met nine times and has refused to make that declaration. One reason given was the possible impact on Saudi Arabia's economy. Another was fear of panicking pilgrims to the Hajj. A third, given at the committee's latest meeting in June, was insufficient knowledge about the transmission of the virus.
"These reasons don't take into account the reality that Saudi Arabia is still being plagued by major nosocomial outbreaks amounting so far to more than 1000 cases and more than 400 deaths. If that committee doesn't act soon, we're going to be living with this virus for a very long time.”
There certainly is, as the committee pointed out, a lack of knowledge about the virus. “We know that dromedary camels are reservoirs of the MERS coronavirus but we don't know if there are other animals harbouring the virus”, says Fukuda. “We don't know how the virus is transmitted and we still don't understand the full spectrum of illness and pathology of the virus.”
To accelerate progress in resolving these unknowns, WHO has convened scientists and public health officials from the affected countries to four meetings in Cairo, Egypt, and plans to hold another in the next 6 months.
Meanwhile, research is underway. Drugs already on the market, such as ribavirin and interferon alpha 2a, are being “repurposed” for potential treatment of MERS and are seemingly being used already for patients in Saudi Arabia. A phase 2 clinical trial of serum containing antibodies from MERS survivors is planned in Jeddah, Saudi Arabia. Particularly promising results have been obtained by US researchers studying MERS treatment with antibodies from cattle engineered to carry human immunoglobulin genes.
As for vaccines, about a dozen are in the pipelines of at least six drug companies and as many research groups in at least six countries, but no candidate has yet gone past the in-vitro stage. Work is also planned to develop a vaccine that would protect camels from the coronavirus.