Xi Jinping reiterated China’s commitment to zero-COVID, declaring “persistence is victory”, as Shanghai and Beijing were hit with new lockdowns, shutdowns, and mass testing drives just a week after the cities celebrated the easing of restrictions. (www.theguardian.com/world/2022/jun/10/xi-jinping-says-persistence-is-victory-as-covid-restrictions-return-to-shanghai-and-beijing)
In response to China’s worst outbreak of the pandemic, Shanghai spent months under an arduous and strict citywide lockdown, while Beijing authorities imposed localised lockdowns, venue and public transport shutdowns, and work-from-home orders. In the last week both had begun easing restrictions, with authorities praising the containment of the community outbreaks of the Omicron variant.
But last Thursday both cities went back on high alert for Covid cases, with new lockdowns in Shanghai districts, home to millions of people, and the shutdown of entertainment venues in Beijing’s populous Chaoyang district. The return to restrictions sparked alarm and frustration among residents.
Experts predict that China will struggle to meet its economic growth target of about 5.5% this year as virus lockdowns force business shutdowns and snarl supply chains.
Half of Shanghai’s residents, about 14 million people, were this week ordered to undergo testing. All residents of the affected districts have been ordered to stay inside until it is completed.
Officials on Thursday traced three Shanghai infections to the Red Rose, a popular beauty salon in the trendy former French Concession area of the Xuhui district. The shop, which reopened in 1 June when the city did, had served 502 customers from 15 of Shanghai’s 16 districts in the past eight days, a local media outlet, The Paper, reported.
China reported 73 new local infections on Friday, including eight in Beijing and 11 in Shanghai, according to the National Health Commission.
A team of international scientists tasked with understanding how the coronavirus pandemic began released their first report on Thursday, saying that all hypothesis remain on the table, including a possible laboratory incident. https://edition.cnn.com/2022/06/10/china/who-covid-pandemic-origins-report-intl-hnk/index.html?
The 27-member scientific advisory group convened by the World Health Organization (WHO) said available data suggests the virus jumped from animals to humans but gaps in “key pieces of data” meant a complete understanding of the pandemic’s origins could not be established.
The team, called the Scientific Advisory Group for the Origins of Novel Pathogens (SAGO), was formed last year to recommend further areas of study to better understand the pandemic’s origins and as well as the emergence of future pathogens.
Here are key takeaways from the report.
Current data suggests a zoonotic origin of SARS-CoV-2 — which means the virus originated in animals and jumped to humans.
The most closely genetically related viruses were found to be beta coronaviruses identified in bats in China and Laos, according to SAGO.
“However, so far neither the virus progenitors nor the natural/intermediate hosts or spill-over event to humans have been identified,” the report said.
The seafood market
Another area the group identified for further study is the Huanan Seafood Market in Wuhan, which investigations suggest “played an important role early in the amplification of the pandemic.”
However, it is not clear how the source of the virus was introduced to the market and where the initial spill over to humans occurred, the group said, adding that follow-up studies have not been completed.
The lab-leak theory
SAGO’s preliminary report said it “remains important to consider all reasonable scientific data” to evaluate the possibility that COVID-19 spilled into the human population through a laboratory incident.
However, the group said there “has not been any new data made available” to evaluate this theory and recommended further investigation “into this and all other possible pathways.”
The team also had access to unpublished blood samples from 40,000 donors in Wuhan between September and December 2019, and reported to have been tested for COVID antibodies. Their samples could contain crucial signs of the first antibodies made by humans against the disease.
According to the report, more than 200 samples initially tested positive for the antibodies but when tested again were not found to be positive.
Similarly, the group recommended further study of 76,000 COVID patients identified in the months before the initial outbreak in Wuhan in December 2019 and who were later discounted.
On Thursday, WHO Director-General Tedros said it has been two-and-a-half years since Covid-19 was first identified but “we do not yet have the answers as to where it came from or how it entered the human population.”
The United States Food and Drug Administration’s (FDA’s) vaccine advisory panel this week recommended nearly unanimously that the agency authorize a protein-based COVID-19 vaccine from Novavax, which would be the first of its kind available to U.S. adults. FDA doesn’t have to abide by its advisers’ recommendations but usually does. In a 30,000-person trial in the US and Mexico, the vaccine was 90.4% efficacious at preventing symptomatic infection by early strains of SARS-CoV-2. www.science.org/content/article/news-glance-african-swine-fever-vaccine-low-dose-radiation-and-bees-fish?
Eleven days after being bitten by one of her pet prairie dogs, a 3-year-old girl in Wisconsin on 24 May 2003 became the first person outside of Africa to be diagnosed with monkeypox. Two months later, her parents and 69 other people in the United States had suspected or confirmed cases of this disease. which is caused by a relative of the much deadlier smallpox virus. The monkeypox virus is endemic in parts of Africa, and rodents imported from Ghana had apparently infected captive prairie dogs, North American animals, when an animal distributor in Texas housed them together. (www.science.org/content/article/concern-grows-human-monkeypox-outbreak-will-establish-virus-animals-outside-africa?)
The outbreak now underway has affected more people outside of Africa than ever before—nearly 1300 cases as of 7 June, on multiple continents. But like the 2003 episode, today’s surge has raised a possibility that makes researchers gulp: Monkeypox virus could take up permanent residence in wildlife outside of Africa, forming a reservoir that could lead to repeated human outbreaks.
No animal reservoir currently exists outside of Africa, but the US outbreak of 2003 was a close call, some scientists suspect, especially because nearly 300 of the animals from Ghana and the exposed prairie dogs were never found. In the end, however, surveys of wild animals in Wisconsin and Illinois never found monkeypox virus, none of the infected humans passed on the disease to other people, and worries about this exotic outbreak evaporated.
Will North and South America, Europe, Asia, and Australia—all of which have reported monkeypox cases in this outbreak—be similarly fortunate this time?
Viruses frequently ping-pong between humans and other species. Although COVID-19 is widely thought to have resulted from SARS-CoV-2 jumping from a bat or other host into people, humans have, in “reverse zoonoses,” also infected white-tailed deer, minks, cats, and dogs with the virus. One study in Ohio found antibodies to SARS-CoV-2 in more than one-third of 360 wild deer sampled.
Public health officials in several countries have advised people who have monkeypox lesions to avoid contact with their pets until they heal. Some 80% of the cases have occurred in Europe, and the European Food Safety Authority said no pets or wild animals had been infected as of 24 May. But it added that “close collaboration between human and veterinary public health authorities is needed to manage exposed pets and prevent the disease from being transmitted to wildlife.”
Studies have yet to pinpoint the African reservoir of the monkeypox virus. Although a lab in Copenhagen, Denmark, in 1958 first identified it in research monkeys from Asia, scientists now believe the primates caught it from an African source. All human cases since the first one was reported in 1970, in the Democratic Republic of Congo (DRC which was then Zaire), could be tied to the virus spilling over from animals in Africa.
In 1959, German microbiologist Anton Mayr took a strain of vaccinia, a poxvirus used to inoculate against smallpox, and started to grow it in cells taken from chicken embryos. After several years of transferring the strain to fresh cells every few days, the virus had changed so much it could no longer reproduce in most cells from mammals. But it could still produce an immune response that protected against smallpox.
Mayr had set out to study how poxviruses evolve, but by accident he had produced a potentially safer smallpox vaccine. Dubbed Modified Vaccinia Ankara (MVA) because the original viral strain came from that Turkish city, the vaccine had a short career. “With smallpox eradicated in 1980, it disappeared into the freezer,” says Gerd Sutter, a virologist at the Ludwig Maximilian University of Munich, who has studied Mayr’s vaccinia strain for decades.
Now, this virus, further weakened and brought to the market by the Danish pharma company Bavarian Nordic, may become key to arresting the largest outbreak of monkeypox ever seen outside Africa, which has already sickened more than 1000 people. It is the only vaccine licensed anywhere for use against monkeypox, although other, riskier smallpox vaccines also appear to offer some protection.
But what role the vaccine will ultimately play depends on a host of factors: whether those most at risk from infection can be identified and vaccinated, whether the vaccine is as effective as hoped, and whether enough is available to stop the burgeoning outbreak.
Hundreds of millions of doses of smallpox vaccine are stored around the world, insurance against a possible release of the dreaded virus by terrorists or in war, and they are known to offer some protection against monkeypox. A study in the DRC in the 1980s found that household contacts of people sick with monkeypox were seven times less likely to contract the disease if they had been vaccinated against smallpox. Yet the vast majority of existing smallpox vaccines consist still replicating vaccinia. These can cause rare but life-threatening side effects such as encephalitis or progressive vaccinia, the spread of the vaccine virus to the whole body, to which immunocompromised people are vulnerable.
Although 66 people have already died of monkeypox this year in African countries, the recent cases in nonendemic countries have mostly been mild. And many contacts of those infected are living with HIV, which could make them more likely to suffer from vaccinia side effects. Given the risks and benefits, “using these vaccines is out of the question,” Sutter says.
Bavarian Nordic’s nonreplicating vaccine, marketed as Jynneos in the United States and as Imvanex in Europe, sidesteps some of the risk. So does a vaccinia-based vaccine named LC16m8, licensed for smallpox only in Japan, which also appears to cause fewer side effects.
WHO’s Strategic Advisory Group of Experts on Immunization is set to release guidance in the next few days that will back MVA, but it will also recommend using earlier vaccines in certain scenarios.
How well MVA really protects humans from monkeypox is uncertain. The license for MVA in Canada and the US is based on animal studies, where it was shown to protect macaques and prairie dogs, plus data in humans showing a strong antibody response.
That is why WHO has urged countries that deploy monkeypox vaccine to study how well it works and how best to use it. One question is whether a single dose of the vaccine, which is normally given as two doses 4 weeks apart, may suffice. That could encourage more uptake and stretch supplies.
Lalita Panicker is Consulting Editor, Views and Editor, Insight, Hindustan Times, New Delhi