The cause of the rapid increase is the Omicron variant – and its more contagious sub-variant, BA.2, which has already become dominant in the United States, Europe and many parts of the world.
On Sunday, the ruling Communist Party announced the deployment of thousands of military personnel to the closed city of Shanghai to help with the mandatory screening of the 25 million inhabitants.
Chinese health authorities have repeatedly warned of the risk that health care systems will be overwhelmed if the virus spreads widely among the population of 1.4 billion – especially given the low vaccination rate. in the elderly – as they put in place their radical attempts to stamp infections down.
Meanwhile, in the United States and Europe, leaders are finding ways to circumvent Covid-19 as it tends to become endemic. Senate lawmakers this week agreed to a $10 billion bipartisan Covid aid bill that allows the Biden administration to buy more vaccines, maintain testing capacity and continue research In progress.
The move comes as companies and several states scrap their last remaining rules; a mask requirement on planes and at airports is due to expire this month, and those leading the country’s response seem increasingly reluctant to impose tough new rules in the near future.
“Lockdown for the sake of lockdown doesn’t make sense,” Dr. Anthony Fauci, chief medical adviser to President Joe Biden and director of the National Institute of Allergy and Infectious Diseases, told CNN last week.
In England, the few remaining Covid-19 measures ended last week, with Prime Minister Boris Johnson encouraging Britons to be “careful and considerate” if they test positive but no longer asking them to self-isolate.
So which approach is the most appropriate? It’s not a simple answer, experts say.
“Public health is really a local thing,” Andy Pekosz, a virologist at the Johns Hopkins School of Public Health, told CNN, with immunity rates dramatically different from country to country.
It also means the spike in cases in China won’t necessarily happen elsewhere.
“I expect to see a resurgence (in the United States), but it’s a very different picture, even with the increase in the Omicron BA.2 subvariant,” added Gillings epidemiologist Justin Lessler. School of Global Public at the University of North Carolina. Health.
Lessler said that, given the level of immunity in the population, a “mild hit” is more likely in the United States than the dramatic spike seen in China.
YOU ASKED. WE ANSWERED.
Q: Do I need a second booster shot?
A: Last week, the US Food and Drug Administration (FDA) authorized a second Covid-19 booster for certain people – adults over 50 and some immunocompromised people 12 and older.
Getting a fourth dose of the vaccine isn’t “something everyone needs to get right now,” said Dr. Leana Wen, CNN medical analyst and emergency physician.
“We know that vaccination, plus that first booster, still protects you very well, including against serious illnesses,” she said. But “some people may want an extra level of protection; if you’re over 65, have chronic conditions, and are over 50, you might want that fourth dose.”
Wen stressed that “everyone who is eligible” should receive the first booster, noting that many have yet to do so. Then, four or more months after that dose, when you become eligible for another, you can determine if you would benefit from the additional booster.
READINGS OF THE WEEK
The first study on the human challenge of Covid-19 gives valuable insights into how we get sick
It only takes a tiny virus-laden droplet – the width of a human blood cell – to infect someone with Covid-19.
This was shown in a study that deliberately infected healthy volunteers with the SARS-CoV-2 virus. The results of this research were published March 31 in the journal Nature Medicine.
But they are also extremely valuable in understanding the course of an infection.
“Really, there’s no other type of study where you can do that, because normally patients only come to your attention if they’ve developed symptoms, and so you miss all those previous days where infection is brewing,” said the study’s lead author. Dr Christopher Chiu, infectious disease physician and immunologist at Imperial College London.
There is no ‘magic moment’ to lift Covid-19 restrictions, researchers say
Pandemic hospitalization rates are at new lows in the United States, with all 50 states lifting mask requirements starting March 25. But is there a cost to lifting restrictions and trying to return to a pre-pandemic normal?
In a new study, researchers predict that the lifting of masking and social distancing restrictions in March 2022 could lead to a resurgence in Covid-19 deaths in most states, based on projections from a simulation model.
The researchers simulated the lifting of restrictions at different times of the year and predicted the number of deaths that would follow using current estimates of infection and vaccination rates, while taking into account differences in risk between groups of people. ‘age.
“There is probably no additional wait time in any state, after which withdrawal [Covid-19 restrictions] will not lead to increased morbidity and mortality,” the study states.
How the next variant could emerge
The origin of Omicron remains a mystery: how did a variant that seemed so different from all of its older cousins arise so suddenly? How to explain its jumble of mutations, many of which had rarely been seen in variants of interest?
In a March briefing, Dr Mike Ryan, executive director of the World Health Organization’s Health Emergencies Programme, said: “As the virus replicates, there are errors in the reproduction of its code.”
Viruses change all the time, often in ways that affect their chances of survival. But once in a while, these mutations can work in favor of the virus.
Should we continue to wear a mask on flights?
The rule requiring masks on planes, airports and other public transportation is due to expire in the United States this month.
Experts are divided on whether this is a good idea. Linsey Marr, an expert on aerosol infectious disease transmission, told CNN last week that dropping the mask mandate is reasonable with the caveat that it makes sense “as long as cases stay low.”
But you can decide to continue to cover yourself when traveling – and the time you spend in the air is worth considering.
“I think I will definitely continue to use a mask for my own protection, especially if I’m going long distances,” said London-based travel health specialist Dr Richard Dawood.
THE PODCAST OF THE DAY