Corona Letter: Psychological distress is a big risk factor for long Covid

When we started this newsletter on March 20, 2020, there was more panic over Covid-19 than information about the virus and how it spreads.

As the crisis unfolded over the next couple of months, the role of reliable information became even more crucial. We decoded the virus, its variants, vaccines, symptoms, new research and more, and your feedback and suggestions helped us get better at it every day.

While the virus is still floating around, most of us are fully vaccinated and more aware of the virus and what to expect. As the pandemic eases, we have decided to take a break too. This is the last edition of The Corona Letter in your mailbox.

Thank you for being a part of our journey.

The Corona Letter Team

P.S. For all things health, you can subscribe to our weekly Health+ newsletter here.

• India on Sunday reported 176 Covid cases and 5 fatalities. The cumulative caseload is 4.46 crore (3,552 active cases) and 5.3 lakh fatalities
• Worldwide: Over 652 million cases and over 6.6 million fatalities
• Vaccination in India: Over 2.2 billion doses. Worldwide: Over 13.1 billion doses

• What: China’s abrupt lifting of stringent Covid-19 restrictions could result in an explosion of cases and over a million deaths through 2023, according to new projections from the US-based Institute of Health Metrics and Evaluation (IHME).
• How: According to the group’s projections, cases in China would peak around April 1, when deaths would reach 322,000. About a third of China’s population will have been infected by then, IHME Director Christopher Murray said.
• But… China’s national health authority has not reported any official Covid deaths since the lifting of restrictions. The last official deaths were reported on Dec. 3. Total pandemic fatalities stand at 5,235.
• Fears of a spike: China lifted some of the world’s toughest Covid restrictions in December after unprecedented public protests and is now experiencing a spike in infections, with fears Covid could sweep across its 1.4 billion population during next month’s Lunar New Year holiday.
• New projections: The independent modelling group at the University of Washington in Seattle, which has been relied on by governments and companies throughout the pandemic, drew on provincial data and information from a recent Omicron outbreak in Hong Kong. “China has since the original Wuhan outbreak barely reported any deaths. That is why we looked to Hong Kong to get an idea of the infection fatality rate,” Murray said.
• The method: For its forecasts, IHME also uses information on vaccination rates provided by the Chinese government as well as assumptions on how various provinces will respond as infection rates increase.
• Other models: Disease modellers at the University of Hong Kong predict that lifting Covid restrictions and simultaneously reopening all provinces in December 2022 through January 2023 would result in 684 deaths per million people during that timeframe, according to a paper released on Wednesday on the Medrxiv preprint server that has yet to undergo peer review. Based on China’s population of 1.41 billion, and without measures such as a mass vaccination booster campaign, that amounts to 964,400 deaths.
• Another study published July 2022 in Nature Medicine by researchers at the School of Public Health at Fudan University in Shanghai predicted an Omicron wave absent restrictions would result in 1.55 million deaths over a six month period, and peak demand for intensive care units of 15.6 times higher than existing capacity.
• Vaccination: China’s National Health Commission said on Friday it was ramping up vaccinations and building stocks of ventilators and essential drugs.

• An intermediate level of anticoagulation (blood thinning) had an 86% probability of being more helpful than low or high dose anticoagulation in Covid-19 patients, according to a new study. Covid-19 patients in hospitals are at increased risk of blood clots (or thromboses), which in turn may contribute to development of organ failure.

Significance

• Anticoagulant use was recommended in all Covid-19 treatment guidelines, including in India, but the most effective and safest dose is not known yet. This trial was done to find out the dose that provided the most benefit at the lowest risk.

The study

• The study was based on a randomised clinical trial to test different levels of anticoagulation in more than 1,500 patients in India, Australia, New Zealand and Nepal. The AustralaSian Covid-19 Trial (ASCOT) has pinpointed the most efficient level of blood thinning treatment for Covid-19 patients in the study published in the ‘New England Journal of Medicine Evidence’. The research was presented at the American Society for Hematology conference.
• “Many treatment guidelines recommend the use of low doses but are less certain in their recommendations about higher doses for the treatment of hospitalised non–critically ill adults with Covid-19 and recommend that more studies be done to establish their safety and efficacy,” said Vivekanand Jha, executive director of George Institute for Global Health India.

Findings

• The findings show that an intermediate level of anticoagulation had an 86% probability of being better than low-dose anticoagulation. A higher therapeutic dose did not show any benefit. This finding will likely lead to changes in treatment guidelines with regard to optimal dosing.

• A mucosal DNA vaccine can effectively halt Covid-19 in its tracks, a study on mice by an international research team has revealed.

What’s mucosal vaccine

• Mucosal vaccination through the mucous membranes, which is less widely known, may offer effective protection against SARS-CoV-2 infections, according to the study. It is believed that immune cells in the nose and lungs are better equipped to recognise and neutralise the virus that causes Covid-19.

How it works

• This vaccine functions similarly to commercially available RNA vaccines, made using a vector created by a Centre National de la Recherche Scientifique (CNRS) researcher at the Immunology and New Concepts in Immunotherapy Laboratory, Nantes University, France.
• The vector’s DNA enters the target cells, triggering the production of the SARS-CoV-2 protein and triggering the immune system to produce antibodies and lymphocytes to fight the virus.
• A vector is a component used in medicinal chemistry to deliver a molecule to a specific area of the body. The vector in this instance is a synthetic nano-particle, whose characteristics enable it to pass through mucous membranes and introduce DNA encoding a viral protein into respiratory system cells.

Study on mice

• The research has shown that, in contrast to the virus, which kills 100% of unvaccinated mice, its mucosal DNA vaccine can guarantee the complete survival of a group of mice infected with the variant that has been adapted to this species. Ten mice were tested in each group, reported news agency PTI.
• However, the effectiveness of the vaccine in preventing mouse-to-mouse transmission was not assessed in the study – titled ‘Respiratory mucosal vaccination of peptide-poloxamine-DNA nanoparticles provides complete protection against lethal SARS-CoV-2 challenge’, which has been published in the Biomaterials journal.
• But researchers are hopeful that an approach to vaccination based on this idea will be able to improve upon the current plan by, among other things, offering better protection against transmission, reported PTI.