Popularization of research advances on COVID-19

2021 - Page 4 of 29 - News

Why is Delta the most contagious variant?

The Wuhan strain of SARS-CoV-2, from which the pandemic originated, has been used to develop currently available vaccines. Since its appearance, several variants have emerged, such as the Alpha (UK), Beta (South African), Gamma (Brazilian) and Delta (Indian). Amongst the molecules that make up SARS-CoV-2, the spike (S) is a key protein. It interacts on […]


Is it more effective to combine different vaccines?

There are a number of different anti-COVID-19 vaccines currently available. Rare but serious side effects have been reported for the AstraZeneca (AZ) vaccine. Several countries have therefore decided to administer the Pfizer-BioNTech (PB) vaccine to people younger than 55 who have already had a 1st dose of AZ. Previous clinical studies have analysed the efficacy […]


COVID lays bare the inequalities of American health provision

The COVID-19 pandemic has led to innovations in terms of political organisation and coordination, but has also revealed weakness in the American health care system. Over the last two years, the system has focused on COVID-19 patients and on the prevention of transmission. But for those patients suffering from chronic illnesses, there have been fewer […]


A vaccine adapted to fight the Beta variant tested on animals

The reasons for the continuation of the pandemic include insufficient vaccination coverage, the weakening of antibody protection over time, and the emergence of variants of concern (VOCs) that are more resistant and that have increased transmissibility. Moderna has recently produced a vaccine (mRNA-1273.β)  “tweaked” to adapt to the Beta (South African) variant, one of the […]


Cases of infection even in vaccinated patients

The Pfizer-BioNTech vaccine has high efficacy against symptomatic COVID-19 infections. However, there have been cases of infection by SARS-CoV-2 in fully vaccinated individuals (2 doses), notably amongst health care staff who in general have greater exposure to the virus. Israeli researchers have looked at these types of cases in order to describe and analyse them, […]


Hybrid immunity is more effective than vaccination alone

The link between a strong neutralising antibody response and protection against infection by the virus has been clearly demonstrated. This is why more than 6 billion doses of the vaccine have been given in an attempt to control the pandemic. But the vaccines have been developed from the spike protein of the original Wuhan strain, […]


A SARS-CoV-2 replicon: a useful system for studying the virus

In order to fight SARS-CoV-2 and equip ourselves with effective therapies, we need to study and test candidate treatments. It is, however, complicated to use the virus in cell culture, mainly for safety reasons. This is a contagious and dangerous virus and it is best to avoid handling it. Researchers at the Universities of Rockefeller […]


The evolution of SARS-CoV-2 in the UK

The COVID-19 pandemic has constantly produced new variants, since SARS-CoV-2 adapts to humans by accumulating around 24 mutations per year. The first dominant mutation was D416G, which rendered this variant 20% more transmissible than the Wuhan ancestral strain. The B.1 lineage thus became established and spread rapidly throughout the world in April-May 2020. Since then, […]


Long-term immune response induced by mRNA vaccines

Attaining herd immunity, whether by infection or by vaccination, is necessary to control the pandemic while SARS-CoV-2 continues to circulate. Different vaccines have been available for several months now, notably the mRNA vaccines. These vaccines encode the spike surface protein of the original Wuhan strain and have been widely administered throughout the world. They are […]


Delaying injection of the second dose makes the vaccine more effective

In December 2020, the UK changed its vaccine administration regime for Pfizer-BioNTech and Astrazeneca by spacing the injections at more than 12 weeks instead of the usual 4. The intention was to accelerate vaccine coverage in the population with a single dose, so as to limit the incidence of severe cases of COVID-19. This policy […]

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