As new coronavirus variants sweep across the world, scientists are racing to understand how dangerous they could be. WSJ explains. Illustration: Alex Kuzoian/WSJ
How does each of the available Covid-19 vaccines work?
Once the vaccine is injected, the mRNA is taken up by the macrophages near the injection site and instructs those cells to make the spike protein. The spike protein then appears on the surface of the macrophages, inducing an immune response that mimics the way we fight off infections and protects us from natural infection with SARS-CoV-2. Enzymes in the body then degrade and dispose of the mRNA. No live virus is involved, and no genetic material enters the nucleus of the cells.
Although these are the first mRNA vaccines to be broadly tested and used in clinical practice, scientists have been working on mRNA vaccines for years. And despite this wonderful parody piece. opens in new tab saying that the technology is “obvious,” in fact the breakthrough insight that put the mRNA inside a lipid coating to prevent it from degrading is quite brilliant — and yes, this may be the first time the New England Journal of Medicine has referenced a piece in The Onion. (Last reviewed/updated on 11 Jan 2021)
How should early side effects be managed?
Analgesics and antipyretics such as acetaminophen or ibuprofen are effective in managing post-vaccine side effects including injection-site pain, myalgias, and fever. However, the CDC does not recommend prevaccine administration of these drugs, as they could theoretically blunt vaccine-induced antibody responses.
Because of the small risk of anaphylaxis, sites that administer the vaccines must have on hand strategies to evaluate and treat these potentially life-threatening reactions. The CDC has issued recommendations on how sites should prepare. opens in new tab. (Last reviewed/updated on 11 Jan 2021)
How long will the vaccines work? Are booster doses required?
Since the vaccines have been tested only since the summer of 2020, we do not have information about the durability of protection. Data from the phase 1 trial of the Moderna vaccine suggested that neutralizing antibodies persisted for nearly 4 months. opens in new tab, with titers declining slightly over time. Given the absence of information on how long the vaccines will be protective, there is currently no specific recommendation for booster doses. (Last reviewed/updated on 11 Jan 2021)
Do the vaccines prevent transmission of the virus to others?
Many commentaries on the results of the vaccine clinical trials cite a lack of information on asymptomatic infection as a limitation in our knowledge about the vaccines’ effectiveness. Indeed, this is a theoretical concern, since up to 40% of people who get infected with SARS-CoV-2 have no symptoms but may still transmit the virus to others.
Nonetheless, there are several good reasons to be optimistic about the vaccines’ effect on disease transmission. First, in the Moderna trial. opens in new tab, participants underwent nasopharyngeal swab PCR testing at baseline and testing at week 4, when they returned for their second dose. Among those who were negative at baseline and without symptoms, 39 (0.3%) in the placebo group and 15 (0.1%) in the mRNA-1273 group had nasopharyngeal swabs that were positive for SARS-CoV-2 by RT-PCR. These data suggest that even after one dose, the vaccine has a protective effect in preventing asymptomatic infection.
Second, findings from population-based studies now suggest that people without symptoms are less likely to transmit the virus to others. Third, it would be highly unlikely in biological terms for a vaccine to prevent disease and not also prevent infection. If there is an example of a vaccine in widespread clinical use that has this selective effect — prevents disease but not infection — I can’t think of one!
Until we know more, however, we should continue to emphasize to our patients that vaccination does not allow us to stop other important measures to prevent the spread of Covid-19. We need to continue social distancing, masking, avoiding crowded indoor settings, and regular hand washing. (Last reviewed/updated on 11 Jan 2021)
Over the course of the pandemic, scientists have been monitoring emerging genetic changes to Sars-Cov-2. Mutations occur naturally as the virus replicates but if they confer an advantage – like being more transmissible – that variant of the virus may go on to proliferate.
This was the case with the ‘UK’ or B117 variant, which is about 50% more contagious and is rapidly spreading around the country. So how does genetic surveillance of the virus work? And what do we know about the new variants? Ian Sample speaks to Dr Jeffrey Barrett, the director of the Covid-19 genomics initiative at the Wellcome Sanger Institute, to find out Coronavirus – latest updates See all our coronavirus coverage.
Virologist Angela Rasmussen talks about her battle against misinformation in the media, the virus, vaccines, disinfecting surfaces, home testing, and the next pandemic.
Eric J. Topol, MD: Hello, I’m Eric Topol for Medscape, and this is Medicine and the Machine. I’m so glad to have my colleague and partner in this podcast, Abraham Verghese, with me from Stanford. Today, we have the rarefied privilege to discuss the whole pandemic story, the virus and vaccines, with one of the country’s leading virologists, Dr Angela Rasmussen. Welcome, Angie.
Angela L. Rasmussen, MA, MPhil, PhD: Thank you so much for having me, Eric. It’s wonderful to be here.
We enter 2021 surrounded by these rays of hope that the end of the pandemic might be in sight. But monumental challenges remain. Vaccine manufacture, distribution, and uptake are substantial pieces of a complex puzzle that must be completed to reach the 75–90 percent vaccination rate that global health experts say is key to stopping the spread.
And the virus itself is almost sure to change as it infects more people, possibly becoming more transmissible or dangerous. For instance, as I write this in late December 2020, public health officials in the UK are reporting the rapid spread of a new strain of SARS-CoV-2 that seems to be highly infectious.
This is a perfect example of the continued surprises this pandemic may yet throw at us. But virologists, epidemiologists, drug developers, and other scientists will continue to band together to study this virus and share information that can help humanity address this and future issues appropriately. In addition to careful monitoring of the virus as it mutates and spreads, I fully expect there to be regular monitoring of vaccinated individuals, further refinement of vaccine, and continued development of new COVID-19 therapies. And I can promise that The Scientist will continue to track these developments closely and provide up to date and accurate information about the COVID-19 pandemic and other scientific issues in 2021 and beyond.
New research could help explain why thousands of Covid-19 survivors are facing debilitating neurological symptoms months after initially getting sick. WSJ breaks down the science behind how the coronavirus affects the brain, and what this could mean for long-haul patients. Illustration: Nick Collingwood/WSJ
In 2020, the study of the SARS-CoV-2 virus was undoubtedly the most urgent priority. But there were also some major breakthroughs in other areas. We’d like to take a moment to recognize them.
- 1. This year, we learned that we had severely underestimated the human brain’s computing power. Researchers are coming to understand that even the dendritic arms of neurons seem capable of processing information, which means that every neuron might be more like a small computer by itself.
- 2. The new Information Theory of Individuality completely reimagines the way biologists have traditionally thought about individuality. Armed with information theory, the researchers found objective criteria for defining degrees of individuality in organisms.
- 3. Deprived of sleep, we and other animals die within weeks. More than a century of scrutiny failed to explain why lack of sleep is so deadly. This year, an answer was finally found — not inside the brain, as expected, but inside the gut.
OraSure Technologies has blazed a trail in at-home diagnostic tests. Now, the Pennsylvania-based biotech company is working to produce a quick, over-the-counter coronavirus test that consumers can take in the privacy of their home with results available in minutes. NPR’s Allison Aubrey reports.
Early data from US biotech Moderna has revealed that its Covid-19 vaccine candidate is 94.5 per cent effective, raising hopes that a range of immunisations will be available to help end the pandemic. The interim analysis of the vaccine, currently known as mRNA-1273, comes after 95 trial participants contracted Covid-19, including just five who were given the coronavirus jab. While the data was published via a press release, it includes significant details that remain unclear around the Pfizer-BioNTech vaccine – which uses the same mRNA technology to target the coronavirus spike protein and an immune response.