Factual and reliable information is vital to creating trust in vaccines and to overcoming the pandemic. Ed Carr, The Economist’s deputy editor, and Natasha Loder, our health policy editor, answer some of the big questions about the global vaccination drive.
Chapters 00:00 – Challenges in vaccinating the world 00:45 – Trust in vaccines 02:30 – mRNA vaccines 03:23 – Impact of variants on vaccination 04:29 – Time between vaccine doses 06:09 – Mandatory vaccines for travel?
As countries like the United States and United Kingdom inoculate their residents with never-before used vaccine technology, others, including Russia, China, and India, are investing in more traditional approaches, like inactivated coronavirus vaccines. But no matter the technique, together they have the potential to create multiple lines of defense against SARS-CoV-2. Science senior correspondent Jon Cohen explains how each of these vaccines can protect us from severe illness—and what understanding the details of our immune responses could mean for the future of human trials.
The unfortunate reality is that COVID-19 might not be the last pandemic. The threat of the next pandemic will always be hanging over our heads—unless the world takes steps to prevent it. You can learn more about this topic in our 2021 Annual Letter at http://gatesnot.es/3a5KOLU
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)
Messenger RNA—or mRNA—vaccines have been in development for decades, and are now approved for use against COVID-19. Here’s how they work and what you should know about them. Visit https://www.jhsph.edu/covid-19 for even more resources.
Vaccines are one of the most effective tools we have in preventing and reducing the burden of infectious diseases. In the midst of the COVID-19 pandemic, vaccines are once again poised to change the tide in our favor in the fight against a deadly virus. But how exactly do vaccines work? And are they safe? “You can think of your body’s immune system like an orchestra,” says Yale immunobiologist Akiko Iwasaki, PhD. “The different functions of the immune response are like different instruments. And vaccines work like sheet music for the orchestra, telling the immune system what to do and how to do it.” Different viruses require different types of immune responses in order to confer protection, and some of them can be complex. But with SARS-CoV-2, the virus that causes COVID-19, a simple type of response is all that’s needed to prevent infection. “You just need to trigger an antibody response where the antibodies bind to the surface of the virus and prevent it from entering our cells,” says Ruslan Medzhitov, PhD, professor of immunobiology. “And these types of vaccines tend to be extremely safe.” In addition to the inherent safety of this kind of “training” for the immune system, experts emphasize that the expedited timeline of COVID-19 vaccine development is not a reflection of lax safety standards. “Before a vaccine is approved, it goes through a rigorous amount of testing for safety and efficacy,” says Iwasaki. “So, once a vaccine is made to be publicly available, we should be lining up.” Watch this video to learn more about the fundamentals of how vaccines work, how they are developed, and the importance of vaccination for public health.
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.
Boomers Daily 