TODAY’S UPDATE ON SARS-COV-2 (3/25/20)
Summary of today’s episode of #twiv. The purpose of this episode was to answer YOUR questions! I encourage you to listen to the whole episode yourself! The link is below. (1/n)
microbe.tv/twiv/twiv-594/
Summary of today’s episode of #twiv. The purpose of this episode was to answer YOUR questions! I encourage you to listen to the whole episode yourself! The link is below. (1/n)
microbe.tv/twiv/twiv-594/
[The TWiV team is doing daily searches on PubMed, bioRxiv, and medRxiv for a regular and comprehensive review of the COVID-19 and SARS-CoV-2 literature]. (2/n)
What’s the deal with antibody tests? Progress is being made on production of antibody tests. The detection of antibodies in your serum could tell you whether you have been infected with SARS-CoV-2 in the past and whether you are now immune. (3/n)
What is convalescent serum? Convalescent serum is serum from patients who have recovered and therefore carry antibodies to the virus. These antibodies can help fight infection in currently infected patients. The FDA approved this treatment for serious infections. (4/n)
Why is there such a high fatality rate in Italy? Among other reasons, testing in Italy was very selective, focusing only on the sickest people. Many others were not tested, they were just sent home to quarantine. (5/n)
This selective testing could explain the high case fatality rate in Italy. If you’re only testing the sickest of the sick, and half the people you test have the virus, you’re missing a whole lot of cases that should be taken into consideration when calculating fatality rates. (6/
How likely can the virus be transmitted through the mail and are postal workers at risk? Transmission of the virus by mail is very unlikely for people receiving mail. (7/n)
It might pose a higher risk for the actual postal workers because they’re immersed in the mail, which has been touched by many people. However, the major route of transmission still occurs by inhaling respiratory droplets, through close contact with other individuals. (8/n)
Transmission through potentially contaminated objects like mail poses a lower risk. However, if you are a postal worker it would be a good idea to wear gloves. (9/n)
Is take-out food safe? Nothing is zero risk. However, you can reduce risk of infection from takeout food by removing the food from the takeout container, disposing of the container, and washing your hands after disposing the container. (10/n)
Is the virus mutating to become more dangerous? No. There is some variation in sequences of circulating viruses, but there is no evidence that some new variant that has “taken over” that is better at transmitting, or causing more serious disease than any others. (11/n)
If I get sick with COVID-19 should I try some of the home remedies that are circulating on the internet? No. Disregard them. Go to a doctor. (12/n)
How do vaccines against viruses work? There are four major types of vaccines: 1) “Killed” vaccines contain inactivated virus that is recognized by your immune system. (13/n)
Your immune system then produces antibodies specific for that virus and is able to recognize that virus should you become infected in the future. (14/n)
2) Live-attenuated vaccines contain a weakened form of the virus. The virus can replicate in your body, but it can’t make you sick. Your immune system sees the virus, mounts an antibody response specific to that virus and is able to recognize that virus in the future. (15/n)
3) Subunit vaccines contain just a component of the pathogen, like for example a protein that is recognized by the immune system. Your immune system sees that protein, mounts an antibody response specific to that virus and recognizes that virus in the future. (16/n)
4) Nucleic acid vaccines consist of a piece of RNA or DNA that encodes a piece of the virus that is easily recognized by the immune system. Once the RNA or DNA ends up in your cells, it acts as a template to make that piece of the virus. (17/n)
Your immune system sees that piece of the virus, mounts an antibody response specific to that virus and is able to recognize that virus should you become infected in the future. (18/n)
Which vaccine approach is being considered for COVID-19? All of the above. One that is in Phase I Clinical trials right now (developed by NIAID and Moderna) is an RNA vaccine (category 4 above) that encodes the spike protein of the coronavirus. (19/n)
This spike protein is embedded in the outside shell of the virus and is needed for the virus to attach to a host cell. If a patient is immunized with this vaccine, the RNA would enter cells and the spike protein would be made. (20/n)
Hopefully, your immune system would make antibodies to that spike protein. If it works, it should be highly effective because it is known that antibodies to the spike protein neutralize (inactivate) this virus. (21/n)
How does immunity work? Why is it that some vaccines only cause short-lived immunity? Does immunity wind down as time passes? Is ultimate immunity impossible? There are different types of immunity. The one relevant in the context of vaccines is adaptive immunity. (22/n)
The way it works is that some immune system cells specific to a little piece of a particular virus are able to recognize that virus the first time they see it. They then divide a lot, make more copies of themselves and over time become better at protecting against the virus. (23/
Sometimes those cells can live for a really long time. However, sometimes they don’t. Depending on the microbe, there can be a lot of variation in the length of immunity. (24/n)
There are stories in the news about younger people getting very sick from this virus and that the virus is all of a sudden “targeting young people.” Yes, younger people can get sick too, but the rate of death is much lower in younger people. (25/n)
The initial numbers from China (that fatality rate increases with age) still hold true across the board. For example, a recent study done in Italy shows that there were no deaths in people under the age of 29, and that risk of death from this disease increases with age. (end)
