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January 8th, 20201 – COVID Mutations

Hello,

First, a bit of good news. The new website is live and Admin EM has completed the transition to Learn EM. COVID-19 resources that were previously available only to subscribers are now free to all. These include:

All of these resources can be found at https://learnem.org in the COVID-19 section.

This has been a difficult week for the U.S. for many reasons. The COVID pandemic is worse than it has ever been with a historic high number of daily hospitalizations and deaths. Every hospital in the country is feeling the strain while case counts continue to rise. This week’s newsletter includes a closer look at mutations and their impact on the world.

Sam


COVID Mutations

As viruses infect people and replicate, they accumulate mutations. The more infections, the more opportunities for mutations. This is occurring with SARS-CoV-2, the virus responsible for COVID-19 infections. The SARS-CoV-2 variant labeled B117 has several mutations, and was first reported in the U.K. Although it was first sequenced in the U.K. , where it is currently the dominant variant, its origin is not clear. However, it has also been detected in multiple U.S. states including California, Colorado, Florida, Georgia, and New York. COVID positive samples from the U.S. are randomly tested by the CDC as part of ongoing surveillance. No travel exposures have been linked to the cases suggesting that there is already local spread of this variant in the U.S. This B117 variant has been reported to be more infectious (easier to spread) but not more lethal.

How do we know it is more infectious?
Data is primarily derived from contact tracing and testing of positive samples. Surveillance in the U.K. reveals that 15% of contacts become infected with B117 compared to about 10% of contacts infected before this variant.

Is it more lethal?
Available data shows an increase in total cases without an increase in the percentage of hospitalizations. But this is still bad news. Even with no change in the percent of hospitalizations and deaths, more infections still result in more people hospitalized or dead.

Is the vaccine effective against it?
Yes, as far as we know. This variant has accumulated multiple mutations, one of which is in the spike protein. However, it is still believed that the vaccines currently available are effective. Both Moderna and Pfizer vaccines cause an immune response against the S (spike) protein of SARS-CoV-2. Multiple antibodies are generated against different parts of this protein, making this response “polyclonal”. That means a single mutation in the S protein will not bypass the immunity generated by the vaccines.

Are there other variants?
Yes. Another variant is currently being tracked in South Africa and has also been reported in Brazil. This variant includes the same S-protein mutation (N510Y) contained in the B117 variant. However, the South Africa variant also includes another key mutation (E484K). This mutation is in the receptor binding domain and is thought to interfere with antibodies that bind in this area. Further study and close monitoring is ongoing. More information about variants being tracked worldwide is available from the World Health Organization.

Further reading:

  • https://www.sciencemag.org/news/2021/01/viral-mutations-may-cause-another-very-very-bad-covid-19-wave-scientists-warn
  • https://www.statnews.com/2021/01/07/coronavirus-mutation-vaccine-strength/?utm_source=join1440&utm_medium=email
  • https://www.prospectmagazine.co.uk/science-and-technology/new-strain-variant-covid-19-coronavirus-lockdown-schools

Vaccines

The CDC reports that over 21 million doses of covid vaccines have been distributed and almost 6 million have been administered to patients so far. Vaccine availability to at risk populations varies by state. Some states have already begun vaccination of people over age 65, while others are still focused on frontline healthcare workers. Local Health Departments have information regarding distribution in your area and serve as a good information resource. It will be some time before vaccines are available to the general public. Also, availability for children is still months away as studies in children are yet to be completed.


ICUs Are Over Capacity

Southern California is in the midst of a severe surge resulting in a lack of ICU space. This is not unique to California, multiple other states are in similar situations due to an increase in COVID hospitalizations.

However, one county in Southern Ca. made the news after changing its policy regarding transportation of patients to emergency departments. It was reported that paramedics were told not to transport patients, but this is not an accurate depiction. The policy change effects situations where someone has a cardiac arrest. Traditionally, paramedics have begun resuscitation at the scene and continued CPR and other heroic efforts while en route to the hospital. The new policy states that paramedics are to initiate efforts at the scene with CPR and two rounds of IV medications. If this does not result in return of a pulse, the patient is pronounced dead and not transported to the emergency department.

Few people survive out-of-hospital cardiac arrest, and resuscitative efforts are known to consume large quantities of resources: equipment, medications, and personnel. As hospitals in the region struggle due to capacity and limited supplies, changes like these allow this population of patients to avoid using emergency department resources that must be devoted to others who are still living. However, this does serve as a sobering example of the steps some health systems must take to combat capacity.

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