Coronavirus Flashcards
Describe the structure of Coronavirus
-Coronaviruses are the only +ssRNA virus with a helical capsid
-They are all enveloped, and hand sanitizers work on coronavirus
Unlike other RNA viruses, what can coronaviruses do when copying their RNA?
Can proofread when copying their RNA and have a lower mutation rate than other RNA viruses.
-However, they can still change by antigenic drift
Coronaviruses often use ______ to make changes in their genome
recombination
The ________ are known to cause the common cold
HCoV
-They are local infections with an incubation time of 2-4 days
Human coronaviruses (HCoV) are 2nd in causing the common cold - what is 1st?
Rhinovirus
Is immunity entirely protective against human coronavirus?
-Immunity is not entirely protective (wanes after time
-Reinfection with the HCoVs seems to be common
When season are human coronaviruses common?
Winter months
Is Severe Acute Respiratory Syndrome (SARS-Cov) (asymptomatic/symptomatic)?
Symptomatic
-Almost no asymptomatic infections
-Tends to have a higher fatality rate in older patients
How did SARS-CoV emerge?
Emerged due to a bat CoV infecting the palm civet in China and probably adapting in this host for some time before jumping to humans
What did SARS-CoV cause?
-A severe respiratory infection
-As a result, many people were hospitalized and required mechanical ventilation
Why was the spread of SARS-CoV rapid and hard to control?
-Because of ‘super-spreaders’
-These people would infect a large number of people, probably due to high virus loads and aerosolization of the virus
How was SARS-CoV controlled?
By a better diagnosis of the SARS-CoV patients, isolation of those patients, and isolation of all patient contact.
What type of people did not spread SARS?
Asymptomatic or pre-symptomatic
The Middle East Repertory Syndrome (MERS-Cov) has introductions to humans from what animals?
Camels
Unlike SARS-CoV, MERS-CoV is what type of infection?
Mild and asymptomatic infection
What can MERS-CoV cause?
Acute respiratory distress syndrome (ARDS) but also renal disease
How does MERS-CoV infection spread?
-Person-to-person from respiratory secretions
-Most spreading tends to occur in a hospital setting or from household contacts of the infected. (Like SARS-CoV, there tended to be people who facilitate ‘super-spreader events’ which happen in hospital settings for MERS)
The _____ for MERS-CoV is high
CFR
-Like all respiratory infections, there is a higher fatality rate in people with comorbidities, but otherwise, healthy people also die from MERS; this is more likely with increased age
How was the MERS-CoV outbreak halted?
By better diagnosis, faster quarantine of MERS-CoV patients, and extensive quarantine of contacts
SARS-CoV-2 most resembles a ______ coronavirus. The intermediate host _____
bat; unknown
How does MERS-CoV-2 spread?
-Has sustained community spread
-Can spread from asymptomatic people and before people show symptoms
-There are ‘super-spreading events’
What is the CFR for SARS-CoV-2?
-Hard to say
-It is higher the older the person and with the existence of comorbidities
-If hospitals are overrun, then CFR tends to go highr
What is the incubation time of SARS-CoV-2?
2-5 days but can last as long as 12
What are the symptoms of SARS-CoV-2?
There is a wide range of symptoms, but most people start with signs of respiratory tract infections or lack of taste or smell, but some people have GI symptoms
Is SARS-CoV-2 local or systemic?
SARS-CoV-2 can be systemic but remains a local infection in some
There are _____ licensed vaccines available for SARS-CoV-2 in the US
3
The newest SARS-CoV-2 vaccine is a _______ vaccine from Novoxax. It contains….
subunit; it contains an adjuvant in addition to the spike protein and is from the original strain
Two of the SARS-CoV-2 vaccines are mRNA-based vaccines. How do these work?
1) These use an mRNA encoding the spike protein, the receptor-binding protein on the viral surface of SARS-CoV-2. The mRNA enters a cell, and the spike protein is made.
2) The RNA is encoded in a lipid or nanoparticle. Some lipids can act as an adjuvant, as can the RNA itself.
3) The RNA vaccines give a neutralizing antibody response with two doses, but a regular booster will be needed. It will more than likely be like the influenza vaccine with regular boosters needed and change with the most prevalent strain.
4) If people have previously had SARS-CoV-2, it is recommended that they get the vaccine. It
will boost their neutralizing antibodies.
All SARS-CoV-2 vaccines seem to work very well at preventing hospitalization and death. However, the more the virus changes, the less well the original vaccines prevent infection. What is this due to?
The virus mutating to escape neutralizing antibodies
Currently, the ______ variants are the only detected variants in the world. However, subvariants of ________ occur fairly regularly, supplanting the old ______ subvariants
Omicron (for all blanks)
Three antivirals and some monoclonal antibodies are used to treat SARS-CoV-2. ______ is only for non-hospitalized, and _______ is for mild to severe infections
Paxlovid; Remdesivir
What is Paxlovid?
A combination pill with two components:
-A protease inhibitor against the main protease of SARS-CoV-2
-Component that keeps the level of inhibitor more steady
When and how is Remdesivir given?
-Given via IV injection and in a nucleotide inhibitor of SARS-CoV-2’s RNA-dependent RNA polymerase
-It can be given early to prevent hospitalization or upon hospitalization
Many different neutralizing monoclonal antibodies are given via IV. However, the monoclonal antibodies…..
do not work on all of the variants
Tests for SARS-CoV-2 infection are _______ and _______
PCR based and antigen-based
-The at-home kits are antigen-based and work when there are high enough levels of the virus to be detected
-PCR tests are more sensitive and can detect lower amounts of the virus
