COVID-19 FREQUENTLY ASKED QUESTIONS

Why are children less susceptible to COVID19 infection?

          Fewer out door activities

          Less travel

          Fewer ACE receptors in respiratory tract

          Lower levels of cytokines

          Immune protection from Coronavirus (CV) of common cold

          Better function of T helper cell in children

 

Do children transmit less CV?

          Pre-pubescent less chance of illness (<12 years)

          Smaller lungs do not project droplets

Per Cent of COVID 19 patients asymptomatic?

          Transmit 24-48 hrs before signs

          Approximately 20%

Will asymptomatics have symptoms?

          80%

Symptomatics versus asymptomatics viral shedding?

          Symptomatic patients 19 days

          Asymptomatic patients 17 days

 

Per cent of COVID19 cases spread by asymptomatics?

          40%

 

How safe are current vaccines?

          Rare side effects

 

CV vaccine effectiveness versus others?

          Flu 40-60%

          Pediatric vaccines 90-99%

          Moderna 94.5%

          Pfizer 95%

          Astra Zeneca 70%

 

Can a patient be re-infected with COVID19?

          Yes

Duration of vaccine protection?

          Approximately 3 months (based upon current data)

 

COVID19 incubation period?

          7 days

How long do patients shed virus?

          median 22 days

 

Phase of COVID19 illness & viral shedding

          Pre-symptomatic 11.5 days

          Mildly symptomatic up to 10 days

 

Why CV vaccines need ultra cold storage?

          mRNA fragile

          Lipid nanoparticle unstable

 

Do masks work?

          Prevents patients with CV from spreading virus via aerosol droplets

          Limits exposure to droplets

 

Is reduced ambient temperature & RH enhance CV spread?

          In colder weather people spend more time indoors

          Reduced amount of H2O vapor per unit of air at low temperature, holds more virus

          COVID19 better at 40-60% RH versus 20%

          Dry respiratory tract less mucosal clearance of particles

          Less sunlight leads to lower Vitamin D levels

          Cold air causes vasoconstriction/microscopic tears

          Dry air reduced RH, reduces size of aerosol droplets due to evaporation prolongs                airborne spread * buy a humidifier

 

On what surfaces is CV most stable?

          CV less stable on copper, copper nickel or brass

          CV more stable on stainless steel, zinc, glass, ceramic, rubber

          Greater survival=greater porosity

 

How long are COVID19 aerosols infectious?

          At room temperature 68-72 F (20-22C), and 65% RH

          an aerosol lasts approximately 3 hours

 

Do weather/climate determine where COVID19 occurs?

          There is currently no conclusive data demonstrating

          variations in climate effect COVID19 transmission.

          However, countries with colder climates need stricter

          public health measures.

 

What is a virus?

          A bad piece of news wrapped in protein with a

          sketchy set of engineering specifications.

          The viral genetic material is its software.

 

Are genetic mutations always bad?

          most point mutations are silent

          if they confer a selective advantage, they will be selected

 

List the MOST important vaccines for children?

          Chicken pox

          Polio

          Haemophilus Influenzae B

          Influenza

          Diptheria, Tetanus, Whooping cough (DTaP)

          Measles, Mumps, Rubella (MMR), Hepatitis B

 

How effective are the typical childhood vaccines?

          Typically these vaccines are 90-99% effective

 

How safe are the typical childhood vaccinations?

          These vaccines are very safe. Millions of children receive

          them every year.         

          No correlation exists between vaccines and autism.

          Serious allergic reactions (anaphylaxis) 3.5/10 million

          vaccinations. ISRs in10%, and fever in 2%.

 

What is the primary route of COVID19 transmission?

          The primary means is via respiratory droplets

          (40,000 droplets/sneeze)

          Large droplets settle quickly due to gravity

          Smaller droplets evaporate to form aerosol particles

          Low temperature/high RH favor droplets

          High temperature/low RH favor aerosols

          Extreme cold/humid scenarios droplets can reach 6M (19’22”)

          Social distance of 1.4M (4’8”) blocks 95% droplet transmission

 

The Course of COVID19 Disease?

          Incubation period 5-7 days

Initiation of symptoms day 1: viral load peaks (48hrs after symptoms)

          Mild symptoms thru day 5-6 (hospitalization)

          Severe illness day 10

          Critical illness days 10-12 (ICU)

          Antibodies day 12-14

         

What is the difference between a light microscope & EM?

          Beam of electrons versus light

          Electrons shorter wave length=higher resolution

          LM resolution 0.05 uM vs EM resolution 0.02 nM

          LM magnification 500-2000X versus EM 200000X

          Scanning EM cost $1M

 

Compare genome sizes: Virus, Bacteria, Man

          Virus measured in kB (10X3): 10-1600 genes: 16 proteins

          Bacteria measured in Mb (10X6): 5000 genes: 1600 proteins

          Man measured in Gb (10X9): 25,000 genes: 20,000 proteins

 

COVID19 TESTS

          FDA granted emergency use authorization (EUA) for 100s diagnostic tests.

 

PCR/vRNA/NATS)

           False negative 20-100%, earlier >FN rate

           False positive 0%

           Nasal swab

           Results: 1 hr-24 hrs

Viral Antigen Tests

           Protein fragments, not NA

           False negatives > PCR

           False positive 0%

           Nasal swab

           Results in minutes

Antibody Testing (serologic testing)

           14 days PI IgG

           False negatives 20% (0-30%)

           Positive test # protective immunity/Or lack of contagiousness