SVIRS Model

divides the human population into four subpopulations: those susceptible to COVID, vaccinated, infected, and recovered from COVID

N(t) = S(t) + V(t) + I(t) + R(t)

COVID-19 #

cause respiratory tract infections that can range from mild to lethal

symptoms

transmitted when people breathe in air contaminated by droplets/aerosols and small airborne particles containing the virus

diagnosis

Viral testing

The standard methods of testing for presence of SARS-CoV-2 are nucleic acid tests, which detects the presence of viral RNA fragments

Imaging

Chest CT scans may be helpful to diagnose COVID‑19 in individuals with a high clinical suspicion of infection but are not recommended for routine screening

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prevention

vaccine

face masks

avoiding crowded indoor spaces

hand-washing and hygiene

social distancing

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Comirnaty (Pfizer/Wyeth)

Coronavac (Butantan)

Janssen Vaccine (Janssen-Cilag)

Oxford/Covishield (Fiocruz e Astrazeneca)

Sputnik

Covaxin (SUSPENSA)

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The first known Covid-19 case was a vendor at the live-animal market in Wuhan, China in december, 2019

variation of SIR model

can be described by a system of ODEs

As of 7 September 2022, more than 6.5 million deaths had been attributed to COVID-19.

INFECTED (I)

SUSCEPTIBLE (S)

RECOVERED (R)

Fever

Cough

Headache

Fatigue

Breathing difficulties

Loss of smell/taste

dSdt=ωrRλS+ωvVϕS

\[ \frac{ \mathrm{d} V}{ \mathrm{d} t} = -(1 - ψ)λV - ω_{v} V + \phi S \]

\[ \frac{ \mathrm{d} R}{ \mathrm{d} t} = γI - ω_rR \]

\[ \frac{ \mathrm{d} I}{ \mathrm{d} t} = λS + (1 - ψ)λV - γI \]

It's a compartmental model, a very general modelling technique. Often applied to the mathematical modelling of infectious diseases, like COVID-19

although those who have recovered become susceptible again at some point