# Model-informed COVID-19 vaccine prioritization strategies by age and serostatus

###### tags: `articles`
[Note of Shen(2022/3/2)](https://hackmd.io/NJRqEdYvQ-mKCSF3914P7w?both)

## Introduction

Compare the impact of different COVID-19 vaccine prioritization strategies
<!---
with variation in 3 areas

Variations:
1. Variation in performance of the vaccine (vaccine efficacy)
2. Variation in infection and fatality rate by age
3. Variation in age distribution, age stratified contact rate.
--->

There are two main approaches to vaccine prioritization:
1. vaccinate those at highest risk for severe outcomes
2. vaccinate those who do the most transmitting

## Details of the Model

- SEIR model: [Supplement material](https://hackmd.io/@xxoooxx345678/Syo2iyDxK)

- Input
- **strategy**
- age-dependent contact matrix
- susceptibility to infection rate
- infection fatality rate
- infectious period
- latent period
- $R_0$
- vaccine efficacy
- ...
- Output (Performance of the strategy)
- cumulative incidence of infections
- mortality
- years of life lost (YLL)

## Impacts of vaccine prioritization strategies on mortality and infectious

`Vaccines with 90% efficacy, 0.2% rollout/day`

- Prioritizations
1. under 20
2. adults between ages $20$ and $49$ years
3. adults $20$ years or older
4. adults $60$ years old or older
5. all individuals


Scenario 1: $R_0=1.15$
Scenario 2: $R_0=1.5$

## Impact of transmission rates, age demographics, and contact structure

`Vaccines with 90% efficacy`


## Variation in vaccine efficacy by age


scenario 1: $R_0=1.15$
scenario 2: $R_0=1.5$


## Incorporation of population seroprevalence and individual serological testing

`Vaccines with 90% efficacy, 0.2% rollout/day`
$R_0=1.5$


## Supplement

### More Complicated Model

Considering
- vaccine hesitancy
- pre-transmission rollout
- variable rollout rate
- imperfect serological tests
- ...

### Impact of vaccine efficacy

scenario 1: 0.2% rollout/day, $R_0=1.15$
scenario 2: 0.2% rollout/day, $R_0=1.5$
scenario 3: pre-transmission vaccination, $R_0=1.5$
scenario 4: pre-transmission vaccination, $R_0=2.6$

> $R_0$ of the delta variant is 5~8


### Impact of rollout speed