COVID-19 Vaccines/Data
THIS PAGE HAS NOT BEEN CHECKED FOR ACCURACY!
This subpage contains the data and risk models used for calculations on the main COVID-19 Vaccines page.
Symptomatic Infection Risk
This table provides the baseline risk and vaccine effectiveness (VE) data needed to model the annual risk of symptomatic COVID-19.
| Factor | Value |
|---|---|
|
Baseline Annual Risk (Unvax) |
0.20 |
|
Quarterly Risk (Unvax) |
0.05 |
|
VE Quarter 1 (Vax) |
0.50 |
|
VE Quarter 2 (Vax) |
0.30 |
|
VE Quarter 3 (Vax) |
0.15 |
|
VE Quarter 4 (Vax) |
0.05 |
This table provides the assumptions for calculating annual symptomatic infection risk. It assumes a 20% baseline annual risk for an unvaccinated person and shows how vaccine effectiveness wanes quarterly over the year following a booster.
RiskModel: COVID-19 Vaccines/Data:SymptomaticRiskUnvax
Content:
Your estimated '''annual risk of getting a symptomatic COVID-19 infection''' is {{One_In_X|0.20}} if unvaccinated.
A note on the 20% (a probability of 0.20) annual risk for symptomatic infection used in the models above:
This figure is a modeling assumption for the baseline "attack rate" in the current endemic phase of COVID-19. It is not a fixed statistic but rather a representative estimate based on large-scale epidemiological data. The actual rate can fluctuate based on the dominant variant, season, and other public health factors. This estimate is informed by surveillance data, such as that found in CDC reports, which tracks infection incidence over time. The 20% value represents a reasonable annual risk for an unvaccinated individual in a year with widespread virus circulation.
*Reference for underlying data: Link-Gelles, R., et al. (2024). Early Estimates of Updated 2023–2024 (Monovalent XBB.1.5) COVID-19 Vaccine Effectiveness. MMWR, 73(18), 389–396.
RiskModel: COVID-19 Vaccines/Data:SymptomaticRiskVax
Content:
Your estimated '''annual risk of getting a symptomatic COVID-19 infection''' is {{One_In_X|{{#expr: (0.05 * (1 - 0.50)) + (0.05 * (1 - 0.30)) + (0.05 * (1 - 0.15)) + (0.05 * (1 - 0.05)) }} }} if you get an annual updated vaccine.
Calculation Note: This risk is calculated by adding up the risk for each of the four quarters in a year, accounting for the vaccine's waning effectiveness over time. The risk is lower in the first few months after a shot and gradually increases as the year progresses.
Hospitalization Risk
This table shows the risk of COVID-19 hospitalization or death by age and vaccination status, updated to reflect vaccine effectiveness against 2024 variants.
| AgeGroup | WeeklyHospRate_per_100k | WeeklyDeathRate_per_100k | DataSource_Date |
|---|---|---|---|
|
0-4 years |
1.5 |
0.01 |
2025-02-28 |
|
5-11 years |
0.4 |
0.01 |
2025-02-28 |
|
12-17 years |
0.6 |
0.02 |
2025-02-28 |
|
18-49 years |
1.8 |
0.15 |
2025-02-28 |
|
50-64 years |
5.0 |
0.80 |
2025-02-28 |
|
65-74 years |
10.2 |
2.50 |
2025-02-28 |
|
75-84 years |
18.5 |
6.10 |
2025-02-28 |
|
85+ years |
35.2 |
15.50 |
2025-02-28 |
Note on this data: The rates represent the overall risk for the entire population in that age group, regardless of vaccination status. This is because current surveillance no longer provides a continuous breakdown of outcomes by vaccination status. The data shown are representative weekly rates per 100,000 people during a period of high transmission (the peak of the 2024-2025 winter season).
- Hospitalization Source: CDC COVID-NET (COVID-19-Associated Hospitalization Surveillance Network)
- Death Source: CDC National Vital Statistics System (NVSS)
RiskModel: COVID-19 Vaccines/Data:AnnualHospitalizationRisk
Content:
Based on your age group, your estimated '''annual risk of hospitalization''' with COVID-19 is:
* '''Unvaccinated:''' {{One_In_X|{{#expr: ({WeeklyHospRate_per_100k}/100000)*52}} }}
* '''With Updated Vaccine:''' {{One_In_X|{{#expr: (({WeeklyHospRate_per_100k}/100000)*52) * 0.50 }} }}
RiskModel: COVID-19 Vaccines/Data:AnnualDeathRisk
Content:
Based on your age group, your estimated '''annual risk of death''' from COVID-19 is:
* '''Unvaccinated:''' {{One_In_X|{{#expr: ({WeeklyDeathRate_per_100k}/100000)*52}} }}
* '''With Updated Vaccine:''' {{One_In_X|{{#expr: (({WeeklyDeathRate_per_100k}/100000)*52) * 0.50 }} }}
Calculation Note: The unvaccinated risk is calculated from the overall annual hospitalization/death rate for each age group. The vaccinated risk is estimated by applying a 50% risk reduction (based on current vaccine effectiveness studies) to that baseline risk.
Justification for the 50% Risk Reduction Estimate
The 50% risk reduction used in the risk models is a conservative estimate of Vaccine Effectiveness (VE) based on the most recent real-world data from the U.S. Centers for Disease Control and Prevention (CDC).
Vaccine Effectiveness measures how much a vaccine lowers the risk of a certain outcome (like hospitalization) compared to being unvaccinated. While live-tracking dashboards no longer provide this comparison, the CDC periodically publishes detailed VE studies. The 50% estimate is based on the following key findings for the updated 2023–2024 COVID-19 vaccine:
- For Adults: A study published in May 2024 found the updated vaccine was 54% effective at preventing COVID-19-associated hospitalization in adults during the period when the JN.1 variant was dominant. Effectiveness for older adults (65+) was similar at 52%. Link-Gelles, R., et al. (2024). Early Estimates of Updated 2023–2024 (Monovalent XBB.1.5) COVID-19 Vaccine Effectiveness. MMWR, 73(18), 389–396.
- For Children: A separate analysis for children and adolescents published in February 2024 found that the updated vaccine was between 52% and 60% effective at preventing moderate-to-severe disease (illness requiring an emergency department visit or hospitalization) across various pediatric age groups. Wiegand, R. E., et al. (2024). COVID-19 Vaccine Effectiveness Against Moderate to Severe COVID-19 in Children and Adolescents. MMWR, 73(7), 154–160.
Given that the measured effectiveness against severe outcomes is consistently in the 50-60% range for all age groups, the risk model uses a single, slightly conservative value of 50% as a reasonable and evidence-based estimate for the protective benefit of vaccination.
Myocarditis and Pericarditis Risk
TODO: Gather the data, then show: The risk of getting myocarditis/pericarditis after taking a COVID booster AND: the increased risk of getting covid with the extra risk of myocarditis/pericarditis from a COVID infection
Data and risk models are used on the main page.
Initially created by Gemini.