Round 5

In Round 5, we aim to inform 2023 autumn COVID-19 vaccination campaigns in the EU/EEA. In particular, we explore the impact of one intervention and one biological scenario axis on the COVID-19 burden in the EU/EEA. The first axis explores different scenarios on the autumn 2023 vaccination campaign. The second axis relates to the extent of waning immunity that is obtained from past vaccinations, past infections, or both (hybrid immunity), given the uncertainty around this property as well as its impact that we have seen in earlier modelling rounds.

• We request submissions by 20 August 2023
  • Scenario details
  • Submission information and key dates
  • Any feedback is welcome

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Round 5 scenarios

	No vaccination	Pessimistic vaccination 60+ booster with -50% of flu vaccination uptake*	Optimistic vaccination 60+ booster with +15 percentage points of flu vaccination uptake* (capped at 100%)	Upper boundary vaccination 60+ booster with 100% coverage **
Optimistic waning Protection against infection: 6 months median time to transition to 70% of the initial immunity Protection against severe outcomes: no waning	Scenario A	Scenario B	Scenario C	Scenario D
Pessimistic waning Protection against infection: 6 months median time to transition to 40% of the initial immunity Protection against severe outcomes: 6 months median time to transition to 80% of the initial immunity	Scenario E	Scenario F	Scenario G	Scenario H

* Referring to country-specific influenza vaccination coverage observed in the past (data will be provided by ECDC)

** This scenario assumes 100% vaccination coverage of all individuals aged 60 years and above (even if they haven't been vaccinated before)

Below we cover scenario details for:

• Waning of protection
• Vaccination
• Additional assumptions

See elsewhere: data links for cross-European data sources and round 5 vaccination values per country, age group, and scenario.

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Waning of protection

We consider two scenarios for immunity waning.

• Optimistic waning

  • Protection against infection: 6 months median time to transition to 70% of the initial immunity (decrease of 30%)
  • Protection against severe outcomes: no waning

• Pessimistic waning

  • Protection against infection: 6 months median time to transition to 40% of the initial immunity (decrease of 60%)
  • Protection against severe outcomes: 6 months median time to transition to 80% of the initial immunity (decrease of 20%)

Example: If your VE against infection has initial value of 80%, it should take value of 56% (70% of 80%) or 32% (40% of 80%) after 6 months for optimistic and pessimistic waning scenario, respectively. The exactly functional shape of waning immunity is left to the teams.

Shared assumptions

We ask all modellers to include the following parameters:

• No plateau existing for immunity against infection
• The parameters for the waning speed of protection relate to the waning since the most recent vaccination or infection

Assumptions left to modeller judgement

Modellers should use their own judgement and relevant literature if making assumptions about the following:

• Functional shape of waning immunity against infection and against severe outcomes (following the above specified decrease of immunity against infection within the specified time frame)

Vaccination

Based on the data obtained from the WHO Immunisation Dashboard and OECD, we have collected the flu vaccination uptake values for the 2022/2023 season in each EU/EEA country. In cases where the latest data was not available, we used the most recent information excluding the 2020/2021 and 2021/2022 seasons due to the impact of the COVID-19 pandemic on flu vaccination rates.

Since the flu vaccination uptake data is only provided for the older population as a whole and not for individual age groups (60-69, 70-79, 80+), we utilized the COVID-19 first booster uptake data to determine how the future COVID-19 vaccination uptake will be distributed among different age groups in each country. This means that the proportions of future COVID-19 vaccine uptake between various age groups are assumed to be the same as those observed during the first booster COVID-19 vaccination campaign.

The vaccination values per country, age group, and scenario for round 5 can be found here.

Shared assumptions

• The vaccination campaigns begin on 01-10-2023 and last for 90 days
• New vaccinates will not be a "game changer" in terms of VEs
• No additional new vaccination campaigns, except those specified in the scenarios

Assumptions left to modeller judgement

• Vaccination (and uptake levels) of at-risk individuals of all ages as well as vaccination of healthcare workers

Additional assumptions

Shared assumptions

• Data sources used: please use ECDC provided data for death and hospitalisation incidence, while you can use any data source for case data. (For countries that have discontinued reporting of an epi indicator, we ask teams to initiate model projections starting at the last reliable data point.)
• No new variants
• No new public health and social measures (non-pharmaceutical interventions / NPIs)
• No changes in demography
• No novel drugs that significantly alleviate the COVID-19 burden

Assumptions left to modeller judgement

• The absolute value of vaccine effectiveness and protection from past infections for all outcomes
• Contact rates in response to infection rates
• Impact of seasonality, including seasonal behavioural changes

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Submission information

• Projections
• Key dates

Projections

Projection period

• Projection period is 1st August 2023 to 1 June 2024

Targets

Teams can submit any of the below targets.

Target	target_variable	Notes
Incident infections	inc infection	Please only provide incident cases (inc case) if unable to model infections
Incident hospital admissions	inc hosp	We no longer ask for ICU (critical care) admissions
Incident deaths	inc death
Vaccine doses administered	inc dose	New target - essential to future calculations of vaccine cost-effectiveness between scenarios

Age groups

We ask for submissions to include results for each of three age groups, identified in a new column age_id. We suggest age brackets below.

Age group	age_id
Children (0-17 years)	child
Adult (18-59 years)	adult
Older population (60+ years)	older
Age breakdown not available	Do not include age_id column

• If your model is already age-structured and it is difficult to change the exact age-bands, please follow as closely as you can and let us know where your age-groups differ
• If a breakdown by age is not possible, please continue to submit for all age groups combined (and leave out the age_id column)

Scenario IDs

Please use the following codes to identify between scenarios in the scenario_id column, with one for each value (row) in your submission csv.

Scenario	scenario_id
Scenario A. No vaccination, optimistic waning	A
Scenario B. Pessimistic vaccination, optimistic waning	B
Scenario C. Optimistic vaccination, optimistic waning	C
Scenario D. Upper boundary vaccination, optimistic waning	D
Scenario E. No vaccination, pessimistic waning	E
Scenario F. Pessimistic vaccination, pessimistic waning	F
Scenario G. Optimistic vaccination, pessimistic waning	G
Scenario H. Upper boundary vaccination, pessimistic waning	H

Model abstract

Please include an abstract for your model as part of your submission.

• Copy the Round 5 Abstract template
• Complete where you can - all comments are appreciated
• Save this to the model-abstracts/2023-08-01 folder, adjusting the filename to MyTeam-MyModel.md

Key dates

The dates for Round 5 are:

	Round 5 date
Submissions due	20th August 2023
End date for fitting data (last day of epiweek)	31st July 2023
origin_date (first possible date of a daily simulation)	1st August 2023
Last day of projections	1st June 2024