Round 2

We have now completed Round 2.

With this scenario round, we were aiming to create results that are relevant both for teams’ national policy work, and for cross-European policy setting for a vaccination campaign in the autumn. We've focussed on the target population for a second booster vaccination among those aged 60+ or all 18+; combined with optimistic and pessimistic scenarios for the effectiveness of a second booster dose. A wide range of possibilities for the latter has been plausible, from increased effectiveness of new vaccines, to reduced effectiveness of existing vaccines against new variants. As a result, we have kept the quantification of these scenarios particularly flexible and open to modellers’ independent judgement.

We have asked for projections over a period of at least nine and at most twelve months.

• Submissions solicited by 29 July 2022
  • Submission information, key dates, and model abstract below
  • Let us know if you need more time

Round 2 scenarios

	Age 60+ booster campaign 2nd* booster recommended for 60+ Uptake starts 15th September, and reaches 50% coverage by 15th December	Age 18+ booster campaign 2nd* booster recommended for general population, ages 18+ Uptake starts 15th September, and reaches 50% coverage by 15th December
Optimistic vaccine effectiveness Increased booster vaccine effectiveness to that seen against Delta variant	Scenario A	Scenario B
Pessimistic vaccine effectiveness Reduced booster vaccine effectiveness against infection from BA.4/BA.5/BA.2.75 variants	Scenario C	Scenario D

* If a second booster is already offered, vaccination uptake continues as currently and a third booster dose is recommended

In this section we cover scenario details for:

• Booster campaign

• Vaccine effectiveness

• Additional shared assumptions

See also:

• Round 2 submission information

• Data links for cross-European data sources

Booster campaign {#booster-campaign}

We consider scenarios for a second booster vaccination campaign among the population aged 60+ or the general population in each country. This vaccination would typically be a fourth dose, following a completed course of two doses plus a first booster dose. We prescribe a relative reduction in vaccination coverage among the target group (see: shared assumptions).

In the scenarios we vary only the target population of the booster campaign:

• 60+ age group (scenarios A & B)

• 18+ age group i.e. the general population (scenarios C & D)

Where second booster vaccination is already available, please model booster vaccination uptake as it is continuing now; for those who have already had a second booster, please model a third booster (fifth dose), with otherwise the same parameters.

Assumptions about the booster campaign

Shared assumptions

All modellers should include the following parameters when modelling the booster campaign:

• Uptake starts on 15 September

• By 15 December, coverage among the target population reaches 50% of coverage achieved by the first booster campaign among that population

Assumptions left to modeller judgement

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

• The existing level of vaccination coverage reached in the first booster campaign

• Previous vaccinations' vaccine effectiveness against COVID-19 outcomes

Vaccine effectiveness {#vaccine-effectiveness}

We look at varying levels of the effectiveness of a booster vaccine providing protection against COVID-19 outcomes. The value of vaccine effectiveness should be against any variant, with effectiveness:

• Increased: a second booster gives equivalent protection to that of a first booster vaccination against Delta

  • This scenario aims to represent possible newly formulated vaccines specific to current/new variants
  • For example: Zeng et al. find a 95% VE for a first booster against Delta variant

• Reduced: a second booster gives relatively lower protection against infection from BA.4/BA.5/BA.2.75

  • This scenario aims to represent possible reduced efficacy of current vaccines against infection from new variants (including BA.4/BA.5). We note that protection against other outcomes is left to modeller judgement
  • For example: very early data from the ECDC indicates a -20% decrease in efficacy of vaccination against BA.4/BA.5 (BA.2.75 unknown)

Assumptions about vaccine effectiveness

Assumptions left to modeller judgement

Modellers should use their own judgement and relevant literature to make assumptions about:

• The absolute value of vaccine effectiveness from either

  • A booster vaccine giving equivalent protection to that observed against the Delta variant

  • A booster vaccine giving reduced protection from BA.4/BA.5/BA.2.75

• Vaccine-induced protection against severe disease and death

While we emphasise that these parameters are open to modeller judgement, we have identified the following useful references (please note this is not from a systematic literature search):

• Zeng, B., Gao, L., Zhou, Q. et al. Effectiveness of COVID-19 vaccines against SARS-CoV-2 variants of concern: a systematic review and meta-analysis. BMC Med 20, 200 (2022). https://doi.org/10.1186/s12916-022-02397-y

• Higdon MM, Baidya A, Walter KK, Patel MK, Issa H, Espié E, Feikin DR, Knoll MD. Duration of effectiveness of vaccination against COVID-19 caused by the omicron variant. Lancet Infect Dis. 2022 Jun 22:S1473-3099(22)00409-1. doi: 10.1016/S1473-3099(22)00409-1. Epub ahead of print. PMID: 35752196; PMCID: PMC9221361.

• VIEW-Hub vaccine data repository

Additional assumptions {#additional-assumptions}

We ask modellers to use their own judgement when modelling the following:

• Waning immunity

  • We suggest that immunity wanes to a 60% reduction over 8 months from baseline levels (where the baseline is the level of protection reported immediately after exposure (vaccination or natural infection))

  • Teams are welcome to use alternative estimates of immune waning parameters

  • For additional background on waning immunity, we suggest exploring the scenarios for Round 1

We also ask modellers to assume the following:

• No new variant of concern

• No novel drugs that strongly impact burden

Submission information {#submission-information}

Submission process

• Sample based submissions

  • We no longer ask for results across a quantile distribution

  • Please submit up to 100 samples. If you think more are needed to capture the uncertainty from the outputs, please get in touch. If you cannot provide 100 samples, please submit as many as you can.

  • Each sample should be a single simulation from your model, all with equal probability

  • See more on submission formatting

• Targets

  • Teams can submit one or more of any of the below targets. See more on targets

  • Key targets:

    • Incident deaths

    • Incident cases

    • Incident hospital admissions

  • Additional targets, if teams already produce these:

    • Incident infections

    • Intensive care (ICU) admissions

Key dates {#key-dates}

The dates for round 2 are:

	Round 2 date	Epiweek (conversion)
Submissions due	July 29 2022
End date for fitting data (last day of epiweek)	July 23 2022	EW-29 of 2022
origin_date (first possible date of a daily simulation)	July 24 2022	First day of EW-30 of 2022
Earliest target_end_date (first week of simulated results)	July 30 2022	EW-30 of 2022
Latest target_end_date (projections over 12 months)	July 29 2023	EW-30 of 2023

Scenario IDs

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

Scenario	Scenario ID
Scenario A. 60+ booster campaign, optimistic VE	A-2022-07-24
Scenario B. 18+ booster campaign, optimistic VE	B-2022-07-24
Scenario C. 60+ booster campaign, pessimistic VE	C-2022-07-24
Scenario D. 18+ booster campaign, pessimistic VE	D-2022-07-24

Model abstract

Please include a brief abstract for your model as part of your submission. Please make a copy of the Round 2 Abstract template and save this to your team's folder in data-processed, adjusting the filename format (2022-07-29-MyTeam-MyModel-Abstract.md).