By: 18 March 2021
Whatever happened to Exercise Cygnus?

James Watts, Consultant in Anaesthesia and Critical Care Medicine, East Lancashire NHS Teaching Hospitals Trust, explores what learning points were identified from Exercise Cygnus, and whether the criticism of its implementation is valid.


“The best laid schemes o’ Mice an’ Men gang aft agley” … Robert Burns



Exercise Cygnus was a national Command Post level simulation which took place [1] in October 2016. The purpose of the exercise was to table-top test, in real time, the UK’s resilience to an influenza epidemic, and to identify both strengths and weaknesses in the planning.

A large number of national bodies – including the Cabinet Office, The Department of Health (DH), Public Health England (PHE) and NHS England (NHE) were involved, as well as social care bodies and regional authorities, and those responsible for Local Resilience planning. All in all, nearly 1000 government, healthcare and social care staff participated.

It is widely held that the lessons learnt from the exercise were not implemented, which led to the well-publicised problems experienced with the government’s response to the COVID-19 epidemic. [2]

This article will explore what learning points were identified from the exercise, and whether the criticism of its implementation is valid.



Pandemic influenza had been identified as a severe civil emergency risk to the UK [1]. The government strategy for dealing with such an event was divided into 5 phases: Detection, Assessment, Treatment, Escalation and Recovery.

The Exercise Cygnus scenario involved a hypothetical world-wide pandemic of an H2N2 flu derived from birds, referred to as “Swan Flu”.

The scenario assumed that the UK was in week 7 of the pandemic, and so would concentrate on the treatment and escalation phases of the response.

The following assumptions were made for the purposes of the scenario:

  • The clinical ‘attack rate’ of ‘Swan Flu’ was 25-40%
  • The case fatality rate was 1.5-2.5%
  • That by week 7 there would have been 400000 deaths
  • That approximately 50% of the UK population would have been infected
  • Up to 20% of staff would be absent for various reasons (sickness, child care, shielding etc.)
  • Schools would remain open, and fuel, utility, public transport and food infrastructure would remain unaffected
  • Anti-viral drugs would have an effect on disease spread
  • A vaccine would have been developed, but would not yet be available for delivery to the UK

It is generally reported that the exercise showed that the UK’s key health and care services would be rapidly overwhelmed. [3-6]

In fact, the key learning points were:

  • Although each organisation had resilience plans in place, some were untested; they did not seamlessly interlock; and there was no mechanism of central coordination
  • It was unclear which information needed to be collected in what detail by whom, and which elements of it needed to be forwarded to aid central decision making
  • The estimate that only 20% of staff would be absent from work was thought to be too low. Estimates of up to 50% were suggested
  • There were plans for reverse triage of patients from hospital to the community, but it was unclear how this should be communicated to the public, or how the public might react
  • Messages from central bodies such as NHSE and PHE were often different-sometimes in emphasis, and sometimes in content-, and confusing. Tellingly the report suggested that such discrepancies could create uncertainty that would either undermine the response, or the confidence in it, breeding cynicism and unhelpful conspiracy theories
  • Ventilator and ITU capacity would be inadequate
  • There would be difficulty dealing with mass deaths on such a scale
  • There was no understanding as to how the public would respond to a pandemic situation

The full list of recommendations is included in the Appendix.

As a result, it was assumed that a ‘herd immunity’ response would be the best initial strategy for dealing with such a pandemic [7].

Jeremy Hunt MP, who was Health Secretary at the time, has stated that the exercise had concentrated on the ‘wrong virus’.

Countries that had previously experienced Coronavirus epidemics – SARS, MERS etc – had based their strategy on detection and containment, and had fared much better in terms of mortality and preservation of social structure during the COVID epidemic. Hunt said in an interview with the BMJ “…we were sadly also part of a groupthink that said that the primary way that you respond to a pandemic is the flu pandemic playbook [with a focus on areas like vaccination and boosting hospital capacity], rather than the methods that you would use for SARS and MERS [surveillance and containment, community testing, contact tracing and isolation, and stockpiling personal protective equipment, and ventilators]…it’s why there is this stark difference in the effectiveness of our responses compared with countries in East Asia. That meant that we didn’t have test and trace capability at the outset, but also that we spent much too long deciding to do it.” [8]

COVID and Influenza can both be fatal, but the reality is that COVID-19 patients become infectious sooner, and remain so for longer facilitating spread (see tables 1 and 2). COVID therefore spreads rapidly and remains circulating for longer. It also makes more people sicker. In addition, the turn-around time for flu tests at the start of the 2020 pandemic was shorter than that for SARS-Cov-2 which took over a week in some areas, meaning that the reverse triage into community care beds of patients who were asymptomatic but with undetected disease had the effect of transferring the illness into communities that were full of the highest risk patients.

The rapid escalation of the pandemic meant that the timescales to stockpile PPE, and other equipment such as ventilators were truncated, leading to shortages.

In addition, no thought had been given to how long COVID patients would stay in hospital, stay on ITU and stay oxygen dependent. As a result hospital and ITU beds became a scarce resource more rapidly than assumed, and there was concern about the integrity of oxygen supplies [9, 10]

To place in context it is estimated that annually there may be 1 billion infections with flu of which 290,000-650,000 die (approximately 0.065 fatality rate; it is normally quoted as 0.1%). It is estimated that there have been 118,689,650 cases of COVID 19, of which 2,631,949 died (2.21 case fatality rate) [12-14]

In summary, following exercise Cygnus the UK Government adopted a strategy based on having time to escalate their response, and obtain extra resources for an illness which spread rapidly, had a low overall mortality, for which anti-virals would have a beneficial effect and for which a vaccine – based on previous related vaccines – would have been rapidly available; whereas the correct strategy would have been to concentrate on detection and containment of a disease which infected more people quicker, who stayed in hospital longer, with a higher mortality, for which anti-virals had minimum effect and for which a vaccine would not be available for nearly a year.



There is a truism that there is a tendency in many armies to spend the peace time studying how to fight the last war. Whilst there have been some successes of the UK Government’s current pandemic strategy (eg vaccination programme) there have been some questionable decisions, and some actions which have had unintended consequences, which may be due to the planning assumption that there could be no worse pandemic than a type of flu. It is to be hoped that future strategies will identify the lessons to be learnt from the COVID-19 pandemic to produce an ultimately more robust and effective plan.



  1. PHE Exercise Cygnus report Tier 1 Command Post exercise pandemic Influenza 18-20 October 2016 2017 accessed 14 March 2021
  2. Nuki, Paul; Gardner, Bill (28 March 2020). “Exercise Cygnus uncovered: the pandemic warnings buried by the government”The TelegraphISSN0307-1235)
  3. Carrington, Damian (29 March 2020). “UK strategy to address pandemic threat ‘not properly implemented. The Guardian. ISSN0261-3077. Retrieved 14/03/2021.
  4. Lambert, Harry (16 March 2020). “Government documents show no planning for ventilators in the event of a pandemic”. New Statesman. Retrieved 14/03/2021.
  5. Smyth, Chris (27 December 2016). “NHS fails to cope with bodies in flu pandemic test”. The Times. ISSN0140-0460. Retrieved 14/03/2021.
  6. “Nick Ferrari’s extraordinary exchange with Care Minister over pandemic test exercise”. LBC. 30 March 2020. Retrieved 14/03/2021.
  7. Gardner, Bill; Nuki, Paul (18 April 2020). “Covid-19 strategies: Britain planned for herd immunity while Asia intended to contain virus”The TelegraphISSN0307-1235. Retrieved 14/03/2021.
  8. Iacobucci G Jeremy Hunt: I was too slow to boost the NHS workforce—the government must, and can, act now BMJ 2021;372 Retrieved 14/03/2021
  9. Lintern S Coronavirus: Hospitals warned problems with oxygen supply will be worse than first wave Friday 20 November 2020 the Independent Retrieved 14/03/2021
  10. Lintern S London Hospital declares major incident over oxygen supply fears 28 December 2020 The Independent Retrieved 14/03/2021
  11. Petersen E, Koopmans M, Go U et al Comparing Sars-COV-2 and Sars-COV and influenza Pandemics The Lancet V 20:9 E238-E244 03/07/2020 Retrieved 14/03/2021
  12. FullFact How does the new coronavirus compare to influenza? March 2020 Retrieved 14/03/2021
  13. Centres for Disease Control and Prevention Similarities and differences between Flu and COVID-19,by%20infection%20with%20influenza%20viruses. Retrieved 14/03/2021
  14. Maragakis LL Coronavirus 2019 vs the Flu John Hopkins Health Retrieved 14/03/2021



The full recommendations of the Exercise Cygnus report (1)

  1. Corporations are required to update their “Emergency Preparedness Resilience and Response training and exercising” for optimum performance
  2. Expert advice from all stakeholders should be readily presented to SCGs for corresponding response. This should occur efficiently so multiple LRFs can benefit from this support.
  3. Planning should occur on a national level, and take into account how local pandemic flu strategies can be operationalised in implementation.
  4. The health tripartite (DH, NHS England and PHE) and Chief Medical Officers (CMOs) should have Cobra Meetings incorporated into flu response
  5. More research needs to be done to investigate if population-based triage is viable during a critical, widespread influenza pandemic
  6. More work is required to understand surge arrangements when the pandemic becomes overwhelming. NHS England should direct the operational side while DH should give management, guidance and policy direction with advice from the Four Nations CMO meeting.
  7. DH should collaborate with partners to understand how antivirals may be used in a pandemic.
  8. PHE and NHS England must cooperate to improve current community guidelines and deliver antivirals within restrictions stipulated by NHS Emergency Preparedness staff.
  9. All corporations must be prepared for increased staff absence in the midst of a pandemic and make appropriate plans.
  10. Pandemic plans need to be effectively communicated to public for reassurance, and the right amount of detail of disclosed information should be ascertained.
  11. Steps to release information to public should be coordinated by DH, NHS England and PHE national teams together with Devolved Administrations
  12. A variety of stakeholders needs to be involved during communication of the pandemic to public. Special care is needed in the realm of social media.
  13. Cross-government efforts need to be conducted to avoid repetition and redundancy across departments.
  14. Department of Education should investigate the impact of school closures on the wider community.
  15. British Nationals residing overseas should be taken into account during an influenza.
  16. Ministry of Defence should be required to assist in the worst case scenario.
  17. The process and timeline of front line responders need to be made more precise.
  18. A framework for analysing social care and surge capacity needs to be established.
  19. The potential for increasing social care real-estate and staff numbers need to be examined.
  20. Strategies to allocate voluntary resources during a pandemic need to be developed with advice from non-health departments.
  21. Excess death management needs review.
  22. Pandemic contingency plans and procedures as a whole require more development.