In Imperial College’s March 16th paper, Professor Ferguson and his team admit that the suppression strategy will only be effective if it’s kept in place until a vaccine becomes available, which they estimate will be in 18 months:
The major challenge of suppression is that this type of intensive intervention package – or something equivalently effective at reducing transmission – will need to be maintained until a vaccine becomes available (potentially 18 months or more) – given that we predict that transmission will quickly rebound if interventions are relaxed.
The most we can hope for before a vaccine becomes available, apparently, is what they call “intermittent social distancing”, i.e. relaxing suppression measures temporarily in relative short time windows, then reimposing them when case numbers start creeping up again.
Maintaining the lockdown for 18 months is bad enough, but what if a vaccine isn’t available by September 30th 2021? Eleven years after the H1N1 influenza pandemic (swine flu), there are still no antiviral therapies that have been shown to save lives. If the time horizon for developing a vaccine is much longer than a year-and-a-half, the choice we face is not between switching to mitigation or keeping the lockdown in place until 30th September 2021, as Professor Ferguson recommends. The choice is between switching to mitigation or maintaining the lockdown indefinitely. Since the latter isn’t economically viable, in all likelihood we’re going to have to abandon the lockdown before a vaccine has been developed, at which point all the gains we’ve made in terms of saved lives will be lost. Okay, perhaps not all since we may increase the critical care capacity of the NHS as we buy time, but even Professor Ferguson isn’t optimistic about that. Logically, therefore, it makes sense to abandon the suppression strategy now, rather than continue to rack up economic costs for which there’ll be few benefits.
Further Reading
‘Quest For a Pandemic Pill‘ by Matthew Hutson, The New Yorker, April 6th 2020
‘Global race for coronavirus vaccine could turn into a marathon‘ by Tony Allen-Mills and Andrew Gregory, The Sunday Times, April 12th 2020
‘Coronavirus: Vaccine could be ready as early as September, according to scientist‘, Sky News, April 12th 2020
‘Don’t bank on a coronavirus vaccine, says Sir Patrick Vallance‘ by Ryhs Blakely, The Times, April 20th 2020