Boris Johnson may meet Donald Trump face to face at the G7 summit in the US next month, after Downing Street said it was still exploring the arrangements for the event.
The meeting of global leaders is scheduled for 10 June, with Trump saying he would like it to be held at Camp David, the president’s rural estate.
Epidemics of infectious diseases behave in different ways but the 1918 influenza pandemic that killed more than 50 million people is regarded as a key example of a pandemic that occurred in multiple waves, with the latter more severe than the first. It has been replicated – albeit more mildly – in subsequent flu pandemics.
How and why multiple-wave outbreaks occur, and how subsequent waves of infection can be prevented, has become a staple of epidemiological modelling studies and pandemic preparation, which have looked at everything from social behaviour and health policy to vaccination and the buildup of community immunity, also known as herd immunity.
Is there evidence of coronavirus coming back in a second wave?
This is being watched very carefully. Without a vaccine, and with no widespread immunity to the new disease, one alarm is being sounded by the experience of Singapore, which has seen a sudden resurgence in infections despite being lauded for its early handling of the outbreak.
Although Singapore instituted a strong contact tracing system for its general population, the disease re-emerged in cramped dormitory accommodation used by thousands of foreign workers with inadequate hygiene facilities and shared canteens.
Singapore’s experience, although very specific, has demonstrated the ability of the disease to come back strongly in places where people are in close proximity and its ability to exploit any weakness in public health regimes set up to counter it.
What are experts worried about?
Conventional wisdom among scientists suggests second waves of resistant infections occur after the capacity for treatment and isolation becomes exhausted. In this case the concern is that the social and political consensus supporting lockdowns is being overtaken by public frustration and the urgent need to reopen economies.
The threat declines when susceptibility of the population to the disease falls below a certain threshold or when widespread vaccination becomes available.
In general terms the ratio of susceptible and immune individuals in a population at the end of one wave determines the potential magnitude of a subsequent wave. The worry right now is that with a vaccine still months away, and the real rate of infection only being guessed at, populations worldwide remain highly vulnerable to both resurgence and subsequent waves.
He tweeted that hosting it face to face would be a signal to the world of “normalisation” amid the coronavirus pandemic and that other countries involved in the summit were starting to make their own “comeback”.
The UK prime minister’s spokesperson said: “We are in close contact with the White House about the summit and we will look at the details of what they are proposing.”
A physical summit was cancelled in March with the intention of it being transferred to video conferencing.
The Canadian prime minister, Justin Trudeau, said he would consider the summit proposals but discussions were ongoing. The French president, Emmanuel Macron, said he was open to attending.
The state of Maryland, which is home to Camp David, issued an executive order in April that residents should wear face masks in public settings.
Trump and the US vice-president, Mike Pence, have been criticised for appearing in public without masks, despite health officials encouraging Americans to wear them.
Asked if Johnson would attend the event and wear a mask, the prime minister’s spokesperson said: “[Those] arrangements are a matter for the home country.”
The government plans to release more details on Friday of the 14-day quarantine proposals for UK arrivals, which include some exemptions.
When asked whether Johnson’s potential trip to the US would incur a two-week quarantine period on his return, his spokesman said: “You’ll see the list of exemptions later on, but the prime minister would follow the guidelines.”
By hosting the event in person, Trump has raised questions over whether the typically large delegations that accompany leaders to the G7 would be attending, what physical distancing measures would be in place and how journalists from around the world would report on the summit.
Trump had intended to focus the G7 meeting on the economy, eschewing the more traditional subject of climate change.
Earlier this year he had planned to host the talks in Miami, at his Trump National Doral golf resort, however this was switched to Camp David, where the president has spent several weekends during the coronavirus pandemic.