17 May 2020
Epidemiologist Simon Thornley says is likely that there will be a rise in COVID-19 cases in New Zealand, so while there is no need to return to national lockdown, protection of vulnerable people is necessary.
“Internationally lockdowns have not prevented subsequent spikes in the number of cases, such as in Hokkaido, Japan. Lockdowns just slow or delay the inevitable resurgence of COVID-19.
“While the evidence does not endorse further lockdowns, even in the face of further cases, the elderly deserve protection. The rest of us can safely get on with our lives.
“I expect COVID-19 to join other coronaviruses such as HCoV-229E, HCoV-HKU1 and HCoV-OC43 as endemic with winter seasonal peaks – when they cause fatalities in rest homes. So, we need to take particular care toward older people and those with co-morbidities.
Thornley says that to justify a renewed lockdown the Government would need to argue health services were at risk, public immunity was low, and the risk to people’s health was major.
“The nation may lack immunity due to lockdown – but we have no information because the Government hasn’t done serology tests. But we do appear to have enough health service capacity, and for most of us the virus poses very little danger.”
There is now compelling evidence that lockdowns in Europe were not especially effective, and that there was no difference in per capital cases and deaths in a comparison of US States. The main factor linked to cases and deaths has been found to be testing rates; the more tests that were carried out by State, the more cases were found.
The risk of future waves is related to our exposure to the virus. Tests of immunity in hard hit countries are returning immunity levels of about 5%, such as in Spain. Other tests of cell mediated immunity suggest higher real levels of immunity than those obtained from antibody tests alone. In Germany, 34% of antibody negative healthy donors showed markers of cellular immunity. The rise, fall and now low number of cases in China, with smaller contained outbreaks after the initial peak, suggest that immunity is sustained, at least in the medium term.
In even hard hit countries the risk of death from the virus for the majority of working age people, especially those under the age of forty, the mortality risk is very low.
Contact: Simon Thornley, 021 299 1752