Hope is growing two ongoing flu studies can be expanded to find the true number of COVID-19 cases in New Zealand.
The Institute of Environmental Science and Research (ESR) is currently taking swabs and blood samples from participants to study flu, and how the body's immune system responds to it. Now they've got ethics approval to also test for COVID-19.
"Flu virus is a respiratory virus, and COVID-19 is also a respiratory virus," principal investigator Sue Huang told Newshub. "They follow similar kinds of symptoms."
But they can have very different outcomes, with COVID-19's mortality rate potentially magnitudes larger than that of the flu. There are also anecdotal reports of the virus which causes COVID-19 reactivating in recovered patients, and fears it may have long-term effects in those who survive.
"We'll test a very comprehensive range - T-cells, B-cells... antibodies, trying to understand what are those immunological determinants, why older people are more prone to having severe COVID-19 infections, why young children are quite mild, if they have an infection," said Dr Huang.
The virus has spread quickly across the world as it is more contagious than the flu and no one, prior to recovery, has any immunity to it.
The expanded studies won't just help find potential vaccines and treatments for COVID-19, but also help determine how many Kiwis actually have the disease. While the official count is 1386, that only includes people who have been tested - people carrying the virus without symptoms, or only mild infections, are unlikely to have been tested, but they can still spread the disease.
The studies will now not follow just individual participants, but their households too.
"The household is a valuable setting to understand the chain of transmission, the clinical spectrum of illness and the amount and duration of virus being shed from infected individuals," said Dr Huang.
Getting a truer picture of the virus' spread will be vital in coming weeks.
"Those proportions of immunity and infectability is very important for public health officials to tailor a public health response."
One study, SHIVERS-II, is following a couple of thousand adults in Wellington, and the other, WellKiwis, children from birth to age seven.
