Coronavirus: herd immunity may prove to be best path

Sweden’s herd immunity approach to coronavirus may show results later in the year, the head of a government inquiry says.

Sweden's Prime Minister Stefan Lofven last week. Picture: AFP

Sweden’s herd immunity app­roach to the coronavirus may show good results later in the year, the head of a Swedish government ­inquiry claims, as Melbourne grapples with another lockdown after a spike in cases.

Scientists believe the relaxed Swedish approach encouraging social distancing and refusing to impose any sort of lockdown may have already achieved herd immunity after a surge in the number of deaths in April and May, most of whom were in their 80s and 90s in nursing homes.

But getting to this point has been sharp and painful. The country suffered 5420 deaths, equating to 537 deaths per million of population, far in excess of its Scandinavian neighbours who implemented a lockdown. About 90,000 Swedes die each year.

Data from Statistics Sweden shows that in April and May, deaths were higher than the past five-year average and the highest since 2001, yet the year overall so far has been on par with previous death tallies. Interestingly, the same is borne out in locked-down Denmark. Fewer deaths than the average in January to March in Denmark have countered a coronavirus spike in April and May.

Mats Melin, the judge appointed by the government of Prime Minister Stefan Lofven to head the Swedish inquiry, will first look at why nursing home deaths were so high.

“It can hardly be ruled out that what happens later this summer and coming autumn, both at home and in other countries, may come to shed new light on things,’’ Judge Melin said.

Australia, with 104 deaths, has one of the best outcomes so far, with four deaths per million of population. About 160,000 people die in Australia each year.

Australians are still highly vulnerable to the virus. Scientists are still unsure but believe the coronavirus thrives in colder weather

Recent studies in Germany and Sweden show the importance of T-cell immunity — exposure to previous colds and influenza — that offers a form of natural defence against COVID-19.

The current thinking is that herd immunity might be achieved with just 20 per cent of the population infected.

One German study, still to be peer-reviewed, shows 81 per cent of the population may have T-cell resistance to COVID-19.

Oxford University professor Sunatra Gupta created controversy when she told The Weekend Australian that Australia should follow Sweden’s model but heavily protect the elderly and vulnerable.

Her approach is to throw a shield around the vulnerable as the virus will eventually wind its way through the community, leaving the vast majority of people unaffected. The impact will be quicker but without the psychological and economic consequences of lockdowns.

“If Sweden locked down as well, I am sure in the next wave there would have been many more deaths,” she said.

“The criticism of Sweden at this point is completely out of order.’’

The government-funded Swe­dish Defence Research Agency last week published a report detailing shortcomings in Sweden’s ability to respond to the crisis.

The report’s researchers found that Swedish authorities had not been prepared for the crisis ­despite several “warning shots”, including the spread of SARS in 2002, the avian flu in 2006 and the swine flu in 2009.