EPIDEMIOLOGISTS and other experts are currently racking their brains on what the results of antibody studies really tell about the coronavirus epidemic, says Mika Salminen, the head of health security at the Finnish Institute for Health and Welfare (THL).
Studies in Spain and Sweden suggest a smaller-than-expected share of the population – only 5–7 per cent – has developed antibodies against the virus, denting hopes that herd immunity would protect the countries from a second wave.
“This is something that’s presently being mulled over by many – what do these antibody tests really tell us,” said Salminen.
Number of coronavirus patients in hospital care continues to drop
Salminen on Thursday said in a press conference that one of the problems is that the immune mechanisms associated with the virus are not known particularly well. It remains unknown, for example, how strong an immunity an infection creates and how long it will protect people from the virus.
The immune response of humans, however, does not necessarily involve antibodies.
“There’s another part of our immune response that’s called cell-mediated immunity. Studying that is much harder,” he reminded. “This complicates these interpretations quite a bit. The fact that people are getting better is of course an indication that the immune response is working. Otherwise they wouldn’t get better.”
This uncertainty also makes it difficult to forecast what lies ahead in the autumn.
“It depends on how the virus behaves. If it behaves like other coronaviruses, there’s a risk of another wave. It remains to be seen whether it behaves differently,” commented Salminen.
He warned that the epidemic may gain momentum also during the summer. “We definitely have to prepare for the eventuality that a second wave takes place sometime in the autumn or early winter. When will it come, that’s hard to predict. We also have to prepare for setbacks in the summer. That’s why it’s important that we keep at these safety measures.”
The epidemic situation is relatively stable in Finland: The reproduction number (R0) of the virus is currently estimated at 0.75–0.85. The number of new cases entered weekly to the infectious disease register has decreased noticeably for more than a month. No new infections were reported by as many as nine hospital districts, as well as the region of Åland, between 18 and 24 May.
Aleksi Teivainen – HT
Source: Uusi Suomi