The percentage of people who now have antibodies for the new coronavirus Covid-19 stands at 6%, twice as high as the last time tests were done.
The latest result comes from tests on 3,400 blood samples from people of all aged. And while the increase in immunity is encouraging, it also means that group immunity is still a long way off, experts said.
“Group immunity will not be the answer,” said epidemiologist Pierre Van Damme, speaking on the VRT current affairs programme De Afspraak. “The whole of Europe is convinced of that. It will have to be done in a different way.”
Although an increase was seen in all age groups, two in particular stood out.
“Those were the age groups of 20 to 30-year-olds, and 80 to 90-year-olds,” he said. “The 20 to 30-year-olds are interesting. That measurement was carried out on blood samples taken between 20 and 26 April. Those antibodies have to originate from an exposure about three weeks earlier, which brings us to the Easter holidays. That illustrates how the virus spreads among the population.”
The samples studied were not from Covid-19 patients, he pointed out, who would have been seen at a triage centre or a hospital. Instead, the 3,400 samples studied were all taken at a GP’s surgery.
The next series of tests, due to be carried out in three and six weeks, will give an indication of the effects of the latest relaxation of some of the lockdown measures, which start on Monday 11 and again on Monday 18.
“In the next tests we will see the impact of the relaxation of the corona measures. It will be interesting if there is another three or four percent increase. If the increase in the spread is constant, that would be fantastic. That will be an incentive for every citizen in the country, and show that we are doing well.”
However the increase in the rate of developing antibodies means that the much sought-after group immunity – where there are so many people immune to the virus that it has little or no opportunity of spreading – is still a long way off.
Experts generally reckon that it would take a minimum of 70% of people with antibodies before group immunity is present. At a rate of 3% every three weeks, that target would only be attained in late July 2021.