April 27, 2020

COVID-19: Global death toll surpasses 200,000; No evidence recovered patients are protected from a second infection

ECDC case count update

According to the European Centre for Disease Prevention and Control (ECDC), since 31 December 2019 and as of 27 April 2020, 2 914 507 cases of COVID-19 have been reported, including 205 923 deaths.

Cases have been reported from:

Africa: 31 748 cases; the five countries reporting most cases are South Africa (4 546), Egypt (4 319), Morocco (4 065), Algeria (3 382) and Cameroon (1 621).

Asia: 467 957 cases; the five countries reporting most cases are Turkey (110 130), Iran (90 481), China (84 199), India (27 892) and Saudi Arabia (17 522).

America: 1 182 433 cases; the five countries reporting most cases are United States (965 910), Brazil (61 888), Canada (46 884), Peru (27 517) and Ecuador (22 719).

Europe: 1 223 581 cases; the five countries reporting most cases are Spain (207 634), Italy (197 675), Germany (155 193), United Kingdom (152 840) and France (124 575).

Oceania: 8 092 cases; the five countries reporting most cases are Australia (6 713), New Zealand (1 122), Guam (142), French Polynesia (57) and Fiji (18).

Other: 696 cases have been reported from an international conveyance in Japan.

Deaths have been reported from:

Africa: 1 415 deaths; the five countries reporting most deaths are Algeria (425), Egypt (307), Morocco (161), South Africa (87) and Cameroon (56).

Asia: 17 164 deaths; the five countries reporting most deaths are Iran (5 710), China (4 639), Turkey (2 805), India (872) and Indonesia (743).

America: 65 752 deaths; the five countries reporting most deaths are United States (54 876), Brazil (4 205), Canada (2 560), Mexico (1 351) and Peru (728).

Europe: 121 476 deaths; the five countries reporting most deaths are Italy (26 644), Spain (23 190), France (22 856), United Kingdom (20 732) and Belgium (7 094).

Oceania: 109 deaths; the five countries reporting most deaths are Australia (83), New Zealand (19), Guam (5), Northern Mariana Islands (2) and Fiji (0).

Other: 7 deaths have been reported from an international conveyance in Japan.

Antibodies in people who have recovered from COVID-19

According to a Scientific Brief published by WHO on April 24, there is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.

The Scientific Brief noted that WHO continues to review the evidence on antibody responses to SARS-CoV-2 infection. It said most of these studies show that people who have recovered from infection have antibodies to the virus. However, some of these people have very low levels of neutralizing antibodies in their blood, suggesting that cellular immunity may also be critical for recovery. As of 24 April 2020, no study has evaluated whether the presence of antibodies to SARS-CoV-2 confers immunity to subsequent infection by this virus in humans.

The report added that laboratory tests that detect antibodies to SARS-CoV-2 in people, including rapid immunodiagnostic tests, need further validation to determine their accuracy and reliability. Inaccurate immunodiagnostic tests may falsely categorize people in two ways:

  • They may falsely label people who have been infected as negative.
  • People who have not been infected are falsely labelled as positive.

"Both errors have serious consequences and will affect control efforts", the Scientific Brief warned.

In addition, the report added that these tests need to accurately distinguish between past infections from SARS-CoV-2 and those caused by the known set of six human coronaviruses - four of these viruses cause the common cold and circulate widely; the remaining two are the viruses that cause Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome. People infected by any one of these viruses may produce antibodies that cross-react with antibodies produced in response to infection with SARS-CoV-2.

"Many countries are now testing for SARS-CoV-2 antibodies at the population level or in specific groups, such as health workers, close contacts of known cases, or within households", the Scientific Brief noted.

The Scientific Brief also stated that WHO supports these studies, as they are critical for understanding the extent of – and risk factors associated with – infection. "These studies will provide data on the percentage of people with detectable COVID-19 antibodies, but most are not designed to determine whether those people are immune to secondary infections", it noted. 

At this point in the pandemic, according to the Scientific Brief, there is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an “immunity passport” or “risk-free certificate”.

"People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice. The use of such certificates may therefore increase the risks of continued transmission", the report added.

WHO noted that the Scientific Brief will be updated as new evidence becomes available.

SOURCE: ECDC; WHO