Social Media is both a boon and a bane. Once in a while, rumours do grip handles even as mongering may add and subtract from the original content. A classic example being, the Danish study which concluded that vaccines do not adversely impact immune system. What, however, did do the rounds about the report was the shots are “completely ineffective against the Omicron variant and do interfere with the immune system.”
A recent fact-check undertaken by Reuters traces the basis of the misinterpretation to “vaccine effectiveness (VE) estimates published in one table within the research.”
VE is a measure of the extent to which a vaccine prevents infection. If a VE estimate is 90 percent, it implies that the vaccine prevented 9 out of 10 infections that would otherwise have occurred, according to Dr Christian Hansen, one of the preprint study’s co-authors.
The preprint estimates of VE for the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines has been filed after analysing data from Danish databases between Nov 20 and Dec 12, 2021. The estimates in the study are based on a comparison of infection rates between vaccinated and unvaccinated people in Denmark during the days after the Omicron variant was first detected in the country.
Users have shared a screenshot of a table on page 6 of the preprint (a study that has yet to be peer-reviewed) with claims that the data is proof that vaccines cause harm to immune systems. The table shows the number of cases recorded of Omicron or Delta with VE estimates listed according to the time since second vaccine dose.
VE against Omicron was estimated at 55.2% (14 cases) and 86.7% against Delta (171 cases) between 1 and 30 days after second Pfizer-BioNTech vaccine while VE against Omicron was 36.7% (4 cases) and 88.2% against Delta (29 cases) following Moderna second dose.
VE against Omicron was 76.5% (2,851 cases) and 53.8% against Delta (34,947 cases) after the second Pfizer-BioNTech vaccine dose with VE against Omicron at 39.3% (393 cases) and 65.0% (3,459 cases) following second Moderna vaccine.
The study did not analyse data for severity of disease between unvaccinated, double-vaccinated and boosted groups.
Users online claimed that the table on page 6, particularly negative VE estimates against Omicron 91 to 150 days following second mRNA dose, was proof that vaccines were harming immune systems with other claims that unvaccinated people were less likely to get infected with the virus.