We report on humoral immunity from 2 weeks to 6-months post-vaccination in 120 nursing home residents and 92 ambulatory healthcare worker controls with and without pre-vaccination SARS-CoV-2 infection. Anti-spike, anti-RBD and neutralization levels dropped more than 84% over 6 months’ time in all groups irrespective of prior SARS-CoV-2 infection. At 6 months post-vaccine, 70% of the infection-naive NH residents had neutralization titers at or below the lower limit of detection compared to 16% at 2 weeks after full vaccination.
Anti-spike and anti-receptor binding domain (RBD) IgG, and serum neutralization titers, were assessed using a bead-based ELISA method and pseudovirus neutralization assay.
“..our data suggest that vaccine effectiveness against any symptomatic disease is considerably lower against the delta variant and may wane over time since vaccination.”
** One of the longer-term worries we have had at Coronaheadsup.com is that the virus might decide to somehow target vaccinated people. Let’s hope that this report is not the first evidence of that. Ed.
Between 11th–25th June 2021, 69 healthcare workers were tested positive for SARS-CoV-2. 23 complete genome sequences were obtained. Viral loads of breakthrough Delta variant infection cases were 251 times higher than those of cases infected with old strains detected between March-April 2020.
The 23 complete genome sequences all belonged to the Delta variant, and were phylogenetically distinct from the contemporary Delta variant sequences obtained from community transmission cases, suggestive of ongoing transmission between the workers.
Time from diagnosis to PCR negative was 8–33 days (median: 21). Neutralizing antibody levels after vaccination and at diagnosis of the cases were lower than those in the matched uninfected controls. There was no correlation between vaccine-induced neutralizing antibody levels and viral loads or the development of symptoms.
Interpretation: Breakthrough Delta variant infections are associated with high viral loads, prolonged PCR positivity, and low levels of vaccine-induced neutralizing antibodies, explaining the transmission between the vaccinated people. Physical distancing measures remain critical to reduce SARS-CoV-2 Delta variant transmission.
We describe 3 instances of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission despite medical masks and eye protection, including transmission despite the source person being masked, transmission despite the exposed person being masked, and transmission despite both parties being masked. Whole genome sequencing confirmed perfect homology between source and exposed persons’ viruses in all cases.
In Kanta-Häme hospital epidemic, about 80% of those infected with corona have received at least the first dose of vaccine. The [Delta] variant of the coronavirus has been revealed to be the cause of the hospital epidemic. “The [B.1.617.2 Delta variant] is very easily spread.” says Chief Physician of the Kanta-Häme Hospital District Sally Leskinen. According to Leskinen, it is worrying that the precautions that have stopped the spread of previous virus variants in hospitals have not been effective enough now. “The fact that the surgical mask has been used in all situations and that patients with symptoms of infection have extensive protective equipment is not enough now,” says Leskinen.
The coronavirus epidemic has spread from Hämeenlinna to Kanta-Häme Central Hospital to health center hospitals in Hämeenlinna, Riihimäki and Forssa. There are a total of 80 infected in the chains. Hämeenlinna Central Hospital has two infection chains with a total of more than 50 infections. In addition, Riihimäki Hospital has a chain of 30 infections.
“The virus is easily infected. In those wards where infections occurred before the first cases occurred and the chains of infection were curtailed, 40 percent of patients have become infected,” says Sally Leskinen. Now the spread has been stopped and no new surprising infections have been detected in hospitals. Family members of nursing staff have also become infected, which in turn has caused extensive exposure situations in schools.
The majority of nursing staff have already received two coronary vaccinations, but still in Kanta-Häme, 11 per cent of the staff of the hospital epidemic outpatient department have been infected. About half of the infected nursing staff have had symptoms, some of them more severe.
HS.fi report (in Finnish)
Helsinki Times report (In English)
** UPDATE 3rd August 2021 ** Eurosurveillance report:
“Exposure to SARS-CoV-2 occurred in almost every unit of the central hospital. Some exposed patients had been transferred to four of the six primary care facilities. In three of these four facilities, the outbreak spread through transfers that took place before the outbreak was detected. In the fourth facility, the transfer happened after outbreak detection and the exposed patient was quarantined and there was no further spread.”