Published On Aug 18, 2020
New Zealand
Ruled out
Frozen food items or freight
Burning ember
Infection from returners
https://www.health.govt.nz/our-work/d...
Cases, + 13 + 7 + 13 + 9 + 12 = 1643
Hospitalised, + 1 = 6
Long term immunity
It would be good if,
Antibodies provide “real-world” protection
Cellular immunity is long-lasting
Memory B and T lymphocytes
T helpers, suppressors, killers (cytotoxic)
Even in mild cases.
New Delhi 24%
Mumbai 24%
Moscow 21.7 %
Stockholm 10 %
New York 6.9 %
London 17.5 %
UK 6.2 %
Marion Pepper, immunologist, University of Washington
This is exactly what you would hope for
All the pieces are there to have a totally protective immune response
Smita Iyer, immunologist, University of California, Davis
This is very promising
This calls for some optimism about herd immunity, and potentially a vaccine
Professor Danny Altmann, Department of Immunology and Inflammation, Hammersmith Hospital, Imperial College
While this is a small study, it offers a remarkable, real-life, human experiment at a time when we've been short of hard-line, formal, proof that neutralising antibodies genuinely offer protection from re-infection
In short, it’s good news
https://www.telegraph.co.uk/global-he...
Neutralizing antibodies correlate with protection from SARS-CoV-2 in humans during a fishery vessel outbreak with high attack rate
https://www.medrxiv.org/content/10.11...
University of Washington IRB
Identification of immunological correlates would help research
Only animal models to date
Outbreak of SARS-CoV-2 on a fishing boat
Attack rate on board of 85.2% (104/122 individuals)
Predeparture serological and viral RT-PCR testing
Repeat testing after return to shore
Full data on 120 of the 122 crew (9 women)
18 day trip, crew member required hospitalization
Median follow-up of 32.5 days
104 individuals had a positive antigen test or seroconverted during the follow-up period
101 developed IgG antibodies within 50 days
Also
Three crew members seropositive prior to the boat's departure
None of these crew members with antibodies developed symptoms or tested antigen positive
Lab studies also showed their antibodies had neutralising activity
Presence of neutralizing antibodies from prior infection was significantly associated with protection against re-infection (p=0.002).
Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19
Center for Infectious Medicine, Stockholm
https://www.biorxiv.org/content/10.11...
Virus-specific memory T cells have been shown to persist for many years after infection with SARS-CoV-1
Acute phase SARS-CoV-2-specific T cells display high cytotoxic activity
Correlated with various clinical markers of disease severity
SARS-CoV-2-specific T cells were detectable in antibody-seronegative family members
and individuals with a history of asymptomatic or mild COVID-19
Collective dataset shows that SARS-CoV-2 elicits robust memory T cell responses
akin to those observed in the context of successful vaccines
natural exposure or infection may prevent recurrent episodes of severe COVID-19 also in seronegative individuals.
SARS-CoV-2 induces robust memory T cell responses in antibody-seronegative and antibody-seropositive individuals with asymptomatic or mild COVID-19.
Functional SARS-CoV-2-specific immune memory persists after mild COVID-19
https://www.medrxiv.org/content/10.11...
Study was approved by the University of Washington Institutional Review Board
The recently emerged SARS-CoV-2 virus is currently causing a global pandemic and cases continue to rise.
The majority of infected individuals experience mildly symptomatic disease
but it is unknown whether this can induce persistent immune memory that might contribute to herd immunity
Longitudinal assessment
Individuals recovered from mildly symptomatic COVID-19
To determine if they develop and sustain immunological memory
Recovered individuals developed SARS-CoV-2-specific IgG antibody
As well as virus-specific memory B and T cells
In some cases increased numerically over three months following symptom onset
Memory lymphocytes exhibited characteristics associated with potent antiviral immunity
Memory T cells secreted IFN-γ (interferon Gama) and expanded upon antigen re-encounter
Memory B cells expressed specific antibodies