select search filters
briefings
roundups & rapid reactions
before the headlines
Fiona fox's blog
The Health Secretary Sajid Javid announced to the commons today that from the 16 August, those who are double-jabbed and those under the age of 18 will not have to self-isolate if they are a close contact of someone who tests positive for COVID-19.
Prof Sheila Bird, Formerly Programme Leader, MRC Biostatistics Unit, University of Cambridge, said:
“From 16 August 2021, those of us who are identified by NHS Test & Trace as both close contact of an index case and doubly-vaccinated will not need to self-isolate if a) living in the same household as the index case or b) being an external close contact of the index case.
“Prior to 16 August, NHS Test & Trace needs to publish evidence on the ct-value distribution for close contacts of types a) & b) who sought a PCR-test soon after being asked to self-isolate in April, May or June and whose PCR-test was positive. The public needs to see these distributions separately for PCR-tested close contacts who were i) single-dose vaccinated; ii) doubly vaccinated; iii) unvaccinated and a) aged under 18 years; b) 18-49 years; c) aged 50-69 years; d) aged 70+ years. In all, 12 subgroups of close contacts in each of three months.
“NHS Test & Trace needs, please, to be transparent about the current evidence-base that underlies the planned policy-change which takes effect from 16 August 2021.
Dr Jonathan Stoye, Group Leader, Retrovirus-Host Interactions Laboratory, The Francis Crick Institute, said:
“Given an acceptance of the rationale for releasing lockdown there is one aspect of the Health Secretary’s announcement that I find somewhat perplexing. The logic behind waiting until August 16th for a relaxation of isolation requirements for potentially exposed people who are already fully vaccinated is unclear. It seems unlikely the probability of infection for someone who has had two jabs and a negative PCR test will change between now and then. So, why wait six weeks for this step for such individuals?”
Prof Keith Neal, Emeritus Professor of the Epidemiology of Infectious Diseases, University of Nottingham, said:
“In most of Europe and the USA fully vaccinated do not need to isolate after being a contact unless they have symptoms.
“The recommendation of a PCR test if you are a contact is not recommended in these other countries.
“Vaccination is highly effective at stopping infection and in stopping transmission should become infected including the delta variant.
“This does not mean that people do not need to be careful and I will continue to wear a mask
“A wider health issue is the large numbers of fully vaccinated NHS staff off work as they are isolating. These staff get tested regularly.
“The numbers of staff isolating will be having a knock on effects on care for cancer and other serious conditions.
“The big question is why not implement the change now; the science won’t change in the next 41 days. Other countries having been doing this for months.
“Everyone over 18 has had the opportunity to get their first vaccine. The very few with contraindications can have an equivalent certificate just as is done for yellow fever certificates.”
Dr Peter English, Retired Consultant in Communicable Disease Control, Former Editor of Vaccines in Practice, Immediate past Chair of the BMA Public Health Medicine Committee, said:
“People are asked to self-isolate when they are at high risk of having been infected. People can be infectious before the onset of symptoms, with very mild symptoms, or with no symptoms at all.
“People who are fully vaccinated are less likely to have symptomatic disease, and still less likely to have severe disease, requiring hospital admission. Vaccines are increasingly effective at preventing increasingly severe illness.
“Vaccines are less good at preventing less severe illness.
“People with less severe infection may have lower levels of virus in their respiratory droplets; but this will not always be the case. And they are more likely to continue living normal lives, having contact with and potentially infecting many people (as we saw with Steve Walsh, one of the first UK cases, and one that I was involved in investigating and managing).
“The delta variant which is prevalent in the UK now is more infectious than previous variants, and we do not know how effective vaccines are at reducing infectiousness in people infected with it.
“People who have been fully vaccinated (or who were primed by infection and vaccinated at least 6 weeks later) are less likely to be infected with SARS-CoV-2; and if infected they may be less likely to be infectious. But some of them will be infected, and will be infectious: on average they are a lower infection risk than unvaccinated people. We are not yet in a position to quantify how much lower the risk is.
“So the decision that people who are fully vaccinated need not self-isolate is a gamble. Some preventable transmission will occur as a result; but we can’t yet say how much.”
Video via Sky News – https://news.sky.com/video/covid-sajid-javid-announces-new-self-isolation-rules-12350045
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
Declared interests
Prof Sheila Bird: “SMB is a member of the Royal Statistical Society’s COVID-19 Taskforce; chairs the RSS/DHSC Panel on NHS Test & Trace; and is a member of the RSS Working Group on Diagnostic Tests which reported on 9 June 2021.”
None others received.