Over half population now have Covid antibodies from vaccination or infection, figures reveal
MORE than half of people in Wales now have antibodies against Covid-19, either through vaccination or infection, according to new figures.
Some 50.5% of people in private households in Wales are likely to have tested positive for the antibodies in the week to March 14, according to the latest estimates from the Office for National Statistics (ONS).
The vast majority of this will be the result of vaccinations, with more than 1.4 million people across Wales having received at least one dose.
The ONS stressed it was important to “draw the distinction between testing positive for antibodies and having immunity”.
But the figure in England – 54.7% – which was broadly in line with that of Wales and also Northern Ireland (49.3%) was yesterday described as “hugely promising” by England’s Health Secretary Matt Hancock.
The presence of coronavirus antibodies suggests someone has either had Covid-19 in the past or has been vaccinated.
It takes between two and three weeks after infection or vaccination for the human body to make enough antibodies to fight Covid-19.
In further positive news yesterday in the fight to tackle coronavirus infections:
■ no cases of a blood clotting disorder have been found in the first 440,000 people vaccinated against Covid-19 in Wales;
■ no new deaths with Covid-19 were reported in Wales in latest official figures; and
■ fewer than 100 new positive cases have been recorded in the latest 24 hours of figures.
The ONS yesterday said: “We’ve published our latest antibody and vaccine data for the UK. We estimate that one in two people or 54.7% of the population in England tested positive for Covid-19 antibodies in the week ending March 14, 2021.
“In Wales, an estimated one in two people, or 50.5% of the population tested positive for Covid-19 antibodies in the week ending March 14, 2021.
“In Northern Ireland, an estimated one in two people, or 49.3% of the population tested positive for Covid-19 antibodies in the week ending March 14, 2021.
“In Scotland, an estimated two in five people, or 42.6% of the population tested positive for Covid-19 antibodies in the week ending March 14, 2021.”
“The data show a reduction in antibody positivity rates among older individuals during the most recent days in the period analysed; this is likely because of people in these prioritised age groups having received their first vaccine dose but not yet their second dose; this does not necessarily mean they have no immunity protection against coronavirus (Covid-19).
“For the first time, we have included modelled estimates of the number of people who have received at least one dose of a vaccine; across all four countries of the UK there is a clear pattern between vaccination and testing positive for Covid-19 antibodies.
“It is important to draw the distinction between testing positive for antibodies and having immunity.
“Following infection or vaccination, antibody levels can vary and sometimes increase but are still below the level identified as ‘positive’ in our test, and other tests.
“This does not mean that a person has no protection against coronavirus (Covid-19) since an immune response does not rely on the presence of antibodies alone.
“We also do not yet know exactly how much antibodies need to rise to give protection. A person’s ‘T cell’ response will provide protection but it is not detected by blood tests for antibodies.”
The figures are for people in private households and do not include settings such as hospitals and care homes.
The figures also show 79.2% of people aged 80 and over in private households in Wales are likely to have Covid19 antibodies. This compares with 86.0% in England and 74.0% in Scotland.
In Northern Ireland, where the ONS instead uses the 70+ age group due to small sample sizes, the figure was 76.4%.
Because care home residents were
also among the priority groups for the vaccine, the true figure for antibodies among those aged 80 and over may be different, the ONS said.
In a separate development, no cases of a blood clotting disorder were found in the first 440,000 people to have been vaccinated against Covid-19 in Wales.
Scientists in Swansea University looked at anonymised patient data between January 1, 2019 and January 31, 2021 to determine whether there had been a rise in cases of venous sinus thromboembolism.
The extremely rare condition was found in a small number of patients in Norway and Germany and was one of the reasons why several European countries decided to temporarily halt the use of the Oxford AstraZeneca vaccine.
However the Medicines and Healthcare products Regulatory Agency (MHRA) said there has been no confirmation the reports of blood clots were caused by the vaccine.
In the 25-month period analysed by the Secure Anonymised Information Linkage (Sail) databank in Swansea University, a total of 19 cases of the disorder were recorded in Welsh patients, but no new cases were recorded in individuals who had received a vaccine in this period.
Seven people with a previous diagnosis of this condition had been vaccinated by January 31, 2021.
Between December 4, 2020 and January 31, 2021, 440,000 people had at least one dose of the vaccine as recorded in the Welsh Covid-19 Vaccine data.
Of these, 180,000 people received the Oxford AstraZeneca vaccine and 260,000 received the Pfizer Vaccine.
Ronan Lyons, professor of public health and director of Sail Databank said: “This is an important finding about the safety of the vaccines in use in Wales. We found no cases of this rare clotting disorder amongst the first 440,000 people who were vaccinated up until the end of January.
“We will continue to interrogate more data as it becomes available and as more people are vaccinated. This is very good news for our collective efforts to emerge from this pandemic and save more lives through the vaccination programme.”
Venous sinus thromboembolism is a condition found in fewer than one person per month in the Welsh population of 3.2 million people.
As it is diagnosed in hospital, there is a delay in detailed coding of records which is why the analysis was completed up until end of January 2021 – but it will be updated going forward.
The findings came as Wales recorded no new coronavirus deaths and fewer than 100 positive cases in the latest 24 hours of figures.
Latest data published by Public Health Wales yesterday reported 94 new positive cases period which brings the total since the outbreak began to 209,285. It is the lowest number of new cases reported in a day since September 5 last year.
According to PHW’s data, the overall number of people to have died in the country within a month of testing positive for the virus remains at 5,506.
But the “true” figure of people who have lost their lives with coronavirus – recorded using a different methodology by the ONS – showed the death toll has now reached 7,764 in Wales, and more than 150,000 across the UK.
The infection rate across Wales is now 37.6 per 100,000 people, based on the seven days up to March 25 – a drop from 38.1 on Monday. Only four parts of Wales now have an infection rate of over 50 cases for every 100,000 people in the last week.
Meanwhile, the percentage of tests coming back with positive results is now 2.7%, way below the key benchmark of 5%.
The latest figures also show that 1,413,710 people have received the first dose of a Covid-19 vaccine and 424,016 have had both doses.
Cardiff was the county with the highest number of new cases confirmed yesterday with 14, followed by Gwynedd with 10, Swansea with nine, and Anglesey, Flintshire, Pembrokeshire and Neath Port Talbot with six each.
Meanwhile Wrexham and Caerphilly had five each, Newport, Conwy and Merthyr Tydfil had four each, Powys had three, Denbighshire, Vale of Glamorgan and Carmarthenshire had two each, and Bridgend, Rhondda Cynon Taf and Ceredigion had one each. Torfaen, Monmouthshire and Blaenau Gwent all recorded no new cases yesterday.