A sub-cohort of Virus Watch participated in monthly at-home capillary blood sampling to test for antibodies to SARS-CoV-2. Anti-spike and nucleocapsid antibody titers were measured using Elecsys anti-spike and -nucleocapsid electro-chemiluminescent immunoassays. 

A breakthrough infection was defined as a positive SARS-CoV-2 test in double-vaccinated individuals occurring at least 14 days after the second vaccination. First, antibody waning was estimated by comparing anti-spike antibody levels in ChAdOx1 and BNT162b2 recipients by sex, age, clinical vulnerability, and time since vaccination.

Nearly 25,000 samples from more than 9400 individuals were included in the analysis of anti-spike antibody decay; most people (5960) received a second dose of ChAdOx1, and 3490 received BNT162b2, and 2% of the cohort received different first and second doses. 

The study found that anti-spike antibody levels peaked after three- or four weeks post-administration of the second dose, with the geometric mean being nine-fold higher for BNT162b2 than ChAdOx1. A substantial waning of anti-spike levels was evident after administering either vaccine. Notably, higher anti-spike levels were associated with a lower risk of vaccine breakthrough infection.

The team included 9244 subjects in the analysis of the effect of anti-spike antibody levels on SARS-CoV-2 infection risk. There was no association between second dose vaccine type and anti-spike levels. Overall, the antibody waning analysis findings suggested that ChAdOx1 recipients were at an elevated risk of breakthrough infection. This was further confirmed by the test-negative case-control analysis, which revealed that recipients of two ChAdOx1 doses had 1.64 increased odds of breakthrough infection relative to double-vaccinated BNT162b2 recipients.  

This work has been reported on here: 

https://www.news-medical.net/news/20220823/What-are-the-effects-of-anti-spike-antibody-levels-on-SARS-CoV-2-infection-risk.aspx

For a link to the full article please see: https://www.nature.com/articles/s41467-022-32265-5

This study hypothesized and evaluated the use of spectacles in a community context for minimizing the likelihood of COVID-19. 

Among the 58,670 volunteers of the Virus Watch cohort, the researchers invited 31,749 participants to answer a monthly survey about contact lenses and spectacle use, and 19,166 responded to this questionnaire. The questionnaire covered topics including purpose, frequency of use, and probability of using a face mask with spectacles.

While 22.99% of people who never wore spectacles for general use had COVID-19, only 15.63% of those who constantly wore spectacles for regular use were SARS-CoV-2-infected. The multivariate regression model controlled for gender, income, age, and occupation and depicted a 15% lower chance of COVID-19 for individuals who reported wearing spectacles constantly for general usage than people who had never worn spectacles. A similar observation was found in those using spectacles always for reading and other particular activities.

The study findings demonstrated that individuals who use spectacles had a lower chance of SARS-CoV-2 infection than non-spectacle users. However, the protective effect against COVID-19 was not observed in contact lens users. 

Overall, the present research indicates the relevance of the eye as a portal for SARS-CoV-2 infection. The authors found a moderate decline in the chance of COVID-19 in individuals who wore spectacles. This research extrapolated the existing evidence of the SARS-CoV-2 infection through the eyes in the hospital setting to a community context. 

This work has been reported on here:

https://www.news-medical.net/news/20220407/Study-finds-a-significant-reduction-in-the-risk-of-COVID-19-infection-among-those-who-always-wear-glasses.aspx

For a link to the full article please see: https://www.medrxiv.org/content/10.1101/2022.03.29.22272997v1 

It is poorly understood which workers lack access to sick pay in England and Wales. This evidence gap has been of particular interest in the context of the Covid-19 epidemic given the relationship between presenteeism and infectious disease transmission.

Using a Virus Watch study sub-cohort of 8,874 workers, we found stark inequalities in access to paid sick leave among workers in England and Wales. Older workers, workers from certain minority ethnic backgrounds, workers in low-income households and those in working class occupations are more likely to lack access to paid sick leave.

Policymakers should consider expanding access to sick pay to mitigate transmission of Covid-19 and other infectious disease epidemics in the community as we ‘learn to live with Covid’.

This work has been extensively reported by the media:

Online: The Guardian, The Morning Star, Working Wise, People Management, HR Review, London News Time, The Big Issue 

Broadcast: Sky News, Times Radio, GB News, syndicated to LBC 

Print coverage: The Guardian (editorial p2); Yorkshire Post (p4); The Metro (London), Lancashire Evening Post, Blackpool Gazette, Newcastle Evening Chronicle, The Courier, Belfast Newsletter, Big Issue

Political: SNP work and pensions spokesperson calls on government to improve sick pay after ‘damning report from IPPR’; press response from Unison chief executive; press response from USDAW union; response from TUC; response shadow DWP minister Jon Ashworth; Labour’s Andy McDonald shares IPPR’s tweet

For a link to the full article please see:

https://www.medrxiv.org/content/10.1101/2022.01.30.22270112v1

The Omicron variant has increased SARs-CoV-2 infections in double vaccinated individuals globally. People that had received a double dose of the Oxford/AstraZeneca vaccine, had a 35% (95%CI: 15% – 58%) increase in SARs-CoV-2 infections when compared to people that received two doses of BioNTech/Pfizer. To tackle rising infections, the UK accelerated booster vaccination programmes used mRNA vaccines (BioNTech/Pfizer & Moderna) irrespective of an individual’s first two vaccine types.

We analysed a total of 19,692 participants who received their booster vaccination between September 16th 2021 and January 5th 2022.

After adjusting for age, sex, clinical vulnerability status, and socioeconomic status, we found no difference between the risk of infection of SARs-CoV-2 between those who received different COVID-19 vaccines as their primary course in addition to an mRNA-based booster vaccine.

Our findings demonstrate the importance of booster (third) doses to maintain protection and suggest that these should be prioritised to those who received Oxford/AstraZeneca as their primary course.

This work has been reported on here:

https://www.news-medical.net/news/20220208/Study-highlight-benefit-of-mRNA-boosters-for-SARS-CoV-2-following-different-initial-vaccine-types.aspx

For a link to the full article please see:

https://www.medrxiv.org/content/10.1101/2022.02.04.22270479v1

In the early stages of the pandemic, it was thought that antibodies produced post-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provide a certain degree of protection against reinfection for at least six months.

COVID-19 vaccines only stimulate anti-S antibodies. Measurement of both anti-S and anti-N antibodies is required to distinguish antibodies derived from natural infection and vaccination.

This study investigated anti-S and anti-N trends in individuals with antibody results from 1 to 540 days since PCR confirmed infection. Researchers observed that approximately 4 out of 5 individuals were seropositive for anti-N at any point between 0 to 269 days after testing positive for COVID-19. 35-49-year-olds showed higher odds of a positive anti-N result than individuals aged 18 and 34 years.

Scientists stated that antibody positivity could be influenced by the viral load during infection. The data presented here are from a community cohort study, which means that the symptom profiles could be less severe among the participants when contrasted with hospital-based longitudinal studies.

Individuals aged 18-49 years had an earlier peak and antibody waning. Anti-N positivity was observed longer in older people who had significantly more comorbidities and, therefore, had a higher likelihood of experiencing the severe disease.

The proportion of seropositive anti-N samples was 42.6% between days 0-29. This increased to 80% from day 30 onwards. These numbers are lower than other studies that considered hospitalized patients for the study. The difference in anti-N as observed in the data was disaggregated by sex, with earlier peak and waning in females. A meta-analysis showed that men were 2.41 times more at risk of developing severe disease than women.

Scientists concluded that seroprevalence studies on anti-N alone may underestimate the true cumulative incidence of infection. They showed a decline in anti-N levels from 120 days onwards and, therefore, provided new insights into the limitations of seroprevalence studies. As the duration of anti-N positivity is influenced by age and sex, serosurveillance might require shorter time windows of testing post-SARS-CoV-2 infection.

This work has been reported on here: 

https://www.news-medical.net/news/20220204/Observational-analysis-of-nucleocapsid-and-spike-antibody-responses-post-SARS-CoV-2-infection.aspx

For a link to the full article please see: 

https://www.ijidonline.com/article/S1201-9712(22)00449-0/fulltext

Total antibody levels appear to start declining at 2-3 after complete vaccination and can reduce by more than 50% over 10 weeks, according to new data from Virus Watch.

The clinical implications of waning antibody levels are not yet clear, but some decline was expected and current research shows that vaccines remain effective against severe disease. 

The findings, published as a research letter* in The Lancet, include data from over 600 people taking part in Virus Watch.

You can read details of this analysis here:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01642-1/fulltext

This work was reported on by multiple print and online media see links below. 

https://www.ucl.ac.uk/news/2021/jul/vaccine-antibody-levels-start-wane-around-2-3-months

https://www.theguardian.com/world/2021/jul/22/uk-scientists-back-covid-boosters-as-study-finds-post-jab-falls-in-antibodies

https://www.nature.com/articles/d41586-021-02158-6

The Virus Watch study in England and Wales, found that the serial interval of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is broadly similar to estimates from previous studies and there is no evidence that the B.1.1.7 variant first detected in the U.K. (locally known as the Kent Variant) is associated with any change.

Serial interval is an estimation of the spread of the disease and is often measured as the time interval between symptom onset in a primary case and the onset of symptoms in the secondary cases infected by the primary case. Serial interval is an important parameter used in disease transmission models and can help guide control strategies.

Apart from the serial interval, the doubling time of disease also depends on the reproduction number (R). Diseases that have a shorter serial interval but similar R values will have shorter doubling times.

This work has been reported on here:

https://www.news-medical.net/news/20210519/B117-not-associated-with-change-in-serial-interval-of-COVID-19.aspx

For a link to the full article please see:

https://www.medrxiv.org/content/10.1101/2021.05.17.21257223v1