UCL Institute of Health Informatics


VIVALDI Publications

The VIVALDI research team publish extensively across wide range of academic journal. Below you will find details of their papers...


Krutikov M, Palmer T,  Tut G, Fuller C, Azmi B, Giddings R, Shrotri M, Kaur N, Sylla P, Lancaster T, Irwin-Singer A, Hayward A, Moss P, Copas A, Shallcross L. (2021) Prevalence and duration of detectable SARS-CoV-2 nucleocapsid antibody in staff and residents of long-term care facilities over the first year of the pandemic (VIVALDI study): prospective cohort study. MedRxiv doi.org/10.1101/2021.09.27.21264166
Available at: https://www.medrxiv.org/content/10.1101/2021.09.27.21264166v1.full-text

This study used results of 9488 SARS-CoV-2 nucleocapsid antibody tests from staff and residents in 201 care homes in England that were taken between June 2020 and April 2021. Nucleocapsid antibodies are commonly used to detect past COVID-19 infection as they are not generated in response to vaccination. Over one quarter of staff and one third of residents had evidence of having survived infection over the first two pandemic waves which is higher than has been seen in the general community-dwelling population.  This high proportion of people with natural immunity who have stronger antibody responses to vaccination may affect vaccine effectiveness as over time these numbers will drop. The study also found that nucleocapsid antibodies became undetectable eight months from initial infection in around half of participants, suggesting that more durable and reliable tests for past infection are needed. 

Tut G, Lancaster T, Krutikov M, Sylla P, Bone D, Kaur N, Spalkova E, Bentley C, Amin U, Jadir A, Hulme S, Butler M, Ayodele M, Bruton R, Shrotri M, Azmi B, Fuller C, Irwin-Singer A, Hayward A, Copas A, Shallcross L, and Moss P. (2021) Profile of humoral and cellular immune responses to single doses of BNT162b2 or ChAdOx1 nCoV-19 vaccines in residents and staff within residential care homes (VIVALDI): an observational study. Lancet Healthy Longev 2021. doi: 10.1016/S2666-7568(21)00168-9
Available at: https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(21)00168-9/fulltext

This study used blood samples from 124 residents and staff of 14 long-term care facilities taking part in the VIVALDI study to investigate immune responses to a single dose of COVID-19 vaccine. They found that those who had been infected before, had stronger antibody responses to one vaccine dose when compared with those who had never had COVID-19 infection. Residents who had never been infected before, had a delayed antibody response to vaccination when compared with residents with past COVID-19 infection. This has implications when planning vaccine schedules and considering who should be prioritised for booster doses.”

Shrotri M, Krutikov M, Palmer T, Giddings R, Azmi B, Subbarao S, Fuller C, Irwin-Singer, A., Davies D, Tut G, LopezBernal J, Moss P, Hayward A, Copas A, and Shallcross L. (2021) Vaccine effectiveness of the first dose of ChAdOx1 nCoV-19 and BNT162b2 against SARS-CoV-2 infection in residents of long-term care facilities in England (VIVALDI): a prospective cohort study. Lancet ID 2021 doi.org/10.1016/S1473-3099(21)00289-9
Available at: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00289-9/fulltext

This analysis looked at the effectiveness of a single vaccine dose (Pfizer or Oxford/AstraZeneca) against infection with SARS-CoV-2, using routine PCR test results for 10,412 residents (aged 65+ years) from 310 care homes across England. We observed vaccine effectiveness to be 56% between four and five weeks after vaccination, and 62% between five to seven weeks, with similar timing and level of protection for both vaccine types. Additionally, we found that people with prior infection were already well protected irrespective of vaccination status; and average Cycle Threshold (Ct) values of PCR-positive tests were higher from 28 days after vaccination compared to before vaccination (31.3 vs 26.6) - suggesting lower viral load, and therefore potentially reduced transmissibility, due to vaccination.

Krutikov, M., Palmer, T., Tut, G., Fuller, C., Shrotri, M., Williams, H., Davies, D., Irwin-Singer, A., Robson, J., Hayward, A., Moss, P., Copas, A. and Shallcross, L. (2021). Incidence of SARS-CoV-2 infection according to baseline antibody status in staff and residents of 100 long-term care facilities (VIVALDI study): a prospective cohort study. Lancet Healthy Longev 2021; 2: e362–70 doi.org/10.1016/S2666-7568(21)00093-3. Available at: https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(21)00093-3/fulltext 

In this study, VIVALDI researchers looked at rates of COVID-19 infections based on results from PCR testing between October 2020 and February 2021 among more than 2,000 care home residents and staff. They compared those who had evidence of a previous infection up to 10 months earlier, as determined by antibody testing, with those who had not been previously infected. They found that residents with a previous infection were 85% less likely to be infected during this four-month period than residents who had never been infected, while staff with past infection were 60% less likely than staff who had not had the infection before.

Krutikov, M., Hayward, A. and Shallcross, L. (2021) ‘Spread of a Variant SARS-CoV-2 in Long-Term Care Facilities in England’. N Engl J Med 2021; 384:1671-1673 doi.org/10.1056/NEJMc2035906
Available at: https://www.nejm.org/doi/full/10.1056/NEJMc2035906.

The study, published as a letter in the New England Journal of Medicine, described the initial spread of the alpha or Kent (B.1.1.7) SARS-CoV-2 variant in care homes between October and December 2020. Researchers looked at positive PCR tests processed at the Milton Keynes Lighthouse laboratory as part of Pillar 2 surveillance testing of care home staff and residents and found that, among the samples they had access to, the proportion of infections caused by the new variant rose from 12% in the week beginning 23 November to 60% of positive cases just two weeks later, in the week beginning 7 December. In the South East of England, where the variant was most dominant, the proportion increased from 55% to 80% over the same period. In London, where the variant spread fastest, the proportion increased from 20% to 66%. This suggests that the new variant spread as rapidly through care homes as in the general population.

Shallcross, L., Burke, D., Abbott, O., Donaldson, A., Hallatt, G., Hayward, A., Hopkins, S., Krutikov, M., Sharp, K., Wardman, L., Thorne, S. (2021). Factors associated with SARS-CoV-2 infection and outbreaks in long-term care facilities in England: a national cross-sectional survey. The Lancet Healthy Longevity, Volume 2, Issue 3. doi.org/10.1016/S2666-7568(20)30065-9
Available at: https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(20)30065-9/fulltext 

To identify the risk factors for SARS-CoV-2 infection and outbreaks in care homes, researchers conducted a cross-sectional survey of 5126 care homes in England that provide care to people older than 65 years between May 26 and June 19 2020. They found that half of care homes had not experienced any cases in the first pandemic wave. Lower transmission from staff was found in care homes who paid adequate sick pay, used low numbers of agency staff, had higher numbers of staff per resident, and implemented staff cohorting with either infected or uninfected residents. Risk factors for transmission of SARS-CoV-2 from residents were higher number of admissions of residents to the care homes and low compliance with isolation precautions.


Krutikov M, Palmer T, Donaldson A et al. (2020). Study Protocol: Understanding SARS-Cov-2 infection, immunity and its duration in care home residents and staff in England (VIVALDI). Wellcome Open Res 2021, 5:232 doi.org/10.12688/wellcomeopenres.16193.2
Available at: https://wellcomeopenresearch.org/articles/5-232/v2 

The study protocol for the VIVALDI study was published in Wellcome Open Research and outlines the study aims and methods. 

Impact of coronavirus in care homes in England: 26 May to 19 June 2020. (2020). Office for National Statistics. 
Available at: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/articles/impactofcoronavirusincarehomesinenglandvivaldi/26mayto19june2020 

This report was published following the first COVID-19 pandemic wave and outlines results of a cross-sectional survey conducted in collaboration with the Office for National Statistics (ONS) in 5126 care homes in England that provide care to people older than 65 years. Results showed that over half (56%) of care homes reported at least one confirmed case of SARS-CoV-2 (staff or resident) and in these care homes, one fifth (20%) of residents and under one-tenth (7%) of staff were infected.