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2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-334389

ABSTRACT

Third dose COVID-19 vaccines are being deployed widely but their efficacy has not been assessed adequately in vulnerable elderly people who exhibit suboptimal responses after primary series vaccination. We studied spike-specific immune responses in 341 staff and residents in long-term care facilities (LTCF) who received an mRNA vaccine following dual primary series vaccination with BNT162b2 or ChAdOx1. Third dose vaccination strongly increased antibody responses with preferential enhancement in older people and was required to elicit neutralisation of Omicron. Cellular immune responses were also enhanced with strong cross-reactive recognition of Omicron. However, antibody titres fell 21-78% within 100 days post vaccine and 27% of participants developed a breakthrough Omicron infection. These findings reveal strong immunogenicity of a 3rd vaccine in one of the most vulnerable population groups and endorse an approach for widespread delivery across this population. Ongoing assessment will be required to determine the stability of immune protection.

3.
J Infect Dis ; 2022 Apr 16.
Article in English | MEDLINE | ID: covidwho-1795251

ABSTRACT

General population studies have shown strong humoral response following SARS-CoV-2 vaccination with subsequent waning of anti-spike antibody levels. Vaccine-induced immune responses are often attenuated in frail and older populations, but published data are scarce. We measured SARS-CoV-2 anti-spike antibody levels in Long-Term Care Facility residents and staff following second vaccination dose with Oxford-AstraZeneca or Pfizer-BioNTech. Vaccination elicited robust antibody responses in older residents, suggesting comparable levels of vaccine-induced immunity to that in the general population. Antibody levels are higher after Pfizer-BioNTech vaccination but fall more rapidly compared to Oxford-AstraZeneca recipients and are enhanced by prior infection in both groups.

4.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330319

ABSTRACT

Background Long-term care facilities (LTCF) have been prioritised for vaccination, but data on potential waning of vaccine effectiveness (VE) and the impact of booster doses in this vulnerable population remains scarce. Methods We included residents and staff from 331 LTCFs enrolled in VIVALDI ( ISRCTN 14447421 ), who underwent routine PCR testing between Dec 8, 2020 - Dec 11, 2021 in a Cox proportional hazards regression, estimating VE against SARS-CoV2 infection, COVID-19-related hospitalisation, and COVID-19-related death after 1-3 vaccine doses, stratifying by previous SARS-CoV2 exposure. Results For 15,518 older residents, VE declined from 50·7% (15·5, 71·3) to 17·2% (∼23·9, 44·6) against infection;from 85·4% (60·7, 94·.6) to 54·3% (26·2, 71·7) against hospitalisation;and from 94·4% (76·4, 98·7) to 62·8% (32·9, 79·4) against death, when comparing 2-12 weeks and ≥12 weeks after two doses. For 19,515 staff, VE against infection declined slightly from 50·3% (32·7, 63·3) to 42·1% 29·5, 52·4). High VE was restored following a third dose, with VE of 71·6% (53·5, 82·7) and 78·3% (70·1, 84·3) against infection and 89·9% (80·0, 94·6) and 95·8% (50·4, 99·6) against hospitalisation, for residents and staff respectively;and 97·5% (88·1, 99·5) against death for residents. Interpretation Substantial waning of VE is observed against all outcomes in residents from 12 weeks after a primary course of AstraZeneca or mRNA vaccines. Boosters restore protection, and maximise immunity across all outcomes. These findings demonstrate the importance of boosting and the need for ongoing surveillance of VE in this vulnerable cohort. Funding UK Government Department of Health and Social Care. Research in Context Evidence before this study We searched MEDLINE and medRxiv for studies reporting vaccine effectiveness (VE) over time after two or three doses against SARS-CoV2 infection, COVID-19-related hospitalisation, or COVID-19-related death amongst staff or residents of long-term care facilities (LTCFs), that were published between Jan 1, 2020, and December 21, 2021. We used variations of the search terms “COVID-19” OR “SARS-CoV-2” AND “vaccine effectiveness” OR “vaccine efficacy” AND “care homes” OR “long term care facilities”. We identified 8 articles reporting two-dose data from LTCFs, including 1 peer-reviewed paper from Israel, 1 preprint from Denmark, 1 preprint from Norway, 1 peer-reviewed paper from France, two peer-reviewed papers from Spain, 1 peer-reviewed paper from the USA, and 1 preprint from England;however none of these studies examined waning of protection over time after two doses. Five studies (mRNA vaccines 3-4 weeks interval) reported short-term two-dose VE of 49-71% in residents, and 82-90% in staff. Two-dose VE was reported to be 75-88% against hospitalisation, 87-97% against death, and 86% against either outcome. An English study of residents (Pfizer or AstraZeneca, 8-12 week interval) reported 73% VE against infection and noted VE waning from 7 weeks after the first dose, but did not examine waning after the second dose. All of these studies were set prior to emergence of the Delta variant and did not examine waning of immunity due to short lengths of follow-up after Dose 2. Only one study (USA) compared Pfizer/Moderna two-dose VE against infection in LTCF residents before (67·5% [60·1-73·5%]) and during (53·1% [49·1-56·7%]) Delta variant predominance;however, authors could not access vaccination dates therefore did not account for any waning of immunity over time;they also did not examine any severe clinical outcomes. We identified only one correspondence piece from Israel (Pfizer 3-4 week interval) describing the benefit of a third ‘booster’ dose in LTCFs;it reported relative rate reductions of 71% for infection and 80%, for hospitalisation in the period after booster roll-out. However, individual-level VE estimates by time since vaccination were not reported, and adju tment for prior infection was not undertaken. Overall, there was a paucity of data on non-mRNA vaccines, waning of immunity over time after two doses, and VE following a third (booster) dose in LTCF populations, which we address in this study. Added value of this study We report findings from a prospective cohort study that includes 15,518 residents and 19,515 staff from 331 LTCFs across England, who underwent routine PCR testing 2-3 times per month, looking at SARS-CoV2 vaccine effectiveness over 12 months (Dec 8, 2020-Dec 11, 2021), which is the longest duration of follow-up of any study within this vulnerable cohort. We evaluated the effectiveness of first, second, and booster vaccine doses of AstraZeneca, Pfizer, and Moderna against infection, hospitalisation, and death over the 12 months when the Alpha and Delta variants were dominant. Our findings affirm that complete vaccination with two doses of AstraZeneca or mRNA vaccines offers moderate protection against infection, and high protection against severe clinical outcomes, however this protection declines over time, particularly for residents. A third booster dose of an mRNA vaccine restores, and indeed maximises, VE to 71·6% (53·5, 82·7) and 78·3% (70·1, 84·3) against infection, and 89·9% (80·0, 94·6) and 95·8% (50·4, 99·6) against hospitalisation, for residents and staff respectively, and to 97·5% (88·1, 99·5) against death for residents, with similar protection offered after the third dose irrespective of primary course type. This is the first study to examine and describe waning of immunity over a one-year period, as well as vaccine effectiveness of a booster dose, in a large cohort of LTCF staff and residents. Implications of all the available evidence Taken together, our findings indicate high short-term immunity against SARS-CoV2 infection and very high immunity against severe clinical outcomes of COVID-19 for LTCF residents and staff following vaccination. However substantial waning in vaccine-derived immunity is seen beyond 3 months, irrespective of vaccine type, suggesting the need for regular boosting to maintain protection in this vulnerable cohort. Although this analysis took place in the pre-Omicron period, these trends of waning immunity over time are likely to be generalisable across variants, carrying important implications for long-term vaccination policy in LTCFs. Ongoing surveillance in this vulnerable cohort remains crucial, in order to describe further changes in vaccine-induced immunity, particularly in the context of new variants.

5.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327186

ABSTRACT

Background General population studies have shown strong humoral response following SARS-CoV-2 vaccination with subsequent waning of anti-spike antibody levels. Vaccine-induced immune responses are often attenuated in frail and older populations such as Long-Term Care Facility (LTCF) residents but published data are scarce. Methods VIVALDI is a prospective cohort study in England which links serial blood sampling in LTCF staff and residents to routine healthcare records. We measured quantitative titres of SARS-CoV-2 anti-spike antibodies in residents and staff following second vaccination dose with ChAdOx1 nCov-19 (Oxford-AstraZeneca) or BNT162b2 (Pfizer-BioNTech). We investigated differences in peak antibody levels and rates of decline using linear mixed effects models. Results We report on 1317 samples from 402 residents (median age 86 years, IQR 78-91) and 632 staff (50 years, 37-58), ≤280 days from second vaccination dose. Peak antibody titres were 7.9-fold higher after Pfizer-BioNTech vaccine compared to Oxford-AstraZeneca (95%CI 3.6-17.0;P <0.01) but rate of decline was increased, and titres were similar at 6 months. Prior infection was associated with higher peak antibody levels in both Pfizer-BioNTech (2.8-fold, 1.9-4.1;P <0.01) and Oxford-AstraZeneca (4.8-fold, 3.2-7.1;P <0.01) recipients and slower rates of antibody decline. Increasing age was associated with a modest reduction in peak antibody levels for Oxford-AstraZeneca recipients. Conclusions Double-dose vaccination elicits robust and stable antibody responses in older LTCF residents, suggesting comparable levels of vaccine-induced immunity to that in the general population. Antibody levels are higher after Pfizer-BioNTech vaccination but fall more rapidly compared to Oxford-AstraZeneca recipients and are enhanced by prior infection in both groups.

6.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-323027

ABSTRACT

Background: Residents of long-term care facilities (LTCF) have experienced high mortality rates from SARS-CoV-2 infection and as such have been prioritized for Covid-19 vaccination. Several countries have implemented an extended interval of up to 12 weeks between first and second vaccine doses to increase population coverage after single administration. Methods: Spike-specific immune responses that were induced following single administration of BNT162b2 or ChAdOx1 were studied in 89 staff and 35 residents within LTCFs. Quantitative antibody and cellular responses were determined as well as antibody inhibition of spike protein-ACE2 binding from viral variants. Results: 20% of staff and 34% of residents were found to have serological evidence of prior SARS-CoV-2 infection and all of these donors demonstrated strong antibody responses that were independent of age. Antibody responses were detectable within 99% and 79% of ‘infection-naive’ staff and residents respectively but were 8.2-fold lower within residents. This effect resulted from slower kinetics of antibody generation within residents which reached levels comparable to staff after only 42 days. In contrast spike-specific cellular responses were equivalent between both groups. Antibody inhibition activity against the B.1.351 and P.1 viral variants of concern was low using serum from ‘infection-naive’ older donors. Prior history of natural infection thus has a marked impact on the magnitude and quality of antibody response after a single Covid-19 vaccine in care home residents. Interpretation: Residents who are infection-naive have delayed antibody responses to the first dose of vaccine and might be considered for an early second vaccine where possible. Funding: UK Government Department of Health and Social CareDeclaration of Interests: LS reports grants from the Department of Health and Social Care during the conduct of the study and is a member of the Social Care Working Group, which reports to the Scientific Advisory Group for Emergencies. AH is a member of the New and Emerging Respiratory Virus Threats Advisory Group at the Department of Health.Ethics Approval Statement: Ethical approval for this study was obtained from the South Central - Hampshire B Research Ethics Committee, REC Ref: 20/SC/023.

7.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-314568

ABSTRACT

Global infection and mortality rates from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are disproportionately high in certain populations, including amongst older people. Care home residents are frequently exposed to infection due to contact with staff and other residents, and are highly susceptible to infection due to their age and co-morbidity. In England, official statistics suggest that at least 25% of all deaths in care home residents since the start of pandemic are linked to coronavirus disease 2019 (COVID-19), but limited testing for SARS-CoV-2 early in the pandemic means estimates of the true burden of disease are lacking. Additionally, little is known about patterns of transmission between care homes, the community and hospitals, or the relationship between infection and immunity in care home staff and residents. The VIVALDI study plans to address these questions. VIVALDI is a prospective cohort study aiming to recruit  6,500 staff and 5000 residents from 105 care homes across England. Successive rounds of testing for infection will be performed over a period of 12 months.  Nasopharyngeal swabs will detect evidence of viral RNA and therefore active infection (accompanied by collection of data on symptoms), whereas blood tests will detect antibodies and evidence of cellular immunity to SARS-CoV-2. Whole genome sequencing of viral isolates to investigate pathways of transmission of infection is planned in collaboration with the COVID-19 Genomics UK Consortium. Qualitative interviews with care home staff will investigate the impact of the pandemic on ways of working and how test results influence infection control practices and behaviours. Data from residents and staff will be linked to national datasets on hospital admissions, antibody and PCR test results, mortality and care home characteristics.  Data generated will support national public health efforts to prevent transmission of COVID-19 and protect care home staff and residents from infection. Protocol registration : ISRCTN14447421 05/06/2020

8.
Lancet Healthy Longev ; 3(1): e13-e21, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1665611

ABSTRACT

Background: Long-term care facilities (LTCFs) have reported high SARS-CoV-2 infection rates and related mortality, but the proportion of infected people among those who have survived, and duration of the antibody response to natural infection, is unknown. We determined the prevalence and stability of nucleocapsid antibodies (the standard assay for detection of previous infection) in staff and residents in LTCFs in England. Methods: This was a prospective cohort study of residents 65 years or older and of staff 65 years or younger in 201 LTCFs in England between March 1, 2020, and May 7, 2021. Participants were linked to a unique pseudo-identifier based on their UK National Health Service identification number. Serial blood samples were tested for IgG antibodies against SARS-CoV-2 nucleocapsid protein using the Abbott ARCHITECT i-system (Abbott, Maidenhead, UK) immunoassay. Primary endpoints were prevalence and cumulative incidence of antibody positivity, which were weighted to the LTCF population. Incidence rate of loss of antibodies (seroreversion) was estimated from Kaplan-Meier curves. Findings: 9488 samples were included, 8636 (91·0%) of which could be individually linked to 1434 residents and 3288 staff members. The cumulative incidence of nucleocapsid seropositivity was 34·6% (29·6-40·0) in residents and 26·1% (23·0-29·5) in staff over 11 months. 239 (38·6%) residents and 503 women (81·3%) were included in the antibody-waning analysis, and median follow-up was 149 days (IQR 107-169). The incidence rate of seroreversion was 2·1 per 1000 person-days at risk, and median time to reversion was 242·5 days. Interpretation: At least a quarter of staff and a third of surviving residents were infected with SAR-CoV-2 during the first two waves of the pandemic in England. Nucleocapsid-specific antibodies often become undetectable within the first year following infection, which is likely to lead to marked underestimation of the true proportion of people with previous infection. Given that natural infection might act to boost vaccine responses, better assays to identify natural infection should be developed. Funding: UK Government Department of Health and Social Care.

9.
Lancet Infect Dis ; 21(11): 1529-1538, 2021 11.
Article in English | MEDLINE | ID: covidwho-1637724

ABSTRACT

BACKGROUND: The effectiveness of SARS-CoV-2 vaccines in older adults living in long-term care facilities is uncertain. We investigated the protective effect of the first dose of the Oxford-AstraZeneca non-replicating viral-vectored vaccine (ChAdOx1 nCoV-19; AZD1222) and the Pfizer-BioNTech mRNA-based vaccine (BNT162b2) in residents of long-term care facilities in terms of PCR-confirmed SARS-CoV-2 infection over time since vaccination. METHODS: The VIVALDI study is a prospective cohort study that commenced recruitment on June 11, 2020, to investigate SARS-CoV-2 transmission, infection outcomes, and immunity in residents and staff in long-term care facilities in England that provide residential or nursing care for adults aged 65 years and older. In this cohort study, we included long-term care facility residents undergoing routine asymptomatic SARS-CoV-2 testing between Dec 8, 2020 (the date the vaccine was first deployed in a long-term care facility), and March 15, 2021, using national testing data linked within the COVID-19 Datastore. Using Cox proportional hazards regression, we estimated the relative hazard of PCR-positive infection at 0-6 days, 7-13 days, 14-20 days, 21-27 days, 28-34 days, 35-48 days, and 49 days and beyond after vaccination, comparing unvaccinated and vaccinated person-time from the same cohort of residents, adjusting for age, sex, previous infection, local SARS-CoV-2 incidence, long-term care facility bed capacity, and clustering by long-term care facility. We also compared mean PCR cycle threshold (Ct) values for positive swabs obtained before and after vaccination. The study is registered with ISRCTN, number 14447421. FINDINGS: 10 412 care home residents aged 65 years and older from 310 LTCFs were included in this analysis. The median participant age was 86 years (IQR 80-91), 7247 (69·6%) of 10 412 residents were female, and 1155 residents (11·1%) had evidence of previous SARS-CoV-2 infection. 9160 (88·0%) residents received at least one vaccine dose, of whom 6138 (67·0%) received ChAdOx1 and 3022 (33·0%) received BNT162b2. Between Dec 8, 2020, and March 15, 2021, there were 36 352 PCR results in 670 628 person-days, and 1335 PCR-positive infections (713 in unvaccinated residents and 612 in vaccinated residents) were included. Adjusted hazard ratios (HRs) for PCR-positive infection relative to unvaccinated residents declined from 28 days after the first vaccine dose to 0·44 (95% CI 0·24-0·81) at 28-34 days and 0·38 (0·19-0·77) at 35-48 days. Similar effect sizes were seen for ChAdOx1 (adjusted HR 0·32, 95% CI 0·15-0·66) and BNT162b2 (0·35, 0·17-0·71) vaccines at 35-48 days. Mean PCR Ct values were higher for infections that occurred at least 28 days after vaccination than for those occurring before vaccination (31·3 [SD 8·7] in 107 PCR-positive tests vs 26·6 [6·6] in 552 PCR-positive tests; p<0·0001). INTERPRETATION: Single-dose vaccination with BNT162b2 and ChAdOx1 vaccines provides substantial protection against infection in older adults from 4-7 weeks after vaccination and might reduce SARS-CoV-2 transmission. However, the risk of infection is not eliminated, highlighting the ongoing need for non-pharmaceutical interventions to prevent transmission in long-term care facilities. FUNDING: UK Government Department of Health and Social Care.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunogenicity, Vaccine , Nursing Homes/statistics & numerical data , Age Factors , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/virology , COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Vaccines/administration & dosage , England/epidemiology , Female , Humans , Immunization Schedule , Incidence , Male , Mass Vaccination/methods , Mass Vaccination/statistics & numerical data , Prospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Treatment Outcome
10.
SSRN; 2021.
Preprint in English | SSRN | ID: ppcovidwho-297180

ABSTRACT

Background: Age and frailty are risk factors for poor clinical outcomes following SARS-CoV-2 infection. As such, COVID-19 vaccination has been prioritised for this group but there is concern that immune responses may be impaired due to immune senescence and co-morbidity. Methods: We studied antibody and cellular immune responses following COVID-19 vaccination in 202 staff and 286 residents of long-term care facilities (LTCF). Due to the high prevalence of previous infection within this environment 50% and 51% of these two groups respectively had serological evidence of prior natural SARS-CoV-2 infection. Results: In both staff and residents with previous infection the antibody responses following dual vaccination were strong and equivalent across the age course. In contrast, within infection-naïve donors these responses were reduced by 2.4-fold and 8.1-fold respectively such that values within the resident population were 2.6-fold lower than in staff. Impaired neutralisation of delta variant spike binding was also apparent within donors without prior infection. Spike-specific T cell responses were also markedly enhanced by prior infection and within infection-naive donors were 52% lower within residents compared to staff. Post-vaccine spike-specific CD4+ T cell responses displayed single or dual production of IFN-γ+ and IL-2+ whilst previous infection primed for an extended functional profile with TNF-ɑ+ and CXCL10 production. Interpretation: These data reveal suboptimal post-vaccine immune responses within infection-naïve elderly residents of LTCF and indicate the need for further optimization of immune protection through the use of booster vaccination.

11.
Euro Surveill ; 26(46)2021 11.
Article in English | MEDLINE | ID: covidwho-1526748

ABSTRACT

We describe the impact of changing epidemiology and vaccine introduction on characteristics of COVID-19 outbreaks in 330 long-term care facilities (LTCF) in England between November 2020 and June 2021. As vaccine coverage in LTCF increased and national incidence declined, the total number of outbreaks and outbreak severity decreased across the LTCF. The number of infected cases per outbreak decreased by 80.6%, while the proportion of outbreaks affecting staff only increased. Our study supports findings of vaccine effectiveness in LTCF.


Subject(s)
COVID-19 , Vaccines , Disease Outbreaks/prevention & control , Humans , Long-Term Care , SARS-CoV-2
12.
Lancet Healthy Longev ; 2(9): e544-e553, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1433991

ABSTRACT

BACKGROUND: Residents of long-term care facilities (LTCFs) have been prioritised for COVID-19 vaccination because of the high COVID-19 mortality in this population. Several countries have implemented an extended interval of up to 12 weeks between the first and second vaccine doses to increase population coverage of single-dose vaccination. We aimed to assess the magnitude and quality of adaptive immune responses following a single dose of COVID-19 vaccine in LTCF residents and staff. METHODS: From the LTCFs participating in the ongoing VIVALDI study (ISRCTN14447421), staff and residents who had received a first dose of COVID-19 vaccine (BNT162b2 [tozinameran] or ChAdOx1 nCoV-19), had pre-vaccination and post-vaccination blood samples (collected between Dec 11, 2020, and Feb 16, 2021), and could be linked to a pseudoidentifier in the COVID-19 Data Store were included in our cohort. Past infection with SARS-CoV-2 was defined on the basis of nucleocapsid-specific IgG antibodies being detected through a semiquantitative immunoassay, and participants who tested positive on this assay after but not before vaccination were excluded from the study. Processed blood samples were assessed for spike-specific immune responses, including spike-specific IgG antibody titres, T-cell responses to spike protein peptide mixes, and inhibition of ACE2 binding by spike protein from four variants of SARS-CoV-2 (the original strain as well as the B.1.1.7, B.1.351, and P.1 variants). Responses before and after vaccination were compared on the basis of age, previous infection status, role (staff or resident), and time since vaccination. FINDINGS: Our cohort comprised 124 participants from 14 LTCFs: 89 (72%) staff (median age 48 years [IQR 35·5-56]) and 35 (28%) residents (87 years [77-90]). Blood samples were collected a median 40 days (IQR 25-47; range 6-52) after vaccination. 30 (24%) participants (18 [20%] staff and 12 [34%] residents) had serological evidence of previous SARS-CoV-2 infection. All participants with previous infection had high antibody titres following vaccination that were independent of age (r s=0·076, p=0·70). In participants without evidence of previous infection, titres were negatively correlated with age (r s=-0·434, p<0·0001) and were 8·2-times lower in residents than in staff. This effect appeared to result from a kinetic delay antibody generation in older infection-naive participants, with the negative age correlation disappearing only in samples taken more than 42 days post-vaccination (r s=-0·207, p=0·20; n=40), in contrast to samples taken after 0-21 days (r s=-0·774, p=0·0043; n=12) or 22-42 days (r s=-0·437, p=0·0034; n=43). Spike-specific cellular responses were similar between older and younger participants. In infection-naive participants, antibody inhibition of ACE2 binding by spike protein from the original SARS-CoV-2 strain was negatively correlated with age (r s=-0·439, p<0·0001), and was significantly lower against spike protein from the B.1.351 variant (median inhibition 31% [14-100], p=0·010) and the P.1 variant (23% [14-97], p<0·0001) than against the original strain (58% [27-100]). By contrast, a single dose of vaccine resulted in around 100% inhibition of the spike-ACE2 interaction against all variants in people with a history of infection. INTERPRETATION: History of SARS-CoV-2 infection impacts the magnitude and quality of antibody response after a single dose of COVID-19 vaccine in LTCF residents. Residents who are infection-naive have delayed antibody responses to the first dose of vaccine and should be considered for an early second dose where possible. FUNDING: UK Government Department of Health and Social Care.

13.
Lancet Healthy Longev ; 2(3): e129-e142, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1284651

ABSTRACT

BACKGROUND: Outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have occurred in long-term care facilities (LTCFs) worldwide, but the reasons why some facilities are particularly vulnerable to outbreaks are poorly understood. We aimed to identify factors associated with SARS-CoV-2 infection and outbreaks among staff and residents in LTCFs. METHODS: We did a national cross-sectional survey of all LTCFs providing dementia care or care to adults aged 65 years or older in England between May 26 and June 19, 2020. The survey collected data from managers of eligible LTCFs on LTCF characteristics, staffing factors, the use of disease control measures, and the number of confirmed cases of infection among staff and residents in each LTCF. Survey responses were linked to individual-level SARS-CoV-2 RT-PCR test results obtained through the national testing programme in England between April 30 and June 13, 2020. The primary outcome was the weighted period prevalence of confirmed SARS-CoV-2 infections in residents and staff reported via the survey. Multivariable logistic regression models were fitted to identify factors associated with infection in staff and residents, an outbreak (defined as at least one case of SARS-CoV-2 infection in a resident or staff member), and a large outbreak (defined as LTCFs with more than a third of the total number of residents and staff combined testing positive, or with >20 residents and staff combined testing positive) using data from the survey and from the linked survey-test dataset. FINDINGS: 9081 eligible wLTCFs were identified, of which 5126 (56·4%) participated in the survey, providing data on 160 033 residents and 248 594 staff members. The weighted period prevalence of infection was 10·5% (95% CI 9·9-11·1) in residents and 3·8% (3·4-4·2) in staff members. 2724 (53·1%) LTCFs reported outbreaks, and 469 (9·1%) LTCFs reported large outbreaks. The odds of SARS-CoV-2 infection in residents (adjusted odds ratio [aOR] 0·80 [95% CI 0·75-0·86], p<0·0001) and staff (0·70 [0·65-0·77], p<0·0001), and of large outbreaks (0·59 [0·38-0·93], p=0·024) were significantly lower in LTCFs that paid staff statutory sick pay compared with those that did not. Each one unit increase in the staff-to-bed ratio was associated with a reduced odds of infection in residents (0·82 [0·78-0·87], p<0·0001) and staff (0·63 [0·59-0·68], p<0·0001. The odds of infection in residents (1·30 [1·23-1·37], p<0·0001) and staff (1·20 [1·13-1·29], p<0·0001), and of outbreaks (2·56 [1·94-3·49], p<0·0001) were significantly higher in LTCFs in which staff often or always cared for both infected or uninfected residents compared with those that cohorted staff with either infected or uninfected residents. Significantly increased odds of infection in residents (1·01 [1·01-1·01], p<0·0001) and staff (1·00 [1·00-1·01], p=0·0005), and of outbreaks (1·08 [1·05-1·10], p<0·0001) were associated with each one unit increase in the number of new admissions to the LTCF relative to baseline (March 1, 2020). The odds of infection in residents (1·19 [1·12-1·26], p<0·0001) and staff (1·19 [1·10-1·29], p<0·0001), and of large outbreaks (1·65 [1·07-2·54], p=0·024) were significantly higher in LTCFs that were for profit versus those that were not for profit. Frequent employment of agency nurses or carers was associated with a significantly increased odds of infection in residents (aOR 1·65 [1·56-1·74], p<0·0001) and staff (1·85 [1·72-1·98], p<0·0001), and of outbreaks (2·33 [1·72-3·16], p<0·0001) and large outbreaks (2·42 [1·67-3·51], p<0·0001) compared with no employment of agency nurses or carers. Compared with LTCFs that did not report difficulties in isolating residents, those that did had significantly higher odds of infection in residents (1·33 [1·28-1·38], p<0·0001) and staff (1·48 [1·41-1·56], p<0·0001), and of outbreaks (1·84 [1·48-2·30], p<0·0001) and large outbreaks (1·62 [1·24-2·11], p=0·0004). INTERPRETATION: Half of LTCFs had no cases of SARS-CoV-2 infection in the first wave of the pandemic. Reduced transmission from staff is associated with adequate sick pay, minimal use of agency staff, an increased staff-to-bed ratio, and staff cohorting with either infected or uninfected residents. Increased transmission from residents is associated with an increased number of new admissions to the facility and poor compliance with isolation procedures. FUNDING: UK Government Department of Health and Social Care.

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