Search

Earlier global detection of novel SARS-CoV-2 variants gives governments more time to respond. However, few countries can implement timely national surveillance resulting in gaps in monitoring. The UK implemented large-scale community and hospital surveillance, but experience suggests it may be faster to detect new variants through testing UK arrivals for surveillance. We developed simulations of the emergence and importation of novel variants with a range of infection hospitalisation rates (IHR) to the UK. We compared time taken to detect the variant though testing arrivals at UK borders, hospital admissions, and the general community. We found that sampling 10-50% of arrivals at UK borders could confer a speed advantage of 3.5-6 weeks over existing community surveillance, and 1.5–5 weeks (depending on IHR) over hospital testing. We conclude that directing limited global capacity for surveillance to highly connected ports could speed up global detection of novel SARS-CoV-2 variants.

This paper examines whether monetary policy pass-through to mortgage interest rates affects household fertility decisions. Our empirical strategy exploits variation in households’ eligibility for a rate adjustment, coupled with the large reductions in the monetary policy rate that occurred during the Great Recession in the U.K. and U.S. We estimate that each one percentage point drop in the policy rate increased birth rates amongst households eligible for a rate adjustment by 3%. Our results provide new evidence on the nature of monetary policy transmission to households and suggest a new mechanism via which mortgage contract structures can affect both aggregate demand and supply.

The monkeypox epidemic in the UK began in May 2022, and subsequently and rather quickly, rates of new cases have declined during August 2022. Identifying the causes of this decline requires accurate estimates of the time-varying epidemic growth rate r(t), which in turn depend upon the reporting delays (defined as the time from onset of symptoms to presenting to healthcare). Using a custom nowcasting method which allows for time-varying delays (EpiLine), we show that the reporting delay for Monkeypox in the UK decreased from an average of 22 days in early May 2022 to 10 days by early June and 7 days in August 2022. Accounting for these dynamic delays shows that the time-varying r(t) declined gradually in the UK over this period. Not accounting for varying time delays would have incorrectly characterised r(t) by a sharp increase followed by a rapid drop. We discuss the importance of this gradual decline, which helps identify the potential mechanisms responsible for the decline in the rate of spread of Monkeypox, which was gradual and started well before vaccines were widely used.

Objective To analyse the transmission dynamics of the monkeypox outbreak in the UK, declared a Public Health Emergency of International Concern in July 2022. Design Contact tracing study, linking data on case-contact pairs and on probable exposure dates. Setting Case questionnaires from the UK Health Security Agency (UKHSA), United Kingdom. Participants 2746 people with polymerase chain reaction confirmed monkeypox virus in the UK between 6 May and 1 August 2022. Main outcome measures The incubation period and serial interval of a monkeypox infection using two bayesian time delay models—one corrected for interval censoring (ICC—interval censoring corrected) and one corrected for interval censoring, right truncation, and epidemic phase bias (ICRTC—interval censoring right truncation corrected). Growth rates of cases by reporting date, when monkeypox virus was confirmed and reported to UKHSA, were estimated using generalised additive models. Results The mean age of participants was 37.8 years and 95% reported being gay, bisexual, and other men who have sex with men (1160 out of 1213 reporting). The mean incubation period was estimated to be 7.6 days (95% credible interval 6.5 to 9.9) using the ICC model and 7.8 days (6.6 to 9.2) using the ICRTC model. The estimated mean serial interval was 8.0 days (95% credible interval 6.5 to 9.8) using the ICC model and 9.5 days (7.4 to 12.3) using the ICRTC model. Although the mean serial interval was longer than the incubation period for both models, short serial intervals were more common than short incubation periods, with the 25th centile and the median of the serial interval shorter than the incubation period. For the ICC and ICRTC models, the corresponding estimates ranged from 1.8 days (95% credible interval 1.5 to 1.8) to 1.6 days (1.4 to 1.6) shorter at the 25th centile and 1.6 days (1.5 to 1.7) to 0.8 days (0.3 to 1.2) shorter at the median. 10 out of 13 linked patients had documented pre-symptomatic transmission. Doubling times of cases declined from 9.07 days (95% confidence interval 12.63 to 7.08) on the 6 May, when the first case of monkeypox was reported in the UK, to a halving time of 29 days (95% confidence interval 38.02 to 23.44) on 1 August. Conclusions Analysis of the instantaneous growth rate of monkeypox incidence indicates that the epidemic peaked in the UK as of 9 July and then started to decline. Short serial intervals were more common than short incubation periods suggesting considerable pre-symptomatic transmission, which was validated through linked patient level records. For patients who could be linked through personally identifiable data, four days was the maximum time that transmission was detected before symptoms manifested. An isolation period of 16 to 23 days would be required to detect 95% of people with a potential infection. The 95th centile of the serial interval was between 23 and 41 days, suggesting long infectious periods.

Since May 2022, monkeypox virus (MPXV) has spread rapidly in high-income countries through close human-to-human contact primarily amongst communities of gay, bisexual and men who have sex with men (GBMSM). Behavioural change arising from increased knowledge and health warnings may have reduced the rate of transmission and Vaccinia-based vaccination is likely to be an effective longer-term intervention. We investigate the UK epidemic presenting 26-week projections using a stochastic discrete-population transmission model which includes GBMSM status, rate of formation of new sexual partnerships, and clique partitioning of the population. We find that MPXV cases peaked in mid-July, declining due to decreased transmission rate per infected individual and infection-induced immunity among GBMSM, especially those with the highest rate of new partners. We predict cases will remain low from October 2022 to March 2023 (20-65 cases a week), and a rebound in cases due to behaviour reversion prevented by high-risk group-targeted vaccination.

We investigate whether the dynamic response of aggregate consumption to monetary policy depends on the distribution of household debt relative to income. Using UK loan-level micro-data, we propose a novel approach to isolate the fraction of households with a limited ability to smooth consumption. By exploiting time and cross-sectional variation, we show that consumption responds more to monetary policy when the share of highly-indebted households is large, but find no state-contingency with respect to the overall level of debt-to-income. Our results highlight the role of household heterogeneity for understanding monetary transmission to aggregate consumption.

This paper examines whether monetary policy pass-through to mortgage interest rates affects household fertility decisions. Using administrative data on mortgages and births in the UK, our empirical strategy exploits variation in the timing of when families were eligible for a rate adjustment, coupled with the large reductions in the monetary policy rate that occurred during the Great Recession. We estimate that each 1 percentage point drop in the policy rate increased birth rates by 2 percent. In aggregate, this pass-through of accommodative monetary policy to mortgage rates was sufficiently large to outweigh the headwinds of the Great Recession and prevent a “baby bust” in the UK, in contrast to the US. Our results provide new evidence on the nature of monetary policy transmission to households and suggest a new mechanism via which mortgage contract structures can affect both aggregate demand and supply.

This paper investigates how the transmission of monetary policy to the real economy depends on the distribution of household debt. Using an original loan-level dataset covering the universe of UK mortgages, we assess the effect of monetary shocks on aggregate consumption by exploiting time variation in a measure of the proportion of households close to their borrowing constraint. We find that monetary policy is most potent when there is a large share of constrained households. In contrast, we find no evidence that the average level of borrowing relative-to-income of the household sector affects the transmission of monetary policy.

This paper quantifies the local impact of monetary policy through the cash-flow channel during the Crisis by combining novel micro datasets with near-universal coverage of UK mortgages and employment. I estimate that a reduction in mortgage payments equivalent to 1% of household income led to around a 5 percentage point increase in employment growth in non-tradable businesses the following year. But the spatial distribution of mortgage and labour market structures resulted in significant heterogeneity of this effect across the country. Taken at face value, the estimates suggest that the overall effect of accommodative monetary policy on total employment growth in 2010 varied by around 1.5 percentage points across regions.