The redistributive effects of pandemics: Evidence on the Spanish flu

Structural mapping of polyclonal IgG responses to HA after influenza virus vaccination or infection

Cellular and molecular characterization of immune responses elicited by influenza virus infection and seasonal vaccination have informed efforts to improve vaccine efficacy, breadth, and longevity. Here, we use negative stain electron microscopy polyclonal epitope mapping (nsEMPEM) to structurally characterize the humoral IgG antibody responses to hemagglutinin (HA) from human patients vaccinated with a seasonal quadrivalent flu vaccine or infected with influenza A viruses. Our data show that both vaccinated and infected patients had humoral IgGs targeting highly conserved regions on both H1 and H3 subtype HAs, including the stem and anchor, which are targets for universal influenza vaccine design. Responses against H1 predominantly targeted the central stem epitope in infected patients and vaccinated donors, whereas head epitopes were more prominently targeted on H3. Responses against H3 were less abundant, but a greater diversity of H3 epitopes were targeted relative to H1. While our analysis is limited by sample size, on average, vaccinated donors responded to a greater diversity of epitopes on both H1 and H3 than infected patients. These data establish a baseline for assessing polyclonal antibody responses in vaccination and infection, providing a context for future vaccine trials and emphasizing the need for further characterization of protective responses toward conserved epitopes. (201 words)IMPORTANCESeasonal influenza viruses cause hundreds of thousands of deaths each year and up to a billion infections; under the proper circumstances, influenza A viruses with pandemic potential could threaten the lives of millions more. The variable efficacies of traditional influenza virus vaccines and the desire to prevent pandemic influenzas have motivated work toward finding a universal flu vaccine. Many promising universal flu vaccine candidates currently focus on guiding immune responses to highly conserved epitopes on the central stem of the influenza hemagglutinin viral fusion protein. To support the further development of these stem-targeting vaccine candidates, in this study, we use negative stain electron microscopy to assess the prevalence of central stem-targeting antibodies in individuals who were exposed to influenza antigens through traditional vaccination and/or natural infection during the 2018-2019 flu season.

Revisiting Pearl's influenza studies by bootstrapping for forward variable selection with a null factor

In 1919 and 1921 Raymond Pearl published four empirical studies on the Spanish Flu epidemic in which he explored the factors that might explain the explosiveness and destructiveness of the epidemic in America's largest cities. Using partial correlation coefficients he tried to isolate the net effects of the possible explanatory factors, such as general demographic characteristics of the cities and death rates for various diseases, on the variables measuring the severity of the epidemic. Instead of Pearl's correlation analysis, we apply a bootstrap simulation to forward variable selection with a null factor for generalized linear regression with AICc validation. The null factor or pseudo-variable is a random variable that is independent of the response. The number of times it is included in the model selection simulation provides an important metric for deciding which terms should remain in the model. Our results are largely consistent with Pearl's conclusions in that the pre-pandemic death rates from organic heart disease and from all causes are most predictive of pandemic explosiveness or severity. However, our results also contain substantive nuances. Our paper contributes to the literature showing that state-of-the-art methodology for variable selection proves useful for historical epidemiology.

Structural Mapping of Polyclonal IgG Responses to HA After Influenza Virus Vaccination or Infection

Cellular and molecular characterization of immune responses elicited by influenza virus infection and seasonal vaccination have informed efforts to improve vaccine efficacy, breadth, and longevity. Here, we use negative stain electron microscopy polyclonal epitope mapping (nsEMPEM) to structurally characterize the humoral IgG antibody responses to hemagglutinin (HA) from human patients vaccinated with a seasonal quadrivalent flu vaccine or infected with influenza A viruses. Our data show that both vaccinated and infected patients had humoral IgGs targeting highly conserved regions on both H1 and H3 subtype HAs, including the stem and anchor, which are targets for universal influenza vaccine design. Responses against H1 predominantly targeted the central stem epitope in infected patients and vaccinated donors, whereas head epitopes were more prominently targeted on H3. Responses against H3 were less abundant, but a greater diversity of H3 epitopes were targeted relative to H1. While our analysis is limited by sample size, on average, vaccinated donors responded to a greater diversity of epitopes on both H1 and H3 than infected patients. These data establish a baseline for assessing polyclonal antibody responses in vaccination and infection, providing context for future vaccine trials and emphasizing the importance of carefully designing vaccines to boost protective responses towards conserved epitopes.

What can we learn from historical pandemics? A systematic review of the literature

What are the insights from historical pandemics for policymaking today? We carry out a systematic review of the literature on the impact of pandemics that occurred since the Industrial Revolution and prior to Covid-19. Our literature searches were conducted between June 2020 and September 2023, with the final review encompassing 169 research papers selected for their relevance to understanding either the demographic or economic impact of pandemics. We include literature from across disciplines to maximise our knowledge base, finding many relevant articles in journals which would not normally be on the radar of social scientists. Our review identifies two gaps in the literature: (1) the need to study pandemics and their effects more collectively rather than looking at them in isolation; and (2) the need for more study of pandemics besides 1918 Spanish Influenza, especially milder pandemic episodes. These gaps are a consequence of academics working in silos, failing to draw on the skills and knowledge offered by other disciplines. Synthesising existing knowledge on pandemics in one place provides a basis upon which to identify the lessons in preparing for future catastrophic disease events.

Socioeconomic mortality differences during the Great Influenza in Spain

Despite being one of the deadliest viruses in history, there is limited information on the socioeconomic factors that affected mortality rates during the Great Influenza Pandemic. In this study, we use occupation-province level data to investigate the relationship between influenza excess mortality rates and occupation-related status in Spain. We obtain three main results. Firstly, individuals in low-income occupations experienced the highest excess mortality, pointing to a notable income gradient. Secondly, professions that involved more social interaction were associated with a higher excess of mortality, regardless of income. Finally, we observe a substantial rural mortality penalty, even after controlling for income-related occupational groups. Based on this evidence, it seems that the high number of deaths was caused by not self-isolating. Some individuals did not quarantine themselves because they could not afford to miss work. In rural areas, home confinement was likely more limited because their inhabitants did not have immediate access to information about the pandemic or fully understand its impact due to their limited experience handling influenza outbreaks.

Global pandemic vaccine development, production and distribution challenges for the world population

BACKGROUND

The new type of virus (SARS-CoV-2 or COVID-19) from Coronaviridae family, discovered in 2019, caused a global pandemic with several massive lock-downs around the globe. Science and politicians became the center of world attention, receiving many questions without having clear answers. The hopes of many rested on vaccine development, which was done fast, facing novel challenges such as the massive production and distribution for several billions of people.

OBJECTIVE

In this paper, the global reaction to the pandemic is reviewed along with some critical comments.

METHOD

Different groups, including nations, took part in global lockdowns, while vaccine development was running in parallel without having enough capacity for some of the biggest medical demands in history. This review will bring together views from all interested groups in this pandemic crisis.

RESULTS

The Western world waited too long (4 months), after the first case was confirmed in China, to introduce lock-down and safety measures. On the other side, vaccine development was done too fast to give clear long-term safety profiles of the medications developed. Due to the focus on development, it was overlooked that production and distribution of sterile products such as vaccines might have limitations globally. Usually when such limitations occur, power comes to the surface. Therefore, buyers who had power will get the vaccines they need first. However, we should recognize the economic impact that directly influenced healthcare funding. All of this will lead to post-crisis challenges, including depression, violence, suicide, migration, and many other social problems.

CONCLUSIONS

The COVID-19 pandemic is a test for all of us, which many governments, industries and non-state actors are failing. It is a perfect "general probe" to detect some of the weaknesses of the current structure of global health. If politics and science do not work together to make a global production plan for vaccines and learn from this pandemic, then all of the lives lost were for nothing.

A Literature Review of Pandemics and Development: the Long-Term Perspective

Pandemics have been a long-standing object of study by economists, albeit with declining interest, that is until COVID-19 arrived. We review current knowledge on the pandemics' effects on long-term economic development, spanning economic and historical debates. We show that all economic inputs are potentially affected. Pandemics reduce the workforce and human capital, have mixed effects on investment and savings, but potentially positive consequences for innovation and knowledge development, depending on accompanying institutional change. In the absence of an innovative response supporting income redistribution, pandemics tend to increase income inequalities, worsening poverty traps and highlighting the distributional issues built into insurance-based health insurance systems. We find that the effects of pandemics are asymmetric over time, in space, and among sectors and households. Therefore, we suggest that the research focus on the theoretical plausibility and empirical significance of specific mechanisms should be complemented by meta-analytic efforts aimed at reconstructing the resulting complexity. Finally, we suggest that policymakers prioritize the development of organizational learning and innovative capabilities, focusing on the ability to adapt to emergencies rather than developing rigid protocols or mimicking solutions developed and implemented in different contexts.

Do Disease Epidemics Stimulate or Repress Entrepreneurial Activity?

This study addresses a unique angle by examining an under looked determinant of entrepreneurship related to disease epidemics. In times of natural disasters, such as disease epidemics, new demands emerge that might promote entrepreneurship. Using data on a large cross section of countries, we empirically test whether and to what extent the incidence and severity of disease epidemics affect the prevalence of entrepreneurship. The results show that both the occurrence and severity of epidemics spur entrepreneurial activity. These results highlight a potentially important role served by entrepreneurs in responding to biological disasters. Our findings withstand a series of robustness checks.