Heterologous infection and vaccination shapes immunity against SARS-CoV-2 variants

[Figure: see text].The impact of initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infecting strain on downstream immunity to heterologous variants of concern (VOC) is unknown. Studying a longitudinal healthcare worker cohort, we found that after three antigen exposures (infection+two vaccine doses), S1 antibody, memory B cells and heterologous neutralization of B.1.351, P.1 and B.1.617.2 plateaued, while B.1.1.7 neutralization and spike T cell responses increased. Serology using Wuhan Hu-1 spike receptor binding domain poorly predicted neutralizing immunity against VOCs. Neutralization potency against VOCs changed with heterologous virus encounter and number of antigen exposures. Neutralization potency fell differentially depending on targeted VOCs over 5-months from the second vaccine dose. Heterologous combinations of spike encountered during infection and vaccination shape subsequent cross-protection against VOC, with implications for future-proof next-generation vaccines

Prior SARS-CoV-2 infection rescues B and T cell responses to variants after first vaccine dose

SARS-CoV-2 vaccine rollout has coincided with the spread of variants of concern. We investigated if single dose vaccination, with or without prior infection, confers cross protective immunity to variants. We analyzed T and B cell responses after first dose vaccination with the Pfizer/BioNTech mRNA vaccine BNT162b2 in healthcare workers (HCW) followed longitudinally, with or without prior Wuhan-Hu-1 SARS-CoV-2 infection. After one dose, individuals with prior infection showed enhanced T cell immunity, antibody secreting memory B cell response to spike and neutralizing antibodies effective against B.1.1.7 and B.1.351. By comparison, HCW receiving one vaccine dose without prior infection showed reduced immunity against variants. B.1.1.7 and B.1.351 spike mutations resulted in increased, abrogated or unchanged T cell responses depending on human leukocyte antigen (HLA) polymorphisms. Single dose vaccination with BNT162b2 in the context of prior infection with a heterologous variant substantially enhances neutralizing antibody responses against variants

Regime Type and Bilateral Treaty Formalization

How does domestic regime type affect bilateral cooperation, and one of its most visible manifestations, bilateral treaties? This article explains how domestic political regime affects bilateral cooperation and, contrary to the expectations of some scholars, why autocracies should be expected to be more likely than democracies to enter into bilateral treaties. If the preferences of a pair of states are not identical, the sets of agreements that each party would consent to (win-sets) need to overlap for a bilateral treaty to be acceptable. Because additional domestic constraints reduce the size of a country’s win-set, autocracies should have broader win-sets than democracies. Therefore, autocratic dyads should be more likely to formalize bilateral treaties than other pairs of states. Based on an original data set, I present empirical evidence showing that pairs of autocracies are more likely than other pairs of states to enter into agreements formalizing bilateral cooperation

Discordant neutralizing antibody and T cell responses in asymptomatic and mild SARS-CoV-2 infection

Understanding the nature of immunity following mild/asymptomatic infection with SARS-CoV-2 is crucial to controlling the pandemic. We analyzed T cell and neutralizing antibody responses in 136 healthcare workers (HCW) 16-18 weeks after United Kingdom lockdown, 76 of whom had mild/asymptomatic SARS-CoV-2 infection captured by serial sampling. Neutralizing antibodies (nAb) were present in 89% of previously infected HCW. T cell responses tended to be lower following asymptomatic infection than in those reporting case-definition symptoms of COVID-19, while nAb titers were maintained irrespective of symptoms. T cell and antibody responses were sometimes discordant. Eleven percent lacked nAb and had undetectable T cell responses to spike protein but had T cells reactive with other SARS-CoV-2 antigens. Our findings suggest that the majority of individuals with mild or asymptomatic SARS-CoV-2 infection carry nAb complemented by multispecific T cell responses at 16-18 weeks after mild or asymptomatic SARS-CoV-2 infection

COW Inter-State War Data, 1816-1997 (v3.0)

War takes many forms in the contemporary era, including serious military conflicts between states (inter-state war), between states and non-state actors (extra-state war), and within states (intra-state war). This data set records such events over the 1816-1997 period.Version 3.0 of the Correlates of War Inter-State War data set identifies interstate wars and their participants between 1816 and 1997. In any papers or publications that utilize this data set, users are asked to give the version number and cite the article of record for the data set, as follows: Bibliography Entry: Sarkees, Meredith Reid (2000). "The Correlates of War Data on War: An Update to 1997," Conflict Management and Peace Science, 18/1: 123-144

Diplomatic Exchange , 1817-2005 (v2006.1)

The Diplomatic Exchange data set tracks diplomatic representation at the level of chargé d'affaires, minister, and ambassador between states from 1817-2005. The Correlates of War Diplomatic Exchange data set captures diplomatic representation at the level of chargé d'affaires, minister, and ambassador between members of the Correlates of War interstate system. The 2006 version of the data set includes information for the following years: 1817, 1824, 1827, 1832, 1836, 1840, every five years between 1844 and 1914, every five years between 1920 and 1940, and every five years between 1950 and 2005. In any papers or publications that utilize this data set, users are asked to give the version number and cite the article of record for the data set, as follows: Bibliography Entry: Bayer, Reşat. 2006. “Diplomat ic Exchange Data set, v2006.1.” Online: http://correlatesofwar.or

Territorial Change, 1816-2000 (v3.0)

Territory has played an important role in interstate conflict, and this data set records all peaceful and violent changes of territory from 1816-2000. The territorial change dataset is the result of the effort to identify and code all territorial changes involving at least one nation-state (as defined by the Correlates of War project) for the period 1816-2000. The 1816-2000 version of this data set (v3.0) is an update of the earlier territorial change data set that ended in 1996. In this version, 10 new cases have been added for 1997-2000 time period. In addition, some minor changes/corrections have been made to existing data points. Full details of these modifications are included in the update documentation. In any papers or publications that utilize this data set, users are asked to give the version number and cite t he article of record for the data set, as follows: Bibliography Entry: Tir, Jaroslav, Philip Schafer, Paul Diehl, and Gary Goertz. 1998. "Territorial Changes, 1816-1996: Procedures and Data." Conflict Management and Peace Science 16(1):89-97

Replication data for: State System Membership List, v2004.1

This data set contains the list of states in the international system as updated and distributed by the Correlates of War Project. These data sets identify states, their standard Correlates of War "country code" or state number (used throughout the Correlates of War project data sets), state abbreviations, and dates of membership as states and major powers in the internationaly system. Version 2004.1 extends the temporal domain of the collection to 2004. Users note: The order of variables in this file has changed from the 2002 version. The variables were incorrectly ordered in the 2002 version of this data set, and did not match the documentation (the first two variables were switched). In the 2004 version, variables are now in the correct order, and are identical between the "states" and "majors" data sets