Is a COVID-19 Vaccine Likely to Make Things Worse?

A framework for long-lasting, slowly varying transient dynamics

Much of the focus of applied dynamical systems is on asymptotic dynamics such as equilibria and periodic solutions. However, in many systems there are transient phenomena, such as temporary population collapses and the honeymoon period after the start of mass vaccination, that can last for a very long time and play an important role in ecological and epidemiological applications. In previous work we defined transient centers which are points in state space that give rise to arbitrarily long and arbitrarily slow transient dynamics. Here we present the mathematical properties of transient centers and provide further insight into these special points. We show that under certain conditions, the entire forward and backward trajectory of a transient center, as well as all its limit points must also be transient centers. We also derive conditions that can be used to verify which points are transient centers and whether those are reachable transient centers. Finally we present examples to demonstrate the utility of the theory, including applications to predatory-prey systems and disease transmission models, and show that the long transience noted in these models are generated by transient centers.

An empirical analysis of American Passenger's willingness to fly in commercial airplanes after vaccination against COVID-19

Although several studies have explored the effects of the pandemic on aviation, little remains known about whether members of the public are willing to fly again after they have been vaccinated. The current study uses the Health Belief Model (HBM) to fill this missing gap by manipulating the following variables: 1) whether or not the participant is vaccinated; 2) whether or not airlines require that all passengers and crew receive vaccinations; 3) length of flight; 4) destination; and 5) the number of passengers. The data from 678 participants revealed that willingness to fly is much higher if the participants themselves have been vaccinated, if the airlines require all passengers to be vaccinated, if the flight is short, if the destination is domestic, and if the number of passengers is low. These findings did not appear to differ as a function of flying business versus pleasure. We discuss the practical implications of these data as airlines struggle to bring back their customer base.

Vaccination or NPI? A conjoint analysis of German citizens' preferences in the context of the COVID-19 pandemic

This research uses discrete choice-based conjoint analysis that elicits the preference structure of German citizens when it comes to their timely intention to vaccinate. The focus is on the trade-offs between pharmaceuticals (vaccine) and "non-pharmaceutical interventions" (NPIs) such as lock-downs and social distancing measures, as well as the value of voluntary versus mandatory compliance to the citizens. Our results highlight three critical insights: (a) value of waiting: at 70% effective vaccine, 1/3 of citizens still would prefer to be vaccinated in the next 6 months rather than immediately; (b) costs of NPI constraints: an effective vaccine may come as a solution to compensate for the costs induced by invasive NPI imposed for an extended period; (c) freedom of choice: voluntary compliance is preferred by citizens over imposed measures whether it relates to vaccination choice, lock-down measures, or work location choice during the pandemic. Backing up those findings in monetary value, a quick shot of a 100% effective vaccination is estimated to be worth in the range of 11,400€. Still, the value of the shot quickly falls to no value when effectiveness drops below 50. At the same time, the cost of imposing protective rules lies in the range of 1500-2500€, depending on the rule analyzed. In comparison, the burden of extra complete lock-down and social distancing is about 775€ per citizen per month. As most current vaccines are being proven to have high efficacy, a strategy that selects the most effective vaccine candidates while emphasizing how the vaccine may stop the pain of lasting lock-downs will be appropriate to nudge the population towards vaccination. Control measures that are too restrictive may be welfare-deteriorating, but enough NPI measures must be recommended as long as vaccination adoption is not sufficiently large.

In or Out? Identifying the Factors Playing a Role in Covid-19 Decision Making in Turkiye

OBJECTIVE

The study aimed at investigating the social, demographic, and economic factors affecting Covid-19 vaccine decisions before the vaccination started in Turkey. The study also aimed to understand the attitudes towards Covid-19 vaccines.

METHODS

The study was conducted by exploiting the data of 693 individuals living in Turkey. The data was collected via a virtually applied questionnaire according to snowball sampling in late 2020 when the vaccination program had not started in Turkey yet. Multinomial logistic regression design was used to identify the factors affecting Covid-19 vaccine decisions.

RESULTS

It was observed that Covid-19 vaccine acceptance was notably low before the vaccination started in Turkey. Further, almost 50% of the participants were indecisive about getting vaccinated. It was identified that age, gender, educational status, and residential status, as well as occupational status, the number of dependents, smoking, and the vaccination of governmental authorities, have associations with Covid-19 vaccination decisions.

CONCLUSIONS

Covid-19 vaccine acceptance is generally low, although it is relatively high among vulnerable groups (i.e., the elderly and smokers), and among those who are unable to isolate themselves. In addition, the vaccination of governmental authorities is remarkably effective on Covid-19 vaccine acceptance in Turkey.

Changes in preventive behaviour after COVID-19 vaccination in Thailand: a cross-sectional study

Background

Protective behaviours (e.g., mask-wearing, handwashing, avoiding social gatherings) and mass vaccination are effective ways to control the coronavirus disease 2019 (COVID-19) pandemic. Previous studies found that people who get vaccinated may change their protective behaviours. The Thai government has endorsed several mix-and-match vaccine regimens to eliminate the insufficiency of each vaccine brand. This study aimed to determine levels of protective behavioural changes after COVID-19 vaccination and its relationship with various vaccine regimens in Thailand.

Methods

A descriptive cross-sectional study was conducted between September 13, 2021, and January 14, 2022. Data were collected using an online questionnaire distributed via social media platforms and posters in public places in Thailand. The questionnaire comprised six items for demographic characteristics, seven items for COVID-19 vaccine regimens, and four items for protective behaviours. The vaccinated Thai population aged ≥ 18 years were surveyed. Statistical analyses included a Chi-squared test, Wilcoxon signed rank test, and multivariate logistic regressions.

Results

Of the 469 participants, more than half were females (67.4%), single (57.4%), and lived in an urban area (67.2%). Significant differences were observed with regard to median scores in handwashing (5.0 vs. 5.0, p-value < 0.001), physical distancing (4.0 vs. 5.0, p-value = 0.019), and avoiding social activity (4.0 vs. 5.0, p-value = 0.010) in pre- and post-vaccination situations. Approximately 70–90% of the participants did not report changes in protective behaviours after vaccination. Overall, 17.4%, 13.9%, and 12.7% of participants showed improvements in avoiding social activity, physical distancing, and handwashing respectively. Multivariate analysis revealed that improvements in protective behaviours were significantly associated with the age group (between 18 and 24 years), non-healthcare worker status, and those who lived in urban areas. No significant evidence of vaccine regimens was found relative to improved protective behaviours.

Conclusion

This evidence revealed that Thai people maintain their protective behaviours after vaccination but rather improved them. Moreover, demographic data were significantly associated with improved protective behaviours, but various vaccine regimens were not. These findings might be useful for implementing policies to maintain personal protective behaviours after vaccination against COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14494-x.

Non-pharmaceutical interventions during the roll out of covid-19 vaccines

Yi Zhang and colleagues call for continued use of non-pharmaceutical interventions to control covid-19 during and after vaccine roll outs

Identify and measure the degree of over-prevention behaviors in the post-COVID-19 era in China

Background

With the spread of vaccines, more and more countries have controlled the outbreak of the COVID-19. In this post-epidemic era, these countries began to revive their economy. However, pollution remains in the environment, and people’s physical and psychological health has been under threat due to some over-prevention behaviors. Instruments for governmental agencies to manage these behaviors are not yet available. This study aims to develop a measurement model to identify and measure the degree of over-prevention behaviors during the COVID-19 epidemic in China.

Methods

A survey online was conducted to collect cognition from 1528 Chinese people, including descriptions of various over-prevention behaviors defined by health authorities. Factor analyses were used to develop the measurement model and test its validity. Logistic regression analyses were conducted to explore demographic characteristics, indicating people who are inclined to exhibit over-prevention behaviors.

Results

Four main factors were extracted to develop the model (eigenvalue = 7.337, 3.157, 1.447, and 1.059, respectively). The overall reliability (Cronbach’s α = 0.900), the convergent (AVE > 0.5, CR > 0.8 for each factor) and discriminant validity is good. There is also a good internal consistency among these factors (Cronbach’s α = 0.906, 0.852, 0.882, and 0.763, respectively). In Factor 1, gender has a negative effect (Beta = − 0.294, P <  0.05, OR = 0.745), whereas employment has a positive effect. Workers in institutions exhibit the greatest effect (Beta = 0.855, P <  0.001, OR = 2.352). In Factor 2, employment has a negative effect, with workers in institutions exhibit the greatest role (Beta = − 0.963, P <  0.001, OR = 0.382). By contrast, education level has a positive effect (Beta = 0.430, P <  0.001, OR = 1.537). In Factor 3, age plays a negative role (Beta = − 0.128, P < 0.05, OR = 0.880).

Conclusions

People show a discrepancy in the cognition toward various over-prevention behaviors. The findings may have implications for decision-makers to reduce the contradiction between the epidemic and economic revival via managing these behaviors.

COVID-19 vaccine effectiveness among the staff of the Bologna Health Trust, Italy, December 2020-April 2021

Background and aim:

Randomized controlled trials have shown that mRNA vaccines are highly effective in preventing SARS-CoV2 infection. We conducted a study to assess the real-world effectiveness of mRNA vaccines (Pfizer-BioNTech or Moderna) in preventing all and symptomatic SARS-CoV2 infections and COVID-19 related hospitalizations in the staff of the Bologna Health Trust (HT), Italy

Methods:

We followed up retrospectively 9839 staff of the Bologna HT from December 27, 2020 to April 3, 2020 and calculated the effectiveness in partially and fully vaccinated subjects by applying a multivariable Cox proportional hazard model.

Results:

Vaccine effectiveness in preventing SARS-CoV2 infections is 85.5% (95%CI: 75.9-91.3) in the partially vaccinated and 84.8% (95%CI: 73.2-91.4) in the fully vaccinated. In preventing symptomatic infection effectiveness is 81.7% (95%CI: 62.7-91.0) in the partially and 87.1% (95%CI: 69.3-94.6) in the fully vaccinated. There were no COVID-19-related hospitalizations in the partially or fully vaccinated vs 15 hospitalization in the unvaccinated cohort.

Conclusions:

Our results confirm the effectiveness of mRNA vaccines in a real-world setting in Northern Italy.

High Rates of COVID-19 Vaccine Hesitancy and Its Association with Conspiracy Beliefs: A Study in Jordan and Kuwait among Other Arab Countries

Vaccination could be an effective strategy for slowing the spread of the current coronavirus disease 2019 (COVID-19) pandemic. Vaccine hesitancy could pose a serious problem for COVID-19 prevention, due to the spread of misinformation surrounding the ongoing pandemic. The aim of this study was to assess the attitudes towards the prospective COVID-19 vaccines among the general public in Jordan, Kuwait and other Arab countries. We also aimed to assess the association between COVID-19 vaccine acceptance and conspiracy beliefs. This study used an online survey distributed in December 2020, with items assessing conspiracies regarding COVID-19's origin and vaccination. Attitudes towards COVID-19 vaccines were assessed using the Vaccine Conspiracy Belief Scale (VCBS), with higher scores indicating a greater belief in vaccine conspiracy. A total of 3414 respondents completed the survey, the majority being residents of Jordan (n = 2173, 63.6%), Kuwait (n = 771, 22.6%) and Saudi Arabia (n = 154, 4.5%). The acceptance rates for COVID-19 and influenza vaccines were 29.4% and 30.9%, respectively. Males, respondents with higher educational levels and those with histories of chronic disease had higher rates of COVID-19 vaccine acceptance. Beliefs that COVID-19 vaccines are intended to inject microchips into recipients and that the vaccines are related to infertility were found in 27.7% and 23.4% of respondents, respectively. Higher VCBS scores were found among females, respondents with lower educational levels and respondents relying on social media platforms as the main source of information. The high rates of vaccine hesitancy in Jordan and Kuwait, among other Arab countries, are alarming. They could hinder the proper control of COVID-19 in the region. The harmful effect of COVID-19 misinformation and conspiracy beliefs was manifested in vaccine hesitancy. This may represent a massive obstacle to the successful control of the pandemic. A reliance on social media as the main source of information about COVID-19 vaccines was associated with vaccine hesitancy. This should alert governments, policy makers and the general public to the importance of vigilant fact checking.