The development of vaccination by Edward Jenner in 1796 is seen by many as one of the most important and world-changing medical discoveries ever made. Throughout human history, smallpox was responsible for an untold and innumerable share of fatalities, with epidemics devastating countries (and even continents) in their wake; as of 1980, the World Health Organization declared smallpox to be eliminated in nature, making it the only human disease to have been successfully eradicated. If we look at the share of smallpox deaths in England over the nineteenth century, we can see the impact that vaccination had on society during this time. Decline in Britain Within this century, the number of people dying annually from smallpox dropped from 3,000 per million people in the 1700s, to just ten people per million in the 1890s (it is also worth noting that a smallpox pandemic swept across Britain between 1891 and 1893, which caused this number to be higher than it could have been). Mandatory vaccination was not introduced in England until 1853, but by this point the number of smallpox deaths per million people had already fallen to a fraction of its eighteenth century level, and compulsory vaccination reduced these numbers even further.

In the history of the United States, smallpox played a pivotal role in shaping the direction of the country's development. When Europeans first arrived in the Americas, they unintentionally introduced smallpox to the continent and the disease helped to wipe out as much as 95 percent of indigenous Americans. This was one factor that allowed European settlers to colonize the continent with relative ease, although the disease remained active in the Americas until the second half of the twentieth century. The number of smallpox cases in the United States fluctuated between 1900 and 1930, with as many as 110,000 reported cases in 1920, however the number of cases fell sharply in the 1930s, and there were no cases at all in the United States from 1950 onwards. In 1980, the World Health Organization declared the disease to be successfully eradicated on a global scale, making it the first infectious disease to be wiped out by intentional human activity.

There were 285 new cases of measles in the U.S. in 2024. Measles, also known as rubeola, is an infectious disease that is highly contagious and affects mostly children. Common symptoms of measles include fever, runny nose, sore throat, cough, and a rash. Although death rates from measles have decreased around the world, it is still responsible for around 81,000 deaths worldwide per year. Measles vaccination The main reason for the decrease in measles cases and deaths is due to high vaccination rates. The widely used MMR vaccine protects against measles, mumps, and rubella and is safe and effective. In 2023, around 91 percent of adolescents in the U.S. aged 13 to 17 years had received an MMR vaccination. However, in recent years there has been a rise in measles cases in many parts of the world due to vaccine hesitancy. Vaccine hesitancy Vaccine hesitancy refers to a refusal or reluctance to have children vaccinated, despite the overwhelming evidence that vaccines are safe and effective. This hesitancy comes from a misunderstanding of the ingredients in vaccines and how they work, a mistrust of doctors and pharmaceutical companies, and belief in the unfounded associations of vaccines with other diseases and disorders.

IntroductionCOVID-19 vaccination has been a key intervention in reducing the severity of symptoms; however, concerns about vaccine safety, particularly regarding allergic reactions, arose early on. Healthcare workers faced the challenge of addressing these concerns to ensure safe vaccine administration. This study aimed to review the practical aspects of using allergy skin testing for COVID-19 vaccine excipients in patients with a history of allergic reactions developed following mRNA COVID-19 vaccination.MethodsA retrospective chart review was conducted for patients who reported allergic reactions after the COVID-19 vaccine and underwent allergy skin testing for COVID-19 vaccine excipients in the Adult Allergy and Immunology Service at Hamad Medical Corporation, Doha, Qatar. The testing protocol, developed based on published data during the pandemic, included skin prick (SPT) and intradermal (ID) testing using medications containing polysorbate 80 and polyethylene glycol (PEG), the primary excipients in the COVID-19 vaccines suspected of triggering allergic responses.ResultsOf the 88 patients reviewed, 38 reported different types of allergic reactions following mRNA COVID-19 vaccination, with the majority being female. Anaphylaxis was reported in 21.1% of the patients, while the remaining experienced less severe allergic reactions. All patients underwent SPT and ID testing with PEG and polysorbate 80. By SPT, two patients tested positive for PEG and none for polysorbate 80. By ID, seven tested positive for polysorbate 80 and one for PEG. Among patients who experienced anaphylaxis, 50% had positive allergy test results. Twenty-three percent of patients with negative test results could receive additional vaccine doses without adverse reactions.ConclusionManaging patients with a history of allergic reactions to the COVID-19 vaccine is challenging, as the exact mechanisms and accurate and valid allergy testing are yet to be determined. In our cohort, most patients had mild allergic reactions following vaccination. Excipients' allergy skin testing has helped to reduce vaccine hesitancy despite its questionable utility in clinical practice.

On March 10, 2023, the Johns Hopkins Coronavirus Resource Center ceased its collecting and reporting of global COVID-19 data. For updated cases, deaths, and vaccine data please visit: World Health Organization (WHO)For more information, visit the Johns Hopkins Coronavirus Resource Center.COVID-19 Trends MethodologyOur goal is to analyze and present daily updates in the form of recent trends within countries, states, or counties during the COVID-19 global pandemic. The data we are analyzing is taken directly from the Johns Hopkins University Coronavirus COVID-19 Global Cases Dashboard, though we expect to be one day behind the dashboard’s live feeds to allow for quality assurance of the data.DOI: https://doi.org/10.6084/m9.figshare.125529863/7/2022 - Adjusted the rate of active cases calculation in the U.S. to reflect the rates of serious and severe cases due nearly completely dominant Omicron variant.6/24/2020 - Expanded Case Rates discussion to include fix on 6/23 for calculating active cases.6/22/2020 - Added Executive Summary and Subsequent Outbreaks sectionsRevisions on 6/10/2020 based on updated CDC reporting. This affects the estimate of active cases by revising the average duration of cases with hospital stays downward from 30 days to 25 days. The result shifted 76 U.S. counties out of Epidemic to Spreading trend and no change for national level trends.Methodology update on 6/2/2020: This sets the length of the tail of new cases to 6 to a maximum of 14 days, rather than 21 days as determined by the last 1/3 of cases. This was done to align trends and criteria for them with U.S. CDC guidance. The impact is areas transition into Controlled trend sooner for not bearing the burden of new case 15-21 days earlier.Correction on 6/1/2020Discussion of our assertion of an abundance of caution in assigning trends in rural counties added 5/7/2020. Revisions added on 4/30/2020 are highlighted.Revisions added on 4/23/2020 are highlighted.Executive SummaryCOVID-19 Trends is a methodology for characterizing the current trend for places during the COVID-19 global pandemic. Each day we assign one of five trends: Emergent, Spreading, Epidemic, Controlled, or End Stage to geographic areas to geographic areas based on the number of new cases, the number of active cases, the total population, and an algorithm (described below) that contextualize the most recent fourteen days with the overall COVID-19 case history. Currently we analyze the countries of the world and the U.S. Counties. The purpose is to give policymakers, citizens, and analysts a fact-based data driven sense for the direction each place is currently going. When a place has the initial cases, they are assigned Emergent, and if that place controls the rate of new cases, they can move directly to Controlled, and even to End Stage in a short time. However, if the reporting or measures to curtail spread are not adequate and significant numbers of new cases continue, they are assigned to Spreading, and in cases where the spread is clearly uncontrolled, Epidemic trend.We analyze the data reported by Johns Hopkins University to produce the trends, and we report the rates of cases, spikes of new cases, the number of days since the last reported case, and number of deaths. We also make adjustments to the assignments based on population so rural areas are not assigned trends based solely on case rates, which can be quite high relative to local populations.Two key factors are not consistently known or available and should be taken into consideration with the assigned trend. First is the amount of resources, e.g., hospital beds, physicians, etc.that are currently available in each area. Second is the number of recoveries, which are often not tested or reported. On the latter, we provide a probable number of active cases based on CDC guidance for the typical duration of mild to severe cases.Reasons for undertaking this work in March of 2020:The popular online maps and dashboards show counts of confirmed cases, deaths, and recoveries by country or administrative sub-region. Comparing the counts of one country to another can only provide a basis for comparison during the initial stages of the outbreak when counts were low and the number of local outbreaks in each country was low. By late March 2020, countries with small populations were being left out of the mainstream news because it was not easy to recognize they had high per capita rates of cases (Switzerland, Luxembourg, Iceland, etc.). Additionally, comparing countries that have had confirmed COVID-19 cases for high numbers of days to countries where the outbreak occurred recently is also a poor basis for comparison.The graphs of confirmed cases and daily increases in cases were fit into a standard size rectangle, though the Y-axis for one country had a maximum value of 50, and for another country 100,000, which potentially misled people interpreting the slope of the curve. Such misleading circumstances affected comparing large population countries to small population counties or countries with low numbers of cases to China which had a large count of cases in the early part of the outbreak. These challenges for interpreting and comparing these graphs represent work each reader must do based on their experience and ability. Thus, we felt it would be a service to attempt to automate the thought process experts would use when visually analyzing these graphs, particularly the most recent tail of the graph, and provide readers with an a resulting synthesis to characterize the state of the pandemic in that country, state, or county.The lack of reliable data for confirmed recoveries and therefore active cases. Merely subtracting deaths from total cases to arrive at this figure progressively loses accuracy after two weeks. The reason is 81% of cases recover after experiencing mild symptoms in 10 to 14 days. Severe cases are 14% and last 15-30 days (based on average days with symptoms of 11 when admitted to hospital plus 12 days median stay, and plus of one week to include a full range of severely affected people who recover). Critical cases are 5% and last 31-56 days. Sources:U.S. CDC. April 3, 2020 Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19). Accessed online. Initial older guidance was also obtained online. Additionally, many people who recover may not be tested, and many who are, may not be tracked due to privacy laws. Thus, the formula used to compute an estimate of active cases is: Active Cases = 100% of new cases in past 14 days + 19% from past 15-25 days + 5% from past 26-49 days - total deaths. On 3/17/2022, the U.S. calculation was adjusted to: Active Cases = 100% of new cases in past 14 days + 6% from past 15-25 days + 3% from past 26-49 days - total deaths. Sources: https://www.cdc.gov/mmwr/volumes/71/wr/mm7104e4.htm https://covid.cdc.gov/covid-data-tracker/#variant-proportions If a new variant arrives and appears to cause higher rates of serious cases, we will roll back this adjustment. We’ve never been inside a pandemic with the ability to learn of new cases as they are confirmed anywhere in the world. After reviewing epidemiological and pandemic scientific literature, three needs arose. We need to specify which portions of the pandemic lifecycle this map cover. The World Health Organization (WHO) specifies six phases. The source data for this map begins just after the beginning of Phase 5: human to human spread and encompasses Phase 6: pandemic phase. Phase six is only characterized in terms of pre- and post-peak. However, these two phases are after-the-fact analyses and cannot ascertained during the event. Instead, we describe (below) a series of five trends for Phase 6 of the COVID-19 pandemic.Choosing terms to describe the five trends was informed by the scientific literature, particularly the use of epidemic, which signifies uncontrolled spread. The five trends are: Emergent, Spreading, Epidemic, Controlled, and End Stage. Not every locale will experience all five, but all will experience at least three: emergent, controlled, and end stage.This layer presents the current trends for the COVID-19 pandemic by country (or appropriate level). There are five trends:Emergent: Early stages of outbreak. Spreading: Early stages and depending on an administrative area’s capacity, this may represent a manageable rate of spread. Epidemic: Uncontrolled spread. Controlled: Very low levels of new casesEnd Stage: No New cases These trends can be applied at several levels of administration: Local: Ex., City, District or County – a.k.a. Admin level 2State: Ex., State or Province – a.k.a. Admin level 1National: Country – a.k.a. Admin level 0Recommend that at least 100,000 persons be represented by a unit; granted this may not be possible, and then the case rate per 100,000 will become more important.Key Concepts and Basis for Methodology: 10 Total Cases minimum threshold: Empirically, there must be enough cases to constitute an outbreak. Ideally, this would be 5.0 per 100,000, but not every area has a population of 100,000 or more. Ten, or fewer, cases are also relatively less difficult to track and trace to sources. 21 Days of Cases minimum threshold: Empirically based on COVID-19 and would need to be adjusted for any other event. 21 days is also the minimum threshold for analyzing the “tail” of the new cases curve, providing seven cases as the basis for a likely trend (note that 21 days in the tail is preferred). This is the minimum needed to encompass the onset and duration of a normal case (5-7 days plus 10-14 days). Specifically, a median of 5.1 days incubation time, and 11.2 days for 97.5% of cases to incubate. This is also driven by pressure to understand trends and could easily be adjusted to 28 days. Source