the polio vaccine increased even further. this act embodied three of the most important pillars of a behavioral change campaign: social influence, social norms and examples. elvis presley used his social influence to normalize getting the polio vaccine, which increased vaccination rates among american youth to over 80% in just under 6 months. these types campaigns were the heart of the mass vaccination efforts in america. barriers to eradication despite the global efforts to vaccinate and eradicate polio, the virus still causes outbreaks every year. as of 2021, only wild polio virus type 1(wpv1) affects the world and are localized in afghanistan and pakistan. the circulating vaccine-derived poliovirus (cvdpv) caused outbreaks in 32 countries in 2020. the cvdpv is a result of live oral poliovirus vaccine becoming infectious after extended circulation. this prompted an update to the global polio eradication initiative (gpei) strategy for the years 2022–2026. with the most recent update in august 2020, the who african region was declared polio free leaving only one of the six who regions with polio. the gpei's new initiatives focused on eradicating the wpv1 in both afghanistan and pakistan while also combating the new outbreaks of cvdpv. the difficulty arises when the world must not only eliminate the wild type polio virus but also the vaccine-derived form, making eradication even more complex. while both the live and inactivated polio vaccines were wildly successful in saving the world from the historic endemic, there still are drawbacks with each of the vaccines. the opv vaccine was reverted to an infectious strain which led to the rise of the cvdpv. while the inactivated polio vaccine (ipv) protected the host, it was not strong enough to generate intestinal mucosa immunity and therefore did not prevent the transmission of the virus. these weaknesses suggest that more innovative vaccines or a combination of the two is needed to completely eradicate polio. swine flu vaccination in 1918, the deadly h1n1 influenza virus which infected approximately 500 million people around the world and resulted in the deaths of 50 to 100 million people (3% to 5% of the world population). new york city had created two major mass immunization programs, the first was the smallpox immunization program initiated in 1947 and the second was the swine flu influenza program in 1976. for the first mass immunization campaign in 1947, the new york city department of health maintained the outbreak within a period of 29 days and vaccinated 6.35 million people successfully. weinstein and colleagues established vaccination clinics at many locations such as at the department of health's 125 worth street headquarters, at the 21 district health centers, 60 child health clinics, and 13 municipal hospitals in order to accommodate for the high demand of people requesting for a vaccination. the smallpox vaccination effort was announced to be officially terminated on may 3, 1947. in which case, it was rather surprising to see that the second mass immunization campaign in 1976, which was a national immunization effort, was only able to accomplish vaccinating 639,000 against swine influenza over a period of 60 days. it was also noted that in 1976, the mass swine flu vaccination programme was discontinued after 362 cases of guillain–barré syndrome were identified among 45 million vaccinated people. the vast differences between the number of people vaccinated in 1947 versus 1976, despite the outbreaks, are reflected mainly by the public's skeptical perception of the minimal severity and low threat of swine flu. swine flu, also known as h1n1 influenza a virus, is a type of infectious respiratory disease that has caused high economical and medical burden every year around the world. there are important lessons to be learned from the recent 'swine flu' pandemic. improving techniques are necessary in trying to decrease the spread of infection-both in the community and within our hospitals would mean improving infection control and hygiene, and the use of masks, alcohol hand rubs and so on. a worldwide study was conducted which comprehensively analyzed adamantanes resistance in h1n1 influenza viruses from 1918 to 2019 and showed 77.32% h1n1 influenza variants demonstrating resistance to adamantanes. this study emphasizes the importance of global surveillance, especially in many third-world countries, as well as the evolution of drug-resistant h1n1 influenza variants in an effort to prevent another pandemic. contemporary usage covid-19 the introduction of multiple covid-19 vaccines throughout the pandemic such as pfizer, moderna, johnson and johnson, and the newly approved novavax vaccine have helped allow large amounts of the population to get vaccinated. when covid-19 was identified in december 2019 there were no vaccines readily available to vaccinate mass populations. by december 2020, the pfizer vaccine was the first to receive emergency use approval by the food and drug administration. vaccines under normal circumstances can take up to 10–15 years to be made and approved. without worldwide collaboration, funding for research, and rigorous guidelines for clinical trials there would not have been a quickly developed vaccine. covid-19 vaccines the type of vaccines that are available are messenger rna, vector, and protein subunit. messenger rna vaccines work by giving cells specific instructions to make the s protein found on the surface of the covid-19 virus. it does not infect recipients of the vaccine with the virus but allows for the body to detect and fight the covid-19 virus. both pfizer and moderna covid-19 vaccines fall in to the messenger rna category. vector vaccines also deliver instructions on how to make the s protein found on the surface of the virus. it also does not cause the recipient to become infected with the virus after vaccination. the johnson & johnson vaccine falls into the vector category. lastly the subunit vaccine only contains a part of the virus needed to create an immune response. the s protein is the harmless subunit that will allow for an immune response when the covid-19 virus is detected. the novavax vaccine falls into the subunit protein category. when vaccinating large populations an action plan must be created to organize which groups will receive the vaccination first. the california department of public health created an action plan to vaccinate by population group. first immunocompromised groups, second unvaccinated or not fully vaccinated, third under 12 populations, fourth boosters for those 65 and older, and lastly boosters for ages 12–64.a mass vaccination site at a stadium in salisbury, maryland as well as mass vaccination centers being established at many locations, such as stadiums led to many people getting vaccinated. in the united states, nfl commissioner roger goodell offered the league's 30 stadiums as mass vaccination sites. as of april 2021, nfl stadiums have administered more than 2 million doses. by december 2021, more than 100,000 people had received vaccinations at indianapolis motor speedway. pharmacist have also played an important role in getting mass populations vaccinated since they are a skilled and trained workforce able to help increase vaccination rates. many people can turn to drug or convivence stores to get vaccinated since it can be a quick and easy place to access. pharmacies have played a large roll in mass vaccination now more than ever due to the pandemic. some states prior to the pandemic did not allow pharmacist to vaccinate or administer flu vaccines. now, pharmacies are contracting with state and federal governments since they have become key players in vaccinations. without the involvement of pharmacies mass vaccination would be difficult to achieve. in most communities 90% of people live within five miles of a pharmacy. pharmacist can oftentimes be the quickest access to a healthcare provider, making it a desirable option for the public to come and get vaccinated. not only have pharmacist been involved in covid-19 vaccinations but pharmacy technicians as well. pharmacy technicians have helped alleviate the workload on pharmacist with the large increase in demand for vaccinations. they also can create more opportunities to interact with people who are hesitant in getting the covid-19 vaccines. pharmacy technicians can support pharmacist which will allow more vaccination services to be accommodated efficiently and safety. these efforts will allow for an increase in vaccinations and help vaccinate large groups at a time. during the pandemic pharmacist have had a fundamental roll in sharing information about covid-19 vaccines. pharmacist are a quick resource for information and can help relieve some common concerns about reactions or misinformation to the vaccines. they are also advocates for getting vaccinated since they are educators and vaccine administrators. sharing information to the public about covid-19 vaccines can help increase vaccinations rates. since pharmacist are easily accessible in the community setting they can help motivate or encourage getting vaccinated helping decrease preventable infections or diseases such as covid-19. mass vaccination of covid-19 vaccines is important to help stop the spread of the coronavirus and eventually end the pandemic. individual governments have been allocating billions of dollars to increase production of vaccines to help with the current global manufacturing need of vaccines. countries such as the united states, canada, and australia were able to receive many vaccines early on due to them being wealthier countries. they were able to receive many doses enough to vaccinate their own countries but this left other lower-income countries with limited supply of the vaccines. with some countries receiving more vaccines than others this leads to inequitable distribution and can increase the risk of new outbreaks. without proper global vaccine distribution it will make it more difficult to end the pandemic and allow for mass vaccination as a global effort. amid the new strains of the coronavirus such as the omicron variant, scientist and healthcare officials have raised concern about reduced effectiveness of available vaccines. in response to a concern about vaccines having reduced effectiveness countries have encouraged booster shots for most of their population. the world health organization would like to prioritize unvaccinated people over booster doses so more of the population will have received their initial dose.