Fluenz Mandarin 1 2 3 [RePOST]
At this time, Section 2.59 of the New York State Sanitary Code (10 NYCRR 2.59) requires all health care and residential facilities and agencies regulated pursuant to Article 28, 36, or 40 of the Public Health Law to ensure that all personnel, as defined in the regulation, not vaccinated against influenza for the current influenza season wear a surgical or procedure mask while in areas where patients or residents are typically present.
Fluenz Mandarin 1 2 3 [RePOST]
The overall burden of influenza (flu) for the 2019-2020 was an estimated 36 million flu-related illnesses, 16 million flu-related medical visits, 390,000 flu-related hospitalizations, and 25,000 flu-related deaths (Table 1).
Two main types of influenza vaccines are currently available: parenteral inactivated influenza vaccines and intranasal live attenuated vaccines. Both display a good safety profile in adults and children. However, they can cause adverse events and/or rare adverse events, some of which are more prevalent in children, while others with a higher prevalence in adults.
The safety and reactogenicity of QIV have proved similar to those of seasonal influenza vaccines, as demonstrated by Tinoco et al.36 The most common adverse reactions were pain at the injection site, headache and myalgia, all of which disappeared within 3 days of vaccination. No serious AE or death were registered.
Severe consequences have rarely been reported, and have displayed a similar frequency after LAIV, TIV and placebo; no association with vaccine administration has been proved. Recently, McNaughton's group investigated the incidence of adverse effects of interest (AEIs) in children and adolescents upon immunization with nasal QLAIV (Fluenz Tetra, Astra Zeneca) in the same influenza season in England. They reported nasal congestion, cough and malaise among the most frequent AEIs. No serious AE, hospitalization or death was reported during the investigation.57
In the US, the prevalence of asthma66,67 and egg allergy68 has prompted vaccine manufacturers to tackle the problem of immunizing egg-allergic patients in whom vaccination with egg-containing influenza vaccine is recommended.
In the 1970s, egg-allergic patients had to undergo skin testing with the influenza vaccine69-71; if the result was negative, they could be safely immunized, otherwise vaccination was not recommended. However, a subsequent study conducted by Murphy and Strunk72 found that influenza vaccination was safe even in the event of a positive skin-test result if a protocol of multiple, graded injections was implemented, whereas Zeiger73 suggested that influenza vaccine skin tests (prick and intradermal) should be carried out before vaccine administration in individuals with a history of adverse reactions to eggs and positive skin-test results. A single dose could be administered if the influenza vaccine skin-test results were negative, while a 2-dose graded or desensitization protocol should be implemented if they were positive.73,74 The safety of administering the influenza vaccine in a graded 2-dose fashion to egg-allergic children without performing the vaccine skin test was investigated by Chung and coll.75 in a retrospective chart-review study, which suggested that the skin test could safely be omitted.
Recent epidemiological investigations have confirmed the association between an AS03-adjuvanted pandemic influenza vaccine (Pandemrix, GlaxoSmithKline Biologicals, Germany) and the onset of narcolepsy in children and adolescents.92 The novel circulating A(H1N1) influenza virus was identified in April 2009 and quickly spread worldwide in June 2009. Millions of A(H1N1) pandemic vaccine doses were produced within a narrow time-window (from April 2009 until November of the same year). One year after the European AS03-adjuvanted A(H1N1) pandemic vaccine was authorized in Europe, a higher number of narcolepsy cases was observed in Sweden and Finland (9.0/100,000 incidence in vaccinees versus 0.7 in unvaccinated subjects),92-95 and also in other countries.11,96 It was hypothesized that a peptide located on a surface-exposed region of influenza nucleoprotein A was characterized by protein residues similar to the first extracellular domain of hypocretin (HCRT) receptor 2. In accordance with this hypothesis, a higher frequency of antibodies to HCRT receptor 2 was found in sera from narcoleptic Finnish patients immunized with the European AS03-adjuvanted vaccine Pandemrix92 than in unvaccinated subjects. Furthermore, a cross-reaction between HCRT receptor 2 and influenza nucleoprotein was described. No persistent antibody response to nucleoprotein was detected in sera from non-narcoleptic subjects vaccinated with Focetria (a vaccine differently produced), which contained 72.7% less influenza nucleoprotein. Thus, differences in vaccine nucleoprotein content and the respective immune response could explain the correlation between narcolepsy and Pandemrix.97
Esposito et al.113 evaluated the safety and reactogenicity of intradermal (ID) influenza vaccine, an alternative route of injection to the traditional intramuscular (IM) modality, in children older than 3 years. Although local reactions were more common in the cohort of ID vaccinees than in the IM vaccine group, they were transitory and did not become more frequent as the vaccine dose increased.
Vaccination remains the most effective strategy for preparing for seasonal infections and for a possible pandemic. The WHO guidelines state that, whenever possible, the safety of pandemic vaccines should be evaluated before the pandemic. However, the safety profile of a pandemic influenza vaccine may not be completely investigated.80,125
Several studies have evaluated the safety profile of egg/cell-derived, adjuvanted/non-adjuvanted influenza TIV and QIV in adults and elderly subjects. Overall, the vaccines showed a robust safety profile and acceptable reactogenicity. Injection-site pain is the most frequently reported local symptom (Table 3).31,136,138-143 The most frequent systemic reactions in both adults and the elderly are fatigue, headache and myalgia (Table 3).31,136,140-146 Only one study reported fever as the most common solicited reaction.139 Rates of solicited local and systemic reactions are higher in adults than in the elderly31,139,141,142,145,147,148 and in females than in males.145 Unsolicited AEs are nasopharyngitis and cough.31,136,138,146 Overall, no serious AEs or deaths related to influenza vaccination are reported31,142,143,145,146,149 with the exception of two studies. The first of these136 described serious AEs in the QIV group (myocardial infarction and cerebrovascular accident) and the TIV group (pneumonia, cerebrovascular accident, nephrolithiasis and arteriosclerosis). The second138 reported one death, possibly related to vaccination, and SAEs (bronchitis, asthmatic crisis, chronic obstructive pulmonary disease and GBS) possibly or probably related to vaccination with TIV, with and without adjuvant.
Several studies have evaluated the safety profile of seasonal and pandemic influenza vaccines in high-risk individuals and have shown that vaccines are well tolerated and safe in this target group.27,152,171-176 However, the conventional vaccines are reported to induce a poor immune response in high-risk individuals, and different strategies, such as administration of a high-dose booster, the use of adjuvants and ID administration, have been evaluated.173
Overall, influenza vaccines are very safe186 and well tolerated in most age-groups and formulations. Admittedly, they can cause AEs and/or rare AEs, some of which are more prevalent in children, while others are more prevalent in adults. However, symptoms due to AEs, such as rhinorrhea or congested nose, are usually transient. Severe allergic reactions to influenza vaccines are very rare, being estimated at less than 1 in a million doses.187
Another critical factor is that the currently available influenza vaccines are not well suited for use in low and middle-income countries (LMIC),188 the health systems of which often lack the resources to implement vaccination adequately. Indeed, the WHO standards concerning the programmatic suitability of vaccines are not met by many influenza vaccines in LMICs. In these conditions, the priority target group is that of young children (
Further studies of all influenza vaccines, involving follow-up periods to bring to light possible increases in hospitalization, should be conducted on children
For example, influenza vaccines are usually only partially effective(particularly in the high-risk groups targeted such as older people) andchanges to the circulating virus renders the immunity useless after atime, so annual re-vaccination is required. However, even partialprotection can have important benefits, with for example the FluEnznasal spray vaccine not only reducing disease in children but alsoreducing spread of disease to their older relatives.
To address gaps in understanding of protective immunity and to develop astrategy for selecting or rejecting vaccine candidates, human infectionchallenge with SARS-CoV-2 is being considered57 (Appendix 1). Human infectionchallenges with influenza and other respiratory viruses have beenconducted safely for many decades and have provided critical knowledgefor the development of vaccines. By deliberately inoculating volunteerswith a well-characterised virus, a consistent and guaranteed highinfection rate is achieved so fewer participants are required to showevidence of protective efficacy. Vaccine testing therefore avoidsrelying on exposure of individuals to natural infection in thecommunity, which may be limited or unpredictably variable. Using a humanchallenge system, candidate vaccines can be quickly assessed for theimmunity they elicit and whether that affects the infection rate. In thecase of SARS-CoV-2, the novelty of the virus and uncertainties abouteffective treatment or long-term complications require carefulconsideration to balance the risks to individual volunteers and benefitto society in accelerating the development of effective vaccines,especially when field trials using community exposure are still possiblealbeit only in some places.58 59 60The WHO has published an ethical framework for SARS-CoV-2 challengestudies and a number of groups are considering strategies to mitigaterisk. Specifically, COVID-19 is now known to cause mild or asymptomaticdisease in the vast majority of young adults, so restricting the agerange of enrolled volunteers and limiting disease with antivirals mayrender the system safer. This is clearly a limitation in that vaccinescannot be tested in groups such as the older people in whom the risks ofchallenge are higher. Furthermore, challenge studies do not tell usabout the effectiveness of a vaccine programme in the real world. Keysteps to developing this model will be to generate a stock of SARS-CoV-2that is suitable for administration to volunteers; expert consensus onhow such studies should be run safely; and identification of thefacilities and resources to conduct the studies while minimising risk tostudy participants and people in the surrounding community to anacceptable level.