Flu Vaccines: Technology Developments and Effects

Flu Vaccines: Technology Developments and Effects Flu, also known as Influenza, is a contagious viral disease that affects the respiratory system. It is caused by influenza viruses. It is highly infectious unpredictable disease that spreads though secretions of nose and lungs. Flu causes mild to severe illness and sometimes even leads to death. According to U.S. CDC, in an average year, 5 to 20 percent of the U.S. population gets the flu, more than 200,000 people are hospitalized with seasonal flu-related complications and about 36,000 people die from flu-related causes.  [1]   Flu vaccination is one of the best ways to protect the community from the seasonal and pandemic flu effects. Pandemic flu is different from seasonal flu,  [2]  it is a global disease outbreak that usually occurs when a flu strain new to humans emerges and causes widespread illness. The pandemic flu is very dangerous because of newly originated strain to which humans have little pre-existing immunity and vaccines would probably not be available immediately in early stages of pandemics.2 The pandemic outbreaks have potential impact on society causing high levels of illness, death, economic loss and social disruption. Recently in 2009 a novel H1N1 virus emerged which became pandemic. It is estimated that in U.S., approximately 43-89 million persons became ill because of this pandemic H1N1. It also resulted in deaths among children, adults, pregnant and post-partum women. On the other hand seasonal flu form occurs seasonally, usually in winter. Seasonal flu causes significant illness and in some cases death. Annual vaccination: Flu vaccination is most effective way to control and prevent influenza virus infections and severe complications. It is especially important for younger children and people who are at high risk of catching infections. Flu vaccines are available as Flu shot of trivalent inactivated or killed virus (TIV) or Live Attenuated Influenza Vaccine (LAIV) as nasal spray. However, it is impossible to prevent influenza by one time vaccination because Influenza viruses undergo changes from year to year and develop resistance making previously available vaccines ineffective. Therefore scientists make different flu vaccine every year. In addition the immunity developed from having the flu caused by one strain does not always offer protection against new strain. Immunity also declines over time after previous years vaccination and at a point it may be too low to provide protection after year. Hence to combat with changing influenza viruses, vaccination is done every year. Getting seasonal flu vaccin ation offers protection that lasts throughout the year preventing infection and its complications. Vaccine recommendations: The World Health Organization organizes meetings twice a year and recommends inclusion of specific virus strains in Influenza vaccine based on results of surveillance, laboratory and clinical studies, and the availability of vaccine virus strains. Then individual countries make their own decision about inclusion of virus strains in vaccines licensed in their country. In U.S., each year, a panel of experts from agencies such as the FDA and the CDCs Advisory committee on Immunizations Practices (ACIP) studies the available data and decides which three strains of influenza viruses will most likely be active during the next flu season. The selection of vaccine strains for inclusion in seasonal flu vaccine is based on circulating virus strains, how they are spreading, and how well current vaccine strain protects against newly identified strains.  [3]  The ACIP makes written recommendations for administration of vaccines to children and adults. These recommendations include age for administration, doses, dosing interval, precautions and contraindications.  [4]  The seasonal flu vaccine for 2010-2011 offers protection against H3N2 virus, an influenza B virus and pandemic H1N1 virus that emerged in 2009. Vaccine Shortage Issue: There are many issues related to flu vaccines. Among many vaccine shortage is the most noticed every year. A close examination reveals that the shortage for vaccine is not one cause but several. Some of them include high risk of contamination in vaccine production, unpredictable consumer demand, and low profits along with lack of liability protection from costly lawsuits made many manufacturers out of flu vaccine business.  [5]   Most of the companies stopped production of flu vaccine because the demand varies from year to year, as it is always unpredictable and once flu season passes away the remaining stock is useless because a new vaccine is required to deal with changing strains of virus  [6]. According to 2003 report by Institute of Medicine, a unit of National Academy of Sciences, the companies producing vaccines dropped from 30 to 5 in year 2004.6 The companies producing injectable influenza vaccine dropped to two (Chiron Aventis Pasteur) in year 2005.5 Production of flu virus vaccine is very complicated and expensive, but the government keeps price of flu vaccine low. Among the two firms Chiron was forced to shut down its UK plant because of quality control reasons. This resulted in shortage. Another problem is that each year, the U.S. Food and Drug Administrations Vaccines and Related Biological Products Advisory Committee meets in spring identifies the flu virus strains to be protected by flu vac cine manufactured for that fall-winter flu season.5 This time gap between committees decision and following flu season allows manufactures to make vaccines but the flu strains can undergo changes by the time vaccines are manufactured for flu season. Thus it is difficult to determine for what strains of flu virus vaccine should be made which may end up with vaccine shortage for specific flu season. In 2003 committee voted to include the Panama flu virus in vaccine for the 2003-04 flu seasons, excluding Fujian flu mutant virus, a more virulent but less prevalent at that time. But the winters flu outbreak consisted almost entirely of the Fujian strain. CDC without noticing it recommended widespread vaccination which did not protect the public against the prevalent flu strain. The CDC later admitted the vaccine had no or low effectiveness against ILI (influenza-like illness). Latest development in flu vaccine research: The outbreak of pandemic flu has motivated increase in flu research The recent advancement in field of flu vaccine research is development of Universal flu vaccines. Scientist Dr. Sarah Gilbert and team at Oxford Jenner Institute developed universal flu vaccine that target proteins inside flu that are common across all strains and tested on humans infected with flu  [7]. Gilbert used 11 healthy volunteers for her study and vaccinated and then infected them along with 11 non-vaccinated volunteers. Upon careful monitoring there has been dramatic increase in T-cell count in vaccinated subjects which play important role in producing immune response, protecting against viral infections. Researchers of University of Adelaide, Dr. Darren Miller and his colleagues, have trialled a universal synthetic flu vaccine in mice which is another step closer to development of a universal flu vaccine. It is derived synthetically which does not require annual reformulation which would be advantageous to control and prevent flu. Dr. Miller used specific peptides derived from noses of mice to trigger an immune response to a tiny region of flu virus that is present in all influenza A and B viruses, which effectively neutralizes the virus.  [8]   The studies have shown that test vaccine provided mice with 100% protection against a laboratory strain of H3N2 and 20% protection against a highly pathogenic bird flu virus.8 This positive response provides scope for further laboratory and clinical testing. Economics of Flu vaccination: Economic studies indicate that flu vaccination reduces healthcare, societal, and individual costs and also productive losses associated with influenza illness.  [9]  A study of a larger population comparing persons aged 5064 years with those aged à ¢Ã¢â‚¬ °Ã‚ ¥65 years estimated the cost-effectiveness of influenza vaccination to be $28,000 per QALY saved (in 2000 dollars) in persons aged 5064 years compared with $980 per QALY saved among persons aged à ¢Ã¢â‚¬ °Ã‚ ¥65 years (393).Two studies in the United States indicated that vaccination can reduce both direct medical costs and indirect costs from work absenteeism and reduced productivity (79,394). Latest flu pandemics and their effect on the Regulatory world: The pandemic flu is unpredictable, spreads rapidly world wide affecting large proportions of the human population. There have been three influenza pandemics of which the recent one was the 2009 flu pandemic. This occurred first in Mexico, March 2009 caused by pandemic H1N1/09 virus also referred to as swine flu. It is subtype of Influenza A virus. On 10th of August 2010, the Director General of WHO announced that H1N1 pandemic virus has moved into post-pandemic period.  [10]  CDC estimated that nearly a 1 million cases of 2009 H1N1 pandemic flu had occurred in United States. The pandemic H1N1 flu cases doubled in many countries from mid-June 2009 to early July 2009. According to WHO statistics, 18,000 deaths were reported because of H1N1. This outbreak resulted in extraordinary illness throughout the world with increased demand for vaccination against the swine flu virus in a short time. The pandemics put intense burden on the regulatory authorities as vaccines have to be made available globally to meet the increased demands. Regulatory agencies adopted procedures for accelerated approval of vaccines against swine flu. In U.S., FDA expanded its capacity to expedite development, evaluation and licensing of additional flu vaccines and manufacturing facilities to meet pandemic preparedness needs  [11]. CBER has issued guidelines encouraging vaccine manufacturers to explore cell-culture and recombinant techniques, and to incorporate biological integrators, such as immune response, into their product-development designs.  [12]  The outbreak of pandemic flu also has increased collaboration among foreign regulatory agencies to share vaccine safety information and experiences and mount a coordinated response to the emer gency. Beta Lactam Antibiotics: Examples and Uses Beta Lactam Antibiotics: Examples and Uses The beta-lactam antibiotics for their extensive scale of actions are preferred most among antimicrobial factors. The penicillins and cephalosporins are the two categories of this ÃŽ ² lactam antibodies that are extraordinarily less toxic to organisms.(1) At present ,the ÃŽ ²-lactam groups of antibiotics are the highest frequently used universal antibiotics .(2) Cellular membrane of most bacteria enclosed by a cell wall but an extra outermost layer seen on some of them. The periplasmic space in gram negative bacteria is the cavity in the middle of the cell membrane and the cell wall. Periplasm instead of a clearly defined periplasmic space is retained by most gram positive bacteria .(3) But peptidoglycan is the greatest significant element of the cell wall that linked as a new cell by way of the metabolic absorption in periplasm is a polymer made of N-acetyl muramic acid alternating with N-acetyl glucosamine.Arises of the bacterial cell that is actually a process of peptidoglycan synthesis where accumulation of 5 amino acids to N-acetyl muramic acid is one of the leading phases. A precursor of peptidoglycan that conducted by a cell wall acceptor crossway the cell membrane in the periplasm and developed by linking N-acetyl glucosamine to the N-acetyl muramic acid . Generous crosslinking occurs for two key enzymes (trans peptidase and D-alanyl carboxypeptidase) and for the capacity to bind penicillins and cephalosporins, they are recognized as the penicillin binding proteins. B4 Development of cell wall by cross linking of a number of films of peptidoglycan grounds numerous layers and a much denser cell wall in gram positive bacteria than gram negative bacteria. Beta-lactam ring attach enzymes to cross-link peptidoglycans, that is a chemical structure which is available in the beta-lactam antibiotics consist of all penicillins and cephalosporins. Synthesis of bacterial cell wall is prevented by the affect of beta-lactam when transpeptidase and D-alanyl carboxypeptidase enzymes are attaching there by means of cross-linking and cause deterioration of bacterial cell wall.b5 As a bactericidal agents the antibiotic-penicillin binding protein complex of beta-lactam antibiotics excites autolysin discharge that have the capability of digest cell wall that left after bursting a cell. Generally, excessive inner osmotic pressure possessed by gram positive bacteria and in a low osmotic pressure enclosed atmosphere , cells those are lack of a usual and rigid cell wall are burst out.b6 There are many different types of methods of that bacteria became reistance to beta-lactam antibiotics. Transformation is one of the most important mechanisms among them and in the mean time of this process transfer of chromosomal genes between bacterium happens. Due to the death of a a resistance gene in a bacterium releasing of naked DNA in surrounding environment happens. a process known as homologous transformation and by this method the resistance gene in the host bacteria transferred from the naked DNA to the chromosome. the segment of the host DNA have been remodelled by resistance genes results altered penicillin binding proteins production by coding for cross-linking enzymes. But still cross linking of the peptidoglycan layers of the cell wall happens due to these altered penicillin binding proteins and reduces affinity for beta-lactam antibiotics and the bacterium became resistance. In penicillin-resistant S. pneumonia, this process caused the acquirement of genes from othe r naturally arising penicillin-resistant Streptococcus species. Bacteria grow into resistant to beta-lactam antibiotics by one more significant system is by the construction of enzymes capable of deactivating or altering the drug formerly it has a chance to apply its outcome on the bacteria.   peni The first human gammaretrovirus that is Xenotropic murine leukemia virus-related virus (XMRV) and responsible for chronic fatigue syndrome and prostate cancer (PC) have been revealed in recent times. Gammaretroviruses family is famous for their capability to activate cancer in the infested hosts. Analyzing study showed that vaccine-induced XMRV Env -specific binding and neutralizing antibodies (NAb) titers had limited span but highly changeable. in antibody levels, the different incidence stated for XMRV in a number of prostate cancer and chronic fatigue syndrome cohorts can be explained by the reasonably fast diminution . (2) Monoclonal antibodies (mAbs) have exceptional therapeutic applications in ophthalmology and can be used therapeutically by binding to molecular objects with high specificity. Tumour necrosis factor (TNF), epithelial growth factor receptor, vascular endothelial growth factor (VEGF) receptor, basic fibroblast growth factor receptor, platelet-derived growth factor, and cluster of differentiation antigens repressed by a number of single-agent therapies. Existing and future mAbs in contrast to different cytokines were evaluated for ocular disease treatment and two anti-VEGF mAbs( bevacizumab and ranibizumab), and three anti-TNF agents (infliximab, etanercept, and adalimumab), instruct ocular neovascularization and intraocular inflammation. Other mAbs showed positive results for ocular lymphoma or ocular inflammation but Ranibizumab is the only FDA-approved therapy. Intravenous application of mAbs has established satisfactory toxicity profiles, while intraocular injection may decrease the chances of systemic complications . To develop the excellence and extent of responses is the challenge for the future by merging biologic therapies while lessening side effects. 2i Leading causes of death in the world for coronary syndromes, stroke and other ischaemic arterial diseases . Therapy involves with medical actions correlating thrombolysis, antiplatelet drugs, and the re-opening of the coronary artery by angioplasty. In ischaemic cardiovascular diseases, platelet initiation is a acute phase . Chimeric Fab, c7E3 or abciximab is the only one recombinant antithrombotic antibody currently used in therapy and obstructs the ultimate phase of platelet aggregation. Subendothelium matrix activation by other platelet receptors have been recognized as prospective targets for the improvement of antithrombotic antibodies .2ii In drug development, insulin-like growth factor receptor I (IGF-IR) is becoming an attractive target. IGF-IR owed confined homology to insulin receptor and its specificity permits to distinguish between the two receptors. Recently there are some ongoing on IGF-IR and ongoing clinical trials on anti-IGF-IR monoclonal antibodies and combined treatments. 2iii