Swine-flu Vaccine: A Ray Of Hope
By Sheikh M Ashraf
29 June, 2010
Countercurrents.org
Influenza A virus has always created huge threats and massive losses to mankind. There have been 10 pandemics of influenza A in the past 300 years. An analytical study from the New England Journal of Medicine has showed that the pandemic of 1918 and 1919 killed 50 million to 100 million people, and although its severity is often considered anomalous, the pandemic of 1830 through 1832 was similarly severe as it simply occurred when the world's population was smaller. The three pandemic viruses that emerged in the 20th century — the 1918 ("Spanish influenza") H1N1 virus, the 1957 ("Asian influenza") H2N2 virus, and the 1968 (" Hong Kong influenza") H3N2 virus — all spread rapidly around the world, but only the 1918 virus was associated with mortality measured in the thousands per 100,000 population. Today, with a world population of over 6.5 billion, more than three times that in 1918 even a relatively "mild" pandemic could kill many millions of people. It is sobering to realize that in 1968, when the influenza pandemic occurred, the human, pig and bird population was much less than today. Given this reality, as well as the exponential growth in foreign travel during the past 50 years, and changing nature of influenza virus, we must accept that pandemic can emerge at any time, although we have face the swine flu pandemic last year killing on an average over 1500 people across the country. As per Press Information Bureau release from the ministry of health and family welfare ( 24th May 2010 ) deaths due to swine flu were 1527. Till date (24th May 2010), samples from 140055 persons have been tested for Influenza A H1N1 in Government Laboratories and a few private Laboratories across the country and 31904 (22.77%) of them have been found positive. It was the spring season of 2009, when the outbreak of H1N1 virus in the USA and Mexico suddenly showed its ugly head, and people in India were screened coming from the affected countries at airports for swine flu symptoms. The first case of the Swine flu in India was found on the Hyderabad airport on 13 May 2009 , when a man traveling from US to India was found H1N1 positive. Subsequently, more confirmed cases were reported and as the rate of transmission of the flu increased in the beginning of August, with the first death due to swine flu in India in Pune, and panic began to spread. Experts assume the virus "most likely" emerged from pigs in Asia , and was carried to North America by infected persons. The virus typically spreads from coughs and sneezes or by touching contaminated surfaces and then touching the nose or mouth. Symptoms, which can last up to a week, are similar to those of seasonal flu, and may include fever, sneezes, sore throat, coughs, headache, and muscle or joint pains. Maximum cases affected were from Maharashtra and maximum deaths were from Delhi . Our state has laboratory documented 99 cases of Swine flu and one death.
Swine flu is primarily a respiratory disease of pigs caused by influenza type A virus (H1N1 sub type) causes regular outbreaks in pigs and has potential to get transmitted from person to person. The symptoms of swine flu in people are similar to the symptoms of regular human flu like: fever, cough, sore throat, body/ joint aches, headache, chills, fatigue and occasionally diarrhea, vomiting, pneumonia and respiratory failure. It is more harmful for those who have chronic medical illnesses. Spread mainly from person to person in same way as for other types of influenza i.e. by droplet infection or droplet nuclei created by coughing, sneezing and talks of people with influenza or touching something with live flu viruses on it and then touching their mouth or nose. The entry of virus is respiratory tract.
Prevention and precautions:
Infected people may be able to infect others beginning one day before symptoms develop and up to 7 days or more days in case of children. People with swine influenza virus infection should be considered potentially contagious as long as they are symptomatic. Viruses and bacteria can live at least two hours or longer on surfaces like table surfaces, doorknobs, and desks, hence forth it is recommended to have frequent hand washing to reduce the chance of getting the infection. It is advisable to cover the nose and mouth with a handkerchiefs or tissue during coughing or sneezing, and avoid touching eyes, nose or mouth. Apart from avoiding close contact with sick people, movement should be restricted during the sickness period and contacts should be minimized. Washing hands for 15-20 seconds with soap and water or clean with alcohol-based hand cleaner, after having hands contaminated, will help protect from germs. If using gel, rub your hands until the gel is dry. The gel doesn't need water to work; the alcohol in it kills the germs on your hands. Swine flu infected people should stay home and avoid contact with other people as much as possible to keep from spreading the illness to others.
Warning signs that need urgent medical attention in children are : fast/labored breathing, feed refusal, drowsiness, irritability, bluish discoloration of skin and mucus membranes, flu-like symptoms improve but then return with fever and worse cough, fever with rash. While in adults , emergency warning signs are: difficulty breathing or shortness of breath, sudden progressive lethargy, confusion, pain or pressure in the chest or abdomen, intractable vomiting. It is important to know that surfaces like bedside tables, surfaces in the bathroom, children's toys, phone handles, cell phones and doorknobs should be cleaned by wiping them down with a household disinfectant according to directions on the product label. Linens, eating utensils, and dishes belonging to those who are sick do not need to be cleaned separately, but importantly these items should not be shared without washing thoroughly first. Eating utensils should be washed either in a dishwasher or by hand with water and soap.
Vaccination against Swine-flu:
All attempts to control influenza pandemics has so far met with little success and prospects of achieving good control remain poor. It was policy of Union Health Ministry's to vaccinate the health workers who were managing H1N1 cases in 2009 swine flu pandemic, and it was Penenza vaccine imported from France , supplied by Sanofi Pasteur that was used.
Now the indigenously developed vaccine (Vaxiflu-S) against H1N1 sub type of influenza virus A, manufactured by Ahmedabad based pharma major, Cadila Healthcare was launched by Ghulam Nabi Azad Union Minister for Health and Family Welfare on 4th June 2010.This egg based, inactivated vaccine based on conventional technology has been developed by the group's experts at its Vaccine Technology Centre (VTC), Ahemdabad. It will not be an over the counter drug and will be given only against prescription. The vaccine, has a shelf life of a year from date of manufacture, will provide protection only for one year. This vaccine can be used only by people aged between 18-60 and can't be used on small children or pregnant women who are believed to be at high risk of getting infected. Also, the inactivated vaccine is egg-based and cannot be used by those allergic to eggs. However, the vaccine has been found to be effective and safe with minor side-effects like pain in the area of administration. In view of changing antigenic characteristics of the virus (antigenic drift and antigenic shift), new vaccines are constantly required for combating the influenza pandemics, and time will only decide the fate of this newly launched vaccine, which supposedly will show promising results. This vaccine is priced at Rs.350/= and hopefully may be at cheaper rates once the competitors will be available, probably soon. To be effective the vaccine must be administered at least 2 weeks before the epidemic or preferably 2-3 months before influenza is expected.
General Influenza vaccination in children: As per Indian academy of pediatrics (IAP) the r ecommendations for the influenza vaccine use in India are that it can be administered in children who have: congenital or acquired immunodeficiency, chronic cardiac, pulmonary, hematologic, renal, liver disease and diabetes mellitus, children on long term aspirin therapy, any neurologic disease that might cause respiratory compromise or impair ability to handle secretions, asthma requiring oral steroids. The vaccine used in India is killed one and is administered intramuscularly, the dose being 0.25 ml in children below three years and 0.5 ml thereafter. Side effects are mild and include fever, rash and injection site reactions. The link between currently available influenza vaccines and Gullain Barre Syndrome (GBS) is equivocal and if present is less than 1 case per million people vaccinated. However the vaccine should preferably be avoided in patients with history of GBS and who are not at high risk of severe influenza related complications. The vaccine should be administered with caution in patients with history of severe egg allergy only if expected benefits outweigh risks. In countries like the USA , influenza vaccine is additionally recommended for all women likely to be pregnant in the influenza season, health care workers, all children aged 6 months to 18 years and all contacts of children with high risk conditions/healthy children less than 5 years of age. However due to lack of accurate data on the burden of disease in India and competing health priorities, the IAPCOI does not recommend the use of the vaccine in these groups. The influenza vaccines are given before the peak influenza season. When used for the first time in children 6 months to less than 9 years of age the vaccines are given as 2 doses 1 month apart; only one dose is sufficient 9 years and above. Revaccination is recommended with a single annual dose (irrespective of age) and even if the vaccine antigenic composition does not change. It is pertinent to note, that from the valid institutional studies done in India , influenza vaccination appears to have limited efficacy and effectiveness; hence is not recommended for routine use, except in conditions mentioned above.
The system of producing and distributing influenza vaccine needs proper planning as per its technicality and availability is concerned. Goal should be to develop a new cell-culture–based vaccine that includes antigens that are present in all subtypes of influenza virus, that do not change from year to year, and that can be made available to the entire world population.
John Bartlett's Postmortem on 2009 H1N1 (Influenza A): 10 Valuable Lessons
John G. Bartlett, MD
Posted: 06/15/2010
Information from Industry
Top Ten Lessons From H1N1
It may be premature for this analysis since we have had 2 waves of influenza and no one can exclude the possibility of a third wave. Nevertheless, it is a good time to gather the major lessons learned to date. My "top 10" list (in no particular order) is the following:
1. Current surveillance systems do not seem to work. Before the 2009 (H1N1) pandemic began, it was believed that the next pandemic would come from Asia , where surveillance systems were established on the basis of this prediction. The next pandemic was supposed to be a new strain of influenza such as H5N1, and it was expected to be associated with a high mortality rate. Instead, the pandemic came from Mexico, it involved a variant of H1N1 (the oldest of all known strains), and the mortality seemed extraordinarily low, about 0.02% compared with mortality from Spanish flu, which at 2.4% was about 100-fold more lethal.
2. New risks for infection have emerged. The highest incidence of infection was in the age category 10-19 years, and most cases, by far, occurred in persons < 50 years of age. In addition to young age as a risk factor, other important and somewhat surprising risks for poor outcome were obesity and pregnancy. For instance, the odds ratio for death among patients with morbid obesity (body mass index > 40 kg/m 2 ) was 7.6. [1] Among pregnant women, the odds ratio for admission to the intensive care unit was 7.4 for all pregnant women and 13.2 for those in the third trimester. [2]
3. The mortality data are deceptive. Total mortality estimated by the Centers for Disease Control and Prevention (CDC) was approximately 12,300 persons in the United States . As noted, this flu seemed to displace seasonal influenza almost completely, and the anticipated annual mortality rate associated with seasonal flu is 36,000. Thus, a glance at the numbers appears to show a great advantage for the pandemic (H1N1). However, with seasonal flu, 90% of lethal cases are in persons > 65 years of age; in pandemic flu for 2009, almost 90% of deaths were in persons < 65 years of age. Analysis of these data by life-years lost indicates that this pandemic influenza was substantially worse than most flu seasons. [3]
4. Universal vaccine for influenza is beneficial. A series of reports by Kwong and colleagues from Ontario , Canada compared outcomes of universal influenza vaccination in Ontario with those in Canadian provinces that did not have recommendations for universal vaccination. [4-6] The team from Ontario documented a reduction in illness that translated to 144,000 fewer cases by analyzing the number of respiratory antibiotic prescriptions before and after institution of universal vaccination. [4] Further research on this project indicated a 40%-70% reduction in rates of mortality, hospitalization, use of the emergency department, and physician visits. [5] Economic analyses showed that universal vaccination was also highly cost-effective. [6] This experience is particularly important in view of the recent recommendation by the CDC for influenza vaccine for all persons in the United States > 6 months of age. It must be emphasized that this simply means that vaccination is recommended, but it is up to us to make it work. Influenza vaccination must be readily available in malls, work places, and pharmacies, and it must be cheap or free.
5. Healthcare workers need to receive influenza vaccination. The incredibly embarrassing record of healthcare workers (HCWs) in getting influenza vaccination has been discussed often. In most years, the rate of HCW vaccination averages about 45%-50%, but for the 2009 H1N1 strain the national rate for HCWs was only 36%. The issue of mandatory vaccination for HCWs was also controversial. One healthcare system (BJC HealthCare, St. Louis , Missouri ) found that in most seasons, only 32%-54% of HCWs in their system received the influenza vaccine, so BJC made it mandatory as a contingency of employment. With this policy, a vaccination rate for 25,980 HCWs of 98.4% was reported; 0.4% had religious exemptions, 1.2% had medical exemptions, and 8 were fired. [7]
6. The surgical mask wins (maybe). The continuing debate about the relative merits of the N95 respirator mask versus the standard surgical mask to prevent transmission of influenza virus among HCWs was tested in Canada . [8] The study included 478 nurses who were randomly assigned to use either the N95 mask or a conventional surgical mask. The nurses were monitored for evidence of influenza or other viral respiratory tract infections. Of nurses with complete follow-up, the results for surgical masks showed infections in 50 of 212 (24%) compared with 48 of 210 (23%) in nurses who wore fit-tested N95 masks. The investigators concluded that the surgical and N95 masks are equally effective, but surgical masks were also cheap, comfortable, and in great supply. More recently, the Society for Hospital Epidemiology of America (SHEA) at their April 2010 meeting voted to recommend surgical masks. [9] (Note: the CDC still seems to favor the N95 fit-tested masksthat we all hate, but this might change).
7. The epidemic can be tracked with the Internet. The New England Journal of Medicin e developed a somewhat novel method of tracking the epidemic of influenza around the world by using news reports and health reports from diverse sources. [10] Some 87,000 sources of information were "filtered" for validity and then used to display a time sequence for global dissemination of influenza, which was readily available to anyone with Internet access. It should be noted that Google did something similar by identifying and tracking the keywords used by consumers seeking information about influenza-like illness. Google was then able to map the US epidemic in real time, and could even predict epidemics about 2 weeks earlier than the CDC. [11]
8. Vaccine production needs to be improved. The current vaccine production system requires eggs and takes 6 months. This year's epidemic was a painful example of our current limitations in vaccine production capacity and speed -- the promised large supply of vaccine did not arrive until the second peak had already started to decline. New technologies are now being pursued that will shorten the production time and magnify the yield by using molecular techniques. [12]
9. Diagnostic testing faces limitations. Polymerase chain reaction has now replaced culture as the gold standard for influenza virus detection. The rapid test used in emergency departments and clinic settings has good specificity but sensitivity of only 60%-70%; thus, a negative test result does not exclude the diagnosis of influenza. This point is emphasized by the many diagnostic errors that resulted in withholding treatment from some patients who needed it. [13]
10. How did the 2009 pandemic (H1N1) kill patients? Early reports showed that primary influenza pneumonia caused by 2009 pandemic (H1N1) histopathologically resembled the highly fatal avian (H5N1) infection. [14] The pathology of 2009 H1N1 (diffuse alveolar damage, intra-alveolar hemorrhage, and the detection of viral antigens within pneumocytes) is quite different from what is found after death from the usual seasonal flu. The other major factor that contributed to pulmonary failure with 2009 (H1N1) was bacterial infection, which was found by the CDC by using a special stain technique, in about one third of fatal cases. [15] Less surprising was the fact that some of the same pathogens found with bacterial infections in the pandemic of 1918-1919 ( Streptococcus pneumoniae , Staphylococcus aureus, and group A streptococci) were also found with 2009 (H1N1) influenza-associated infections. [16] These are treatable pathogens, a fact that is important to remember in seriously ill patients.
Summary
The experience with the 2009 Influenza H1N1 pandemic may be the most instructive flu season we have had in decades. Almost unprecedented engagement of the public was evident: public health officials, government, science, and industry. Many will count and lament the failures, but the truth is that we are likely to be much better prepared to deal with multiple influenza-related issues in the future. These include issues about masks, surge capacity, universal vaccine, use of Internet for communications and epidemiology, diagnostic testing, and school closing as an attempt (although failed) to control influenza. What we still don't know is how to get people vaccinated, how to optionally use antiviral drugs, how to make a vaccine in large amounts in less than 6 months, and how to define a pandemic.
Sheikh M Ashraf, Registrar in Pediatrics, SKIMS Medical College , Bemina Srinagar.
E-mail: [email protected]
