This text has a solid bibliographic base, of the best science, which is summarized in the references that goes to the end. You can just read the text, or you can consult the scientific papers and decide with your own criteria.
1. Vaccines work?
Yes. There are vaccines that produce immense benefits, such as those for measles, polio, tetanus, diphtheria, rabies, etc. Their benefits depend on the circumstances, and those benefits in developed societies represent an additional six days of life expectancy.
2. How do you explain the relative value of vaccines?
Because infections are diseases in which the infectious agent is key, but also the infected subject and the environment. For example, in developed societies the best alternative to rotavirus diarrhea is hand washing, not the vaccine (which is essential in impoverished societies with water supply problems). Another example, in Madagascar, highlights the importance of good nutrition as a defense against infections, since a recent measles epidemic due to lack of vaccine left more than 100,000 cases and more than 1,000 deaths, these being basically malnourished children (“ measles was the cause of death, but the shroud was put by hunger”).
3. Is there an appropriate use of vaccines?
Yes. Vaccines are drugs and have their indications and forms of use that allow us to achieve the best results. Correct and rational use also implies considering the best alternative, whether it is the vaccine or other actions, since sometimes the ideal is just not to have to use the vaccine; for example, the vaccine against cholera, which is used only when there is not a good water supply and sewage-treatment system. Or the vaccine against tuberculosis, only useful in childhood in situations of poverty and overcrowding.
4. Are there vaccines of different effectiveness?
Yes. We can distinguish between three types of vaccines: 1 / excellent vaccines, such as yellow fever, which produce long-lasting and intensely protective effects, 2 / “need to improve” vaccines such as whooping cough, which must be given even at pregnant women to protect newborns to overcome its limited impact in another case (in addition, there is no such vaccine for “pertussis”, but a triple one, for pertussis, tetanus and diphtheria), and 3 / there are “failed vaccines”, such as of the flu (influenza).
5. Why is the flu (influenza) vaccine a “failed vaccine”?
Because its effect, if any, lasts a little over two months. That is why it must be renewed every year, regardless of whether the viruses change depending on the season (1,2,3). For example, sometimes the exact same vaccine has been given in consecutive seasons; thus “For 2014-15, the licensed vaccine will contain the same viral strains as the previous 2013-14 vaccine. (4) If the shot is in September in the boreal hemisphere its effect would not reach the season of the seasonal winter flu (December-January).
6. But is the flu vaccine good for anything?
No. That is, it has adverse effects without benefits. The flu vaccine does not reduce flu complications, hospitalizations, or deaths (5,6,7), nor does it prevent its transmission, nor does it produce herd immunity. Cochrane Reviews (8,9,10,11) have repeatedly shown this: the flu vaccine is not effective in childhood, in adults, in old age, [in pregnancy (12)]. Regarding “risk groups”, some usefulness is only shown in patients with emphysema-COPD. I will be the first to recommend the flu vaccine the day there is one that works, but I cannot recommend one whose effectiveness is primarily measured by its ability to decrease outpatient doctor visits for “lab confirmed influenza,” and it is around 35-40% (13,14,15,16). This decrease, moreover, does not reduce the frequency of “flu-like cases” of acute respiratory infection since it seems that the other germs occupy the “empty niche” of the flu itself (17).
7. Is flu important?
Yes and no, it depends; in most of the cases, no. The flu is produced by the influenza virus, of which there are several types, and its damage is added to that of the different germs (about 200 in total) that cause acute respiratory infection of the “flu-like sindrome”, such as the sintitial virus, adenovirus, parainfluenza, rhinovirus, coronavirus and others. Of the “flu-like symptoms”, approximately 10% are caused by influenza viruses. Each year, during the weeks of winter seasonal flu, an estimated 18% of the population is infected with the flu, but the vast majority (75%) do not have any symptoms, nor notice them, and of those who have symptoms, less than 1% end up in hospital admission (18). However, in some cases the flu is complicated, especially in patients with serious and terminal illnesses. But flu mortality cannot be used to promote the flu vaccine, as it has no capacity to lower it (19). For example, in the United States, more and more people are getting vaccinated against the flu, up to more than 150 million people, having no effect on flu mortality (20).
8. Does the flu vaccine decrease human-to-human transmission, for example from healthcare professionals to patients, or from grandparents to grandchildren, or from teachers to students, or from workers to the elderly in nursing homes, and vice versa?
No. The flu vaccine does not produce herd immunity, and it does not protect healthcare professionals or protect their patients; idem grandparents and grandchildren, teachers and students and workers and the elderly (21,22,23,24,25). The effort to vaccinate health personnel is not reasonable as there are many studies that show the uselessness of such an effort. On the other hand, health professionals have the same risk of getting the flu as workers in other areas of the same age (26).
9. Do those vaccinated against flu shed more flu viruses?
Yes. The flu vaccine does not prevent you from getting the flu, and people who are vaccinated against flu who get the flu shed more flu viruses. The flu vaccination is associated with the production of aerosols with the flu virus in the air that is exhaled. The flu-vaccinated person who has the flu exhales 6.3 times the number of flu virus particles than the unvaccinated person (27).
10. What adverse effects does the flu vaccine have?
The flu vaccine has many adverse effects, from mild to very serious. The worst, the narcolepsy epidemic that produced the 2009-2010 influenza A (H1N1) vaccine, which affected hundreds of young people (28,29,30,31). It also caused another epidemic, this one of Guillain Barré syndrome, in 1976 (32). In general: intense local reaction (pain, redness, inflammation, ecchymosis, induration), fever, headache, sweating, myalgia, arthralgia, chills, seizures, urticaria, anaphylaxis, vasculitis, thrombocytopenia, lymphadenopathy, angioedema, paresthesia, Bell’s palsy (facial), Guillain-Barré syndrome, demyelinating disorders, neuritis, encephalomyelitis and other adverse effects (33). In addition, after vaccination there are false positives in the AIDS test. Season after season revaccination is associated in pregnant women with a 7.7 times greater risk of spontaneous abortion in the following 29 days than if they are not vaccinated (34,35).
11. Is there legal protection against the adverse effects of the flu vaccine?
Yes. But in many coutries there is not a rapid no-fault compensation non-judicial system of the type that exists in developed countries (Germany, South Korea, Denmark, the United States, France, Italy, Japan, etc) (36). Neither in Spain, nor in Portugal, nor in any Latin American country is there a mechanism for redress without trial for damages caused by vaccines (37). If you are injured, you will have to establish a complex and expensive individual process to obtain compensation (which will basically go into the pocket of the lawyers).
12. Why do all authorities and experts recommend the flu vaccine?
I do not know. They will know the interests that move them. From a scientific and sociological point of view, such a recommendation leads to the discrediting of vaccines that provide benefits. There is an abyss between the official recommendations on the flu vaccine and the evidence of benefits of the same (38). It is a serious failure of industries and governments to tolerate the lack of expected significant clinical effects of the flu vaccine. And it is a discredit of scientists and experts their continuous conflicts of interest such as those of the “European Scientific Working group on Influenza” (ESWI) sponsored by the very industries that produce the influenza vaccine (39), or as the never declared conflicts of the experts who advised the World Health Organization on the influenza A (H1N1) pandemic (40).
13. But there will be something for them to defend the flu vaccine, right?
There is something, yes. There are observational studies that make the flu vaccine miraculous, such as the classic one that demonstrated its association with a 30% decrease in mortality in the elderly from all causes (the flu vaccine decreases, according to this study, deaths from all causes, which implies decreasing even deaths from traffic accidents, domestic accidents, heart attacks, strokes and cancer). Other observational studies show the association of vaccination with lower hospitalizations and mortality, but in reality they only show that the healthiest are vaccinated against influenza, not the efficacy of the vaccine.
14. “By vaccinating against the flu we will avoid confusing the pictures of flu with those of # COVID19”, right?
No. For three reasons: 1 / in the best of cases the flu vaccine only prevents 1 flu in every 100 vaccinated (in 99 it is not worth) (41) , 2 / in clinical practice the “flu-like symptoms” caused by the germs of acute upper respiratory infections are often indistinguishable. For example, “sentinel” doctors, specially trained to diagnose influenza, are wrong in about half of the suspected “flu-like” cases (42), and 3 / even during the “peak” of seasonal winter flu most of the hospitalizations are not due to the influenza virus, but to the set of other respiratory viruses (rhinovirus, syncytial virus, coronavirus and others) (43).
15. If we get vaccinated against the flu, will there be less overload in the emergency room, and in health centers and hospitals?
No. Every flu season is bad. Every year millions of citizens are vaccinated against the flu, and each year the demand for health grows and grows during the seasonal winter flu season. The emergencies are saturated and the hospital and primary care services are overloaded even though a large part of the population is vaccinated (44). This is to be expected, given that the flu vaccine is a “failed” vaccine, which prevents neither the flu nor the complications of the disease.
16. The seasonal winter flu will be much worse this year, exacerbated by the pandemic of the new #coronavirus # SARS-2-CoV, right?
No, no, that is pure speculation. In fact, we have experience and data that show that with the pandemic, other germs that cause acute upper respiratory illnesses have almost “disappeared”. For example, in Argentina (45) during the winter the flu drastically decreased, but not because of the flu vaccine, since the cases produced by many other germs that cause acute upper respiratory infections (flu, parainfluenza, adenovirus, syncytial virus, etc.) also decreased. The same has happened in Australia (46), South Korea (47), Japan (48), New Zealand (49) and other countries where mortality from influenza has almost disappeared.
17. Why this decrease in the frequency and severity of flu in the winter during the #COVID19 pandemic?
We do not know. The most logical thing is that it is due to simple hand washing, the most effective measure against the flu (also to the least social interaction, due to the measures against the pandemic) (50). Health professionals washed their hands before the pandemic in less than half of the cases where it would be mandatory, and lay people in less than a quarter. If with the pandemic due to the new #coronavirus, professionals and lay people have begun to wash their hands, its effect must be shocking, as shown by several previous studies regarding hand washing (which is “the best vaccine” against upper acute respiratory infections, flu included). In addition, perhaps, the new coronavirus “displaces” other germs and prevents their spread in the community, but this is speculative, as hand washing and less social interaction have more impact on flu and other viruses and less impact on the spread of the new coronavirus.
The flu vaccine is a failed vaccine, useless at best, that discredits vaccines in general. The situation created by the #COVID19 pandemic does not change the recommendation not to use it.
(1) Intraseason Waning of Influenza Vaccine Effectiveness https://academic.oup.com/cid/article/68/10/1623/5094689
(2) How long do vaccines last? The surprising answers may help protect people longer https://www.sciencemag.org/news/2019/04/how-long-do-vaccines-last-surprising-answers-may-help-protect-people-longer
(3) Why flu vaccines don’t protect people for long https://www.sciencemag.org/news/2020/08/why-flu-vaccines-don-t-protect-people-long?utm_campaign=news_daily_2020-08-13&et_rid=438568703&et_cid=3445815
(4) Influenza Vaccine Composition for the 2014–15 Season- For 2014–15, U.S.-licensed influenza vaccines will contain the same vaccine virus strains as those in the 2013–14 vaccine. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6332a3.htm#Influenza_Vaccine_Composition
(5) Is the influenza vaccine effective in decreasing infection, hospitalization, pneumonia, and mortality in healthy adults?
(6) The Effect of Influenza Vaccination for the Elderly on Hospitalization and Mortality https://www.acpjournals.org/doi/10.7326/M19-3075
(7) The efficacy of influenza vaccine in elderly persons. A meta-analysis and review of the literature https://pubmed.ncbi.nlm.nih.gov/7661497/
(8) Influenza: evidence from Cochrane Reviews https://www.cochranelibrary.com/es/collections/doi/10.1002/14651858.SC000006/full/es?cookiesEnabled
(9) Three updated Cochrane Reviews assessing the effectiveness of influenza vaccines. https://www.cochrane.org/news/featured-review-three-updated-cochrane-reviews-assessing-effectiveness-influenza-vaccines
(10) Why have three long-running Cochrane Reviews on influenza vaccines been stabilised?
(11) The flu vaccine is being oversold – it’s not that effective https://theconversation.com/the-flu-vaccine-is-being-oversold-its-not-that-effective-97688
(12) Influenza Vaccinations for All Pregnant Women? Better Evidence Is Needed https://pubmed.ncbi.nlm.nih.gov/30231471/
(13) CDC Seasonal Flu Vaccine Effectiveness Studies https://www.cdc.gov/flu/vaccines-work/effectiveness-studies.htm
(14) Immune History and Influenza Vaccine Effectiveness https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027411/
(15)Influenza vaccine effectiveness https://www.ecdc.europa.eu/en/seasonal-influenza/prevention-and-control/vaccine-effectiveness
(16) Interim Estimates of 2019–20 Seasonal Influenza Vaccine Effectiveness — United States, February 2020 https://www.cdc.gov/mmwr/volumes/69/wr/mm6907a1.htm
(17) Influenza-like Illness Incidence Is Not Reduced by Influenza Vaccination in a Cohort of Older Adults, Despite Effectively Reducing Laboratory-Confirmed Influenza Virus Infections https://academic.oup.com/jid/article/216/4/415/3958807
(18) Comparative community burden and severity of seasonal and pandemic infl uenza: results of the Flu Watch cohort study https://researchonline.lshtm.ac.uk/id/eprint/1649021/1/1-s2.0-S2213260014700347-main.pdf__tid%3Dbd0c032e-c134-11e5-a13d-00000aacb362%26acdnat%3D1453486975_5644878c2207d61c89a374887c3b8f0f
(19) Influenza: marketing vaccine by marketing disease https://www.bmj.com/content/346/bmj.f3037
(20) Infectious Disease Mortality Trends in the United States, 1980-2014 https://jamanetwork.com/journals/jama/fullarticle/2585966
(21) Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions
(22) Influenza Vaccine Effectiveness in the Community and the Household https://academic.oup.com/cid/article/56/10/1363/404283
(23) Influenza Vaccination of Healthcare Workers: Critical Analysis of the Evidence for Patient Benefit Underpinning Policies of Enforcement https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0163586
(24) Should flu shots be mandatory for health-care workers? https://theconversation.com/should-flu-shots-be-mandatory-for-health-care-workers-14039
(25) School absenteeism among school‐aged children with medically attended acute viral respiratory illness during three influenza seasons, 2012‐2013 through 2014‐2015 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5410714/
(26) Are healthcare personnel at higher risk of seasonal influenza than other working adults?
(27) Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community https://www.pnas.org/content/pnas/early/2018/01/17/1716561115.full.pdf
(28) Risk of narcolepsy in children and young people receiving AS03 adjuvanted pandemic A/H1N1 2009 influenza vaccine: retrospective analysis https://www.bmj.com/content/346/bmj.f794.short
(29) Narcolepsy in association with pandemic influenza vaccination https://www.ecdc.europa.eu/sites/portal/files/media/en/publications/Publications/Vaesco%20report%20FINAL%20with%20cover.pdf
(30) Pandemrix vaccine: why was the public not told of early warning signs?https://www.bmj.com/content/362/bmj.k3948
(31) The 2009 H1N1 pandemic, vaccine-associated narcolepsy, and the politics of risk and harm
(32) Reflections on the 1976 Swine Flu Vaccination Program https://wwwnc.cdc.gov/eid/article/12/1/05-1007_article
(33) FLUARIX TETRA (Influenza virus haemagglutinin) suspension for injection https://au.gsk.com/media/484448/fluarix_tetra_pi_au.pdf
(34) Association of spontaneous abortion with receipt of inactivated influenza vaccine containing H1N1pdm09 in 2010–11 and 2011–12 https://www.sciencedirect.com/science/article/pii/S0264410X17308666
(35) Reporting flu vaccine science https://www.bmj.com/content/360/bmj.k15
(36) No-fault compensation following adverse events attributed to vaccination: a review of international programmes
(37) Vaccine injury redress programmes: an evidence review https://www.lenus.ie/bitstream/handle/10147/628020/Vaccine_injury_redress_programmes._Final_report.pdf?sequence=1&fbclid=IwAR0z17dcPwV0BZ7s3BL1xlbx5CNIAcRsp1voz4NBerBe1eFlriEW7BQovtM
(38) Influenza vaccination: policy versus evidence https://www.bmj.com/content/333/7574/912
(39) ESWI. “European Scientific Working group on Influenza” https://eswi.org/
(40) WHO and the pandemic flu “conspiracies” https://www.bmj.com/bmj/section-pdf/186584?path=/bmj/340/7759/Feature.full.pdf
(41) The flu vaccine is being oversold – it’s not that effective https://theconversation.com/the-flu-vaccine-is-being-oversold-its-not-that-effective-97688
(42) Influenza vaccine effectiveness assessment through sentinel virological data in three post-pandemic seasons
(43) Other Respiratory Viruses Are Important Contributors to Adult Respiratory Hospitalizations and Mortality Even During Peak Weeks of the Influenza Season https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4281811/
(44) With Mass. Flu Season In Full Swing, Emergency Department Reports Crowding. https://www.wbur.org/commonhealth/2020/01/09/flu-season-mass-emergency-crowding
(45) Boletín Integrado de Vigilancia. Nº504 SE 28/2020 https://www.argentina.gob.ar/sites/default/files/biv_504_se_28.pdf
(46) Australia sees huge decrease in flu cases due to coronavirus measures https://www.newscientist.com/article/2242113-australia-sees-huge-decrease-in-flu-cases-due-to-coronavirus-measures/#ixzz6WUuNO8Ga
(47) Collateral benefits on other respiratory infections during fighting COVID-19 https://www.sciencedirect.com/science/article/pii/S0025775320303535?via%3Dihub
(48) Seasonal Influenza Activity During the SARS-CoV-2 Outbreak in Japan https://jamanetwork.com/journals/jama/fullarticle/2764657
(49) Coronavirus: While Covid-19 takes lives around the world, New Zealand’s response has led to fewer deaths from all causes https://www.stuff.co.nz/national/health/coronavirus/122476223/coronavirus-while-covid19-takes-lives-around-the-world-new-zealands-response-has-led-to-fewer-deaths-from-all-causes
(50) Physical interventions to interrupt or reduce the spread of respiratory viruses https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6993921/ https://www.medrxiv.org/content/10.1101/2020.03.30.20047217v2