The quest for vaccines
In times of SARS-CoV-2 (Coronavirus), which causes COVID-19, a disease with a complex pathology, other microorganisms have joined in its attack against COVID-19 patients. Around 15% of hospitalized patients with COVID-19 develop secondary infections [“Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study”; Fei Zhou et al., Lancet 2020; 395: 1054–62]: microorganisms, mainly bacteria, that cause pneumonia, sepsis, and other lethal complications.
It is well known that a significant percentage of hospitalized patients will suffer from life-threatening nosocomial infections (hospital acquired infections) that are almost impossible to combat with any kind of antibiotics due to antibiotic-resistant microorganisms, bacteria and fungi, the so-called superbugs.
The WHO prioritizes 3 bacterial species as most critical worldwide: the carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, and carbapenem-resistant + 3rd generation cephalosporin-resistant Enterobacteriaceae to which belong strains like Klebsiella pneumonia, E. coli, and others.
Multidrug-resistant germs caused worldwide 700.000 deaths in 2018, almost double of deaths caused by SARS-CoV-2 until now. The costs associated with infections caused by superbugs reached 40.000 million USD in 2018, a figure raising every year with the increasing incidence of difficult to treat antibiotic-resistant strains.
COVID-19 patients in their most severe stage are especially vulnerable because they stay hospitalized for several weeks, which gives germs the opportunity to infect them. MDs are aware of the great risk of secondary infections that this patients face, and therefore perform early detection and prescription of antibiotic treatment. Infections by multi-resistant bacteria is one of the collateral damages of the current pandemic. The massive prescription of azithromycin, and other antibiotics to tackle secondary COVID-19 infections could be a stimulus to further accelerate the worldwide increase in bacterial resistance. 10 million deaths annually from infections of multidrug-resistant germs are expected by 2050. The near future will show until what extent the COVID-19 pandemic will accelerate this critical and imminent problem for the humanity.
Vaccination against SARS-CoV-2 still needs to show that it will be the solution against COVID-19. But what we can say for now is that vaccines have a proven track record of tackling with antimicrobial resistance.
Pneumococcal infections are common in young children, but older adults are at greatest risk of serious illness and death. The 13-valent pneumococcal conjugate vaccine (PCV13), which the FDA licensed in 2010, protects people from 13 types of pneumococcus, including resistant forms. This vaccine prevented more than 30.000 cases of invasive pneumococcal disease and 3.000 deaths from 2010 to 2013 alone.
Since the 1980s, the H. influenzae b vaccination has resulted in a dramatic reduction in incidence – nearly eliminating H. influenzae b disease in young children. Decreased nasopharyngeal carriage also resulted in extended population-wide protection through herd protection effects, which may represent approximately two thirds of prevented infections [CDC – Centers for Disease Control and. Direct and indirect effects of routine vaccination of children with 7-valent pneumococcal conjugate vaccine on incidence of invasive pneumococcal disease- -United States, 1998-2003. MMWR. Morb. Mortal. Wkly. Rep. (2005)]. This reduction in H. influenzae b incidence was associated with a significant decrease in the prevalence of the beta-lactamase producing strains that are resistant to many common broad-spectrum antibiotics.
Both vaccines have an additional “indirect” effect of reducing antibiotic use and therefore selection pressure on pathogens, which drives the development of drug resistance. Universal coverage with 13-valent S. pneumoniae vaccination could avoid approximately 11,4 million doses of antibiotic use per year in children and H. influenzae b vaccination significantly reduces outpatient antibiotic use [Kingwell, K. Vaccines take a shot at antimicrobial resistance. Nat. Rev. Drug Discov. 17, 229 (2018)].
Vaxdyn S.L., based in Seville (Spain) is currently developing with international partners a 3-valent vaccine against A. baumannii, P. aeruginosa, and K. pneumoniae. There is a strong support from key international organizations to take Vaxdyn’s program to clinical stage, since the vaccine will create an immunity shield against the major antibiotic-resistant respiratory pathogens in the vulnerable population, saving millions of lives and halting the economic impact of these superbugs. Major pharmaceutical companies are waiting for results from the clinical phase to take Vaxdyn’s vaccine to the market.
Connectem is a Healthcare Business Consulting in the field of Pharma/Biotech, Iin Vitro Diagnostics, Medical Devices and Consumer Health.
Connectem is currently collaborating with Vaxdyn in its Fundraising process.
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